1. Batch simulate airfoil for different Reynolds numbers so that the whole range of the wing is covered (speed you want to simulate + chord length on the root and tip). Fast way to calculate Reynolds numbers and mach numbers for your simulation case is to use this web page:
http://aero.stanford.edu/StdAtm.html
Use the metric values.

2. When you know your Mach number and Reynolds number range (ranging from tip to root), simulate the airfoil of your choice on QFLR5 on that range. Using batch analysis feature.

Please note that it can take significant amount of time to batch analysis all the airfoils you want to simulate (e.g. if your wing is going to use more than one airfoil for example, and if you want to compare it to other wings which have different airfoils).

3. Go to Wing and Plane Design. Select from Unit preferences. Replace millimeter units with meter, so you want m/s, m^2, m for length etc.

4. Select Define wing from the menu. A window with a spreadsheet appears.

5. Define the wing by entering the y positions (you can define as many as you like). For simple taper it is enough to enter root to y position 0 and then tip to the position where the wing ends. For 12 meters long wing this position is 6 meters (as the plane is quite often symmetric). Select chord length for the root and tip. Select dihedral and twist for the root and tip. Select foil for the root and tip. Select the number of panels you want for the simulation. The more panels, the more accurate. Please note that the dimensions here affect to the Reynolds number, so if your simulation later says it is out of flight envelope, it means that you have not simulated in the Foil direct analysis section the appropriate Reynolds number range, something is missing. Please go back to the web site stated above and check your Reynolds numbers.

6. When you have a wing with desired shape with desired airfoils, click Save and Close from the bottom.

8. Select from Polars menu Define analysis. Select your simulation speed. Please note that this affects your Reynolds number. You need to know at this point your desired speed you want to fly. Select plane weight and moment location on the wing. You can
then select 3D panels. For example I have 150 kt, 800 kg, 0.40 m, 0.00, 0.00.

9. Analysis settings on the right, uncheck sequence if you are interested in one angle of attack only. This most likely is the case if you want to simulate a constant speed (e.g. the 150 kts described above). Then click Analyze and your wing is analyzed for that angle of attack.

Some examples of analyzed wings:

NACA4415:

KS20 (same wing):

NASA NLF414F (same wing again):

Get it from here:
http://www.katix.org/karoliina/packages/QFLR5.app.tar.gz

Here is a recording of Maemo Summit 2009 Opening sequence which features my music.
http://www.youtube.com/watch?v=dqsMAkKrXJ8

Maemo Summit 2009 Opening video on Youtube

My computer just finished uploading the opening of 2009 Maemo Summit to Youtube. It features the N900 video and Peter Schneider’s welcome. If you see embedded version of this video, please make sure you click the Youtube logo to see it in HD (after clicking HD, you can click full screen to get the most benefit out of it).

The video Peter Schneider plays features my music. The video content is from two Nokia N900 videos that I remixed together. I edited the soundtrack of this video so that the music part mixes sound from the event and the original soundtrack so that the music has higher fidelity than what you could record on the N900 hall on Maemo Summit at Westgasfabrik.

Unfortunately I was kind of busy with releasing this (since people seem to be eager to see the videos now rather than later), so editing and filtering is not best possible and there is for example some visible noise on it. The film was filmed with Canon EOS 5D mark II with ISO setting 25600 (the very high ISO explains why there is some noise in the video – in same conditions my old video camera would have turned almost black and white and greenish and would have produced quite low resolution video).

Anyway, have fun with the video: http://www.youtube.com/watch?v=dqsMAkKrXJ8.

I created this airfoil one day. I was looking for getting high L/D at low Re. This is pretty nice. I tried simulations as low as Re 100000-300000 (not included in here, you can try by yourself with QFLR5).

Airfoil KSNLF51:

KSNLF51 L/D graph:

Data file: http://www.katix.org/karoliina/airfoils/KSNLF51.DAT

Polars:
Re 1 million, Mach 0.3
http://www.katix.org/karoliina/airfoils/KSNLF51_T1_Re1.00_M0.30_N9.0.txt

Re 3 millions, Mach 0.3
http://www.katix.org/karoliina/airfoils/KSNLF51_T1_Re3.00_M0.30_N9.0.txt

Re 5 millions, Mach 0.3
http://www.katix.org/karoliina/airfoils/KSNLF51_T1_Re5.00_M0.30_N9.0.txt

License: Creative Commons Share-a-like

Comparison between some airfoils:

http://www.geuz.org/gmsh/
http://www.opencfd.co.uk/openfoam/

You need the followings:
- 1 liter: Tropicana Pineapple juice.
- 1 package of coconut milk
- 3 bananas

Mix together until the mix is smooth (with power mixer).

I have been trying to come up with my own formula (that differs from the various CAFE formulas to have a weighting that suits me better). I found another interesting comparative formula, the AEI.

AEI = (W0*U0)/hp

where W0 is the gross weight in lbs
where U0 is the free stream velocity in ft/s
where the hp is the horse power required

In other words for Diamond DA40 this is:

W0=1200 kg = 2640 lbs
U0= 214 ft/s (127 kts cruise at 10000 ft)
hp_cruise=90

=>

AEI(Diamond DA40) = (2640*214)/90
AEI(Diamond DA40) = 6277

Unlike the CAFE formula this has no weighting for these parameters.
If I would like to make my formula based on this, I might want to weight the hp a bit more.
That is because the lower the hp figure gets, the better is the fuel economy if everything else remains constant.

Why this index is good? Because it isolates aerodynamics from structural engineering and does not care how much useful load the craft has. It only considers the aerodynamically important point, how much power is required to move the mass forwards and at the same time keep it on air.

Bruce Carmichael: Minimizing fuselage drag. http://www.aerorag.com/resource/aircraft/aerodynamics/carmichael/min_fus_drag_carmichael.pdf

Here is a link to the article by AOPA about Klaus Savier’s Vari-Ez.

“For all these guys that think magnetos are so great, I only have one question: Why don’t you put magnetos in your cars?” Read more by clicking the link below:

http://www.aopa.org/aircraft/articles/2008/081230100mpg.html?WT.mc_id=090102epilot&WT.mc_sect=gan

http://www.google.fi/url?sa=t&source=web&ct=res&cd=6&url=http%3A%2F%2Fsalamanca.khbo.be%3A8080%2Fdoks%2Fdo%2Ffiles%2FFiSe8a81998218eeb4e50118ef3ae0650156%2Feindwerk.pdf%3Bjsessionid%3D5E70EC2B35D00A97C21355C91E39AFE5%3FrecordId%3DSKHB8a81998218eeb4e50118ef3ae0630155&ei=0tKfSpiOCoaQsAbvkPkc&usg=AFQjCNE_pm74spwMHweSYoUJ4k-GTc4ocw&sig2=hhrDwapR25sdgbscQ8vHPA

There has bee a lots of interest around this new device and the Maemo 5 operating system. Lots of positive comments and then I have read some comments where people doubt that the transitions would be just some flash animations and not a real thing (which of course is not true). Well, this is a OpenGL hardware accelerated Maemo device, and all you see is real. Quim Gil just posted on Twitter a link to a new video showing how the Maemo UI works, if you had doubts, you can put the doubt aside and see by yourself. The user experience is slick and beautiful.

You can find the video from here:
http://www.youtube.com/watch?v=ZrYqemylpIo

In my opinion, the UI experience on the Maemo 5 has improved greatly over what it used to be and also over the competition. It is really pleasant to use and there are not so many things that would be annoying. There certainly is lots of wow, and this kind of shows the innovation these days is occuring in the mobile space rather than on desktop, desktop environments are already lagging behind and the transitions on these UIs are not so practical they are in Maemo where they are all well thought and well implemented and not just random eye candy and special FX without purpose. Maemo 5 really rocks on this segment.

There is also an article about hands on experience on N900. Slashgear is reporting from Nokia World conference. There is both video and lots of good pictures included. This shows how the device looks like rather than the UI. The video I mentioned above is better showing how the UI functions.

http://www.slashgear.com/nokia-n900-hands-on-0254743/

And here is yet another hands on video. This is also very good:
http://www.youtube.com/watch?v=Zr-BF0Gs0_E

And here is the replacement for a gaming console.

http://twitpic.com/g6smv

The Nokia N900 can be used as accelerometer equipped controller and connected to a TV. Hint for game developers: Here is the great platform to start developing games. The platform supports full OpenGL ES 2.0 and a OpenGL-ES game does not even need to care that much what Maemo version it will run on, Maemo 5, Maemo 6, and the GL is standard. It is not a bad long term investment to invest on Maemo. The N900 has a capable graphics accelerator (for this small mobile device) as can be seen from the Bounce game and from also the UI which heavily relies on the accelerated 3D graphics. The capacity of the device is great – it has plenty of RAM and there is plenty of flash too on the user’s home directory. And if the RAM would not be enough, there is also virtual memory like on any modern operating system nowadays. The games don’t need to be that simple and amateurish anymore “mobile games”, I am quite confident that anything that has been done for Wii could be done for this device, in other words, this could be used as a serious gaming device despite that is not what it was primarily targeted for (as it is Internet device really). But like computers, there are many uses for the single device. Also, the device can be always connected, so massive multiplayer games would be superb on this. Looking forward to try some serious 3rd party games in the future! Hey Austin, if you read this, please port the X-plane, I want it.

Here is an article about turbo system of the highly modified Rotax:

http://www.designnews.com/article/13660-Turbo_power_reaches_new_heights.php

Our secret N900 “The Device” is no longer so secret as it just got announced. I can’t though show yet my own videos about it (I will post them some time later, so stay tuned), but there is already plenty of announced material that might interest you. Others have already announced links to them I am sure. I really love our device and I am sure you want it too!

New site, lots of cool pictures and information:
http://maemo.nokia.com

There is a video in Youtube (not my video, but cool nonetheless):
N900 interaction documentary

I recommend watching the above video if you are eager to see (I am sure you are) how our completely renewed fancy UI works. It is very cool and it works!

There is lots of strong feelings about tractor vs. pusher propeller configuration but no exact generic answer. Here is one article about the topic. Does not make definitive answer, but gives some background for the topic:

http://www.flyingmag.com/technicalities/1582/pusher-pusher.html

Here is another article:

http://dic.academic.ru/dic.nsf/enwiki/514042

Forum discussion

Another forum discussion

http://www.aiaa.org/content.cfm?pageid=406&gTable=mtgpaper&gID=50663

Tractor (prop forward of laminar flow wing):

http://www.aiaa.org/content.cfm?pageid=406&gTable=Paper&gID=1248

Most aircraft have larger than necessary wetted area and not so optimal body shape. One could think without thinking in more detail that wetted area is saved by lofting the plane so that the engine cowling is part of the main fairing and then there is a minimum canopy added on top of that.

However, a little thinking further: which one is the shortest route always, hypotenuse or catheti? Unlike the first thing which comes to mind when looking at planes and saving wetted area, instead of having this complicated shape, actually having more volume and fairing everything in the single form actually produces not only easiest path to the airflow, but also it produces lowest possible wetted area. So making the fuselage larger by removing canopy and putting the cockpit inside the main shape decreases wetted area and drag instead of increasing it. The shallower angle for windows does not decrease the visibility – the visibility can remain still the same. The only problem comes from the optical quality of the windows – as you are looking them from angled direction, you are looking through more plexiglass than you otherwise would and it can degrade the visibility. However – the visibility directly forwards is usually not so good in single engine aircraft which have engine in the front and it is neither better on planes without engine on front since somehow designers seem to not think that people would like to see straight forward very well too. Some twin engine planes have very high panels and poor visibility forwards despite of the fact not having the engine in front would make it possible to make the forward visibility a lot better than that.

So the design on CAD system becomes easy when the shape is not complicated but super simple. And in turn the super simple shape (convex to all directions though, in that sense not so simple, but I mean it is a single loft) has the best drag coefficient and the best wetted area too. At times it feels unbelievable that the solution can be so simple (and I have difficulty to believe it myself when looking e.g. our shared ownership Diamond DA40, it has many shapes, parts and forms), but who says that it has to have so many shapes. Nobody. So it will not have so many different shapes and forms if one shape can do it all. And who says the instrument panel needs to be panel and everything laid out to the panel? Nobody again. A bit more creativity and a lot better forward visibility is achieved despite of not having a bubble canopy and despite of having a pressurized fuselage.

Blending the fuselage to the wings increases frontal area. But who cares about the frontal area. It has very little effect to the drag in airplanes. It is all about wetted area and saving in the wetted area (in addition to maximizing the laminar flow). So blending the wing decreases wetted area – hypotenuse again, it is not a good idea to follow catheti. And the air likes that too – in fuselage wing joint the airflow can not sustain laminar flow. But what if you eliminate the joint and at the same time save in the wetted area. Great stuff.

One could say that it is hard to make a door to a such fuselage. Yes it is hard to make a door. But the solution for the door is to eliminate the door. A hatch that has no hinges and that is larger than the hole is the most light weight door one can imagine. It does not require complicated mechanism to hold it on place and it does not require lots of latches. It holds on place by itself because of the air pressure differential. It can be locked with a lot lesser heavy duty mechanics from inside to the fuselage. And how to ensure the hatch does not ever get out of the hole? That is super easy too: the hole and hatch can be circular and there is no way to put a larger circle out of a smaller circular hole. Not even magicians can do that!

Now then the window problem:
- to glue windows on pressurized fuselage, how to make sure the windows don’t rip themselves out – how to glue them on place. Keep it simple and stupid solution: glue them to the inside so that they are larger than the hole in the fuselage. Now what, we have a problem that there is a dent outside of the fuselage on the window area which is really bad for the airflow. No problem again, there can be a simple non-pressurized window that is glued to the outside and faired level with the fuselage around it. It is also a fail-safe: if the windows that are exposed to outside get scratches, no problem, it does not affect the pressurized fuselage – these windows can be replaced fairly easily. And guess what, no bolts are needed, no rivets are needed, very simple.

Then how to get the blended fuselage to work with pressurization. Again super simple: the blend can be fairing on the outside and the pressure vessel can be tubular with completely circular cross section inside.

We completed the first atlantic crossing in the N756DS (Diamond DA40) on Wednesday and arrived to Helsinki-Malmi. There will be a presentation about the trip in SIL-luokka Helsinki-Malmi later. I will let you know more about it when I know more details and have prepared the presentation. If you are a reporter in a newspaper or magazine and want to write a story about our not so ordinary adventure, feel free to contact me karoliina dot t dot salminen at gmail dot com.

We received the ferry flight training from Edward Carlson.

We want to do the trip again also, if you are looking for inexpensive ferrying from USA to Finlandm or to any other European country via Denmark/Opmas, I am glad to inform that the Danish VAT will work still to next summer as followings: if you buy aircraft this year before the end of the year and complete all the agreements, according to Opmas, the plane can still benefit from the Danish VAT if it is ferried on the first half of 2010. We would be glad to help for free (no ferry flight fee) at the price of the expenses (gasoline, hotel (we choose cheapest options always), maintenance needed for the plane, airport fees). If you are interested in inexpensive ferry (or should I say delivery) flight, please contact me to the abovementioned address. You can not fly the North Atlantic for first time by yourself, but you need someone that has flown it before to get insurance (which is mandatory for the flight). We have now flown it once and are willing to help people who haven’t flown it yet and/or who do not want to fly it by themselves. The summer time is the best time for ferrying an aircraft because of weather. We will spend our summer vacation for flying your plane for free, you can not get better deal from anybody. We agree to fly the following aircraft make and models: Diamond DA40-180/G1000, Diamond DA40XL/G1000, Diamond DA40-CS/G1000, Diamond DA40-180/Avidyne, Cirrus SR20/Avidyne, Cirrus SR22/Avidyne, Cirrus SR22/Garmin Perspective or Diamond or Cirrus with any other comparable glass cockpit avionics – this list is based on our prior flying experience – we have flown Diamonds and Cirruses before. We can consider also other aircraft, but that will rise the expenses a bit since we need to get checked out to these prior flying the trip. I could estimate that most familiar of those would be Columbia 350, Columbia 400, Cessna 350 Corvalis, Cessna 400 Corvalis and these we would be glad to fly providing that we would get proper check-out before starting the trip to feel comfortable enough flying the plane in not so ideal conditions. We may not agree to fly steam-gauge IFR planes and surely will not agree to fly VFR-only equipped planes. Also we will not fly C172, because that is not suitable for the trip. We are not interested in taking unnecessary risks, we want to deliver.

We arrived safely to home Wednesday 19.7.2009 evening. The trip was finally over and i felt so good to be at home with my cats. There is lot of stories to tell, many blog articles are waiting to be published. i just need to finish them and chose pictures attached. We got around 200Gigabytes of picture and video material with our EOS 5D mk II .

Our route was following N756DS route in Great Circle mapper

That makes about 9000 Nautical miles and that is not counting yet my Instrument training in Palo Alto or that many legs were not great circle but airways via fixes. You can find more precise tracks and IFR plans from Flightaware N756DS

I quickly collected some video clips from our collection. I created this first because I really loved the
scenery in the Kulusuk, really beautiful mountains:

http://www.youtube.com/watch?v=j6aLdd7ZYmU

I have been recently a bit silent on this blog. The reason have been that I have been too busy and out of Internet most of the time. In other words, I have been flying.

I am typing this from Iceland. Our trip has been so far quite incredible:
1. from Helsinki to Miami with airliner
2. from Miami to Jacksonville with car
3. from Jacksonville to St. Louis with plane, N756DS
4. from St. Louis to Pueblo with N756DS
5. from Pueblo to Palo Alto with N756DS
6. IFR training in San Francisco Bay Area with N756DS
7. from Palo Alto to Sioux Falls with N756DS
8. from Sioux Falls to Oshkosh with N756DS
9. spent couple of days in Oskosh/Airventure 2009. Camp with Cozygirrrls.
10. from Oshkosh to Rhode Island with N756DS
11. from Rhode Island to Wabush (Canada) with N756DS. First Northern Atlantic Crossing in a small airplane was started for us. We are flying with Ed Carlson (he is a ferry flight instructor specialized in Northern Atlantic crossing).
12. from Wabush to Kuujjaq (Canada) with N756DS
13. from Kuujjaq (Canada) to Iqaluit (Canada) with N756DS
14. from Iqaluit (Canada) to Kangerlussuaq (Greenland) with N756DS
15. from Kangerlussuaq (Greenland) to Kulusuk (Greenland) with N756DS
16. from Kulusuk (Greenland) to Reykjavik (Iceland) with N756DS
17. from Reykjavik (Iceland) to EGILSSTADIR with N756DS

We will continue to Faroe Island / Vagar next. After that is either Bergen or Stavanger in Norway.

Kate has been keeping a blog about the adventure here:
http://n756ds.blogspot.com

I started my IR training in West Valley Flying Club ( www.wvfc.org ) in San Francisco area . The plan was to get fast and cheap instrument rating. Soon I noticed that if you really like to get easy IR as as quickly and fast, the San Francisco bay area is worst possible choice. If you like to get good IR with it you can fly about any busy airspace, it is excellent choice.

First surprises were that American airspace system and regulations differ a lot from European ones and San Francisco bay area airspace structure is really complicated and busy. Helsinki area is about small village compared to SF-bay area. There, Palo Alto, just one of dozens local general aviation airports has as much GA-airplanes that exists in all Finland. It was also surprise that radio fraseology differs a lot from European one and if you are non native English speaker, busy fast IFR radio communications needs some time to adapt.

It is also not the fastest and cheapest to start IR training with Cirrus SR20 with Avidyne glass cockpit. When I started the training, Cirrus was our number one alternative and WVFC did not had Diamond in this time. They charge $199 or $214 for SR20, $164 for C172/G1000 but Steam Gauge Cessna or Piper you may get around $100 . Cirrus is also not considered as ordinary airplane for WVFC, it needs minimum 11 hours type training and special check ride called phase check.

Flying club as like WVFC was not a fastest way to get training, there is also other members booking planes and flight instructors and therefore you can’t fly when you want to do so. Some flight schools may designate plane and instructor for you all of the course. This Flying club system is just not most cost efficient if you are not local but coming from distant country and need to pay hotel and car rental for every day you are flying or not. Also Silicon valley is not the cheapest place to stay.

When i started my flight training 2008 I Strongly underestimated my schedule, I scheduled one month period for flight training. It was strongly underestimated, i just could not got booked enough plane and instructor to get training completed. I spent many days just for keeping vacation, that was not bad idea at all in SF bay area. IR Training is also and work, so it is not bad idea to have some free time between sessions. I had plan to return autumn to complete training but this did not happen. In 2008 trip I also learned that many things can go wrong in paperwork. I had plan to get FAA Medical and FAA PPL . When i was already in Palo Alto, FAA told to me that they did’t approve my translated medical records because they are not translated by FAA approved translator. Even today, i don’t know what is and where to find FAA approved Finnish to English translator. For next trip, I asked doctors to write their statements in English and sign them as originals to avoid this translation problem.

I returned spring 2009 continuing my instrument training, I chose cheaper C172 G1000 plane that the club had more of them than Cirrus SR20’s and i got in practice designated flight instructor. I think that also economical depression affected so that instructors and planes were no longer so booked than spring 2008 . Now I also has basically all paperwork done. I had European JAA and FAA medical and i had file application for FAA Restricted PPL .

When I returned after one year since i had my previous instrument training, it needed several hours training just to get level where I was year ago when i left. In Spring 2009 i did written test and got basically training program done but once again bad luck with paper work. I got my FAA Restricted PPL based on European pilot’s license but i was unable to get appointment booked to San Jose FSDO and therefore I was unable to have Check ride.

Now in this trip, i finally had everything done. I had training done, I had all medicals in my hand, i had appointment booked to San Jose FSDO and I had check ride booked. The trip from Florida to Palo alto took couple of days longer than estimated and we needed to re-schedule my check ride to Monday 27 July. Now i had couple of days time to refresh my IR skills before check ride. Then Monday i was thinking that everything is ready and we started ground part of checkride but it was interrupted n beginning because there was couple on flight instructor signatures missing from my logbook. The Check ride was then re-scheduled Wednesday 29.

In Wednesday, we finally were able to begin my checkride. I had Tom Hornak as my check ride pilot. At first he went thru my application and logbook, then checked airplane documents, maintenance records etc. Then he did tho oral part, series of good questions like what i would do in complete radio failure situation, some details from approach plates, how to get weather briefing etc. Then started actual check ride, I filed flight plan to Stockton ( KSCK, route SJC V334 SUNOL V195 ECA ). In Stockton we did VOR rwy 21, touch an go, then continued GPA A to Tracy ( KTCY ) and that approach we did as partial panel. From tracy missed approach we did couple of holds and then ILS rwy 25R to Livermore. That was the check ride and I was really happy and relieved when Tom said that I passed. Finally long lasting dream and couple of years long project was completed.

About actual training, my instructors in West Valley, Scott Stauter and Brian Elliot give excellent instruction. Wvfc had excellent facilities, wide variety of planes to chose, starting from old steam gauge Cessnas to modern glass cockpit Diamond Star DA40, TwinStar DA42 Cirrus SR20 and SR22 and several G1000 Cessna 172 . They also have Frasca G1000 simulator that we used as mush as we could for my training. There is several good reasons to use simulator. With simulator you can practice mush more approaches in same time, you can practice more fault conditions than in real plane and it costs 100 dollars less for hour than aircraft.

Then there is question, should you get your instrument training with glass or with steam gauges. As my personal opinion, if you plan to fly modern glass cockpit planes, you should get your training with glass. Flying glass needs so much different skills. Reading the attitude indicator , altitude and airspeed is the easy thing. Much more skills is needed to program flight plan, selecting approaches etc. Your most busy times comes when you approach your target airport, get weather and you are cleared to approach. In this situation you need to program right approach into system, brief it to yourself and be all of the time up to date with radio traffic and on course fly the plane. You can practice most of the things in ground but then real thing is to do it in busy conditions in flying airplane. Partial panel is also completely different with glass and steam. In practice difference between Cirrus with Avidyne/GNS430 or Diamond with G1000 is not as big at all. Garmin logic to program flight plans and approaches is very similar in both of these.

Other question is that should you get your IFR training done in some peaceful little city or in busy San Francisco bay airspace.If you like to get it done cheaply and fast, small city flight school may be good choice. If you like to get your skills to level where about no airspace is too busy to you take SF-Bay but remember
that you may not got it done with minimum hours.

Now, i have crossed north American continent twice and passed many big cities Class-B air spaces but i have not yet found as busy as SF-bay area . Some rumors tell that Los Angeles area is even worse but i have not yet had change to try.

Lessons learned. Best is not cheapest and fastest. If you fly glass, take your IR with glass even it costs more. If you plan to fly in busy airspaces get your IR there but you need more hours. If you need split your training to multiple chunks, it causes some penalty, may be 10 hours to get level you where uou were when you left. If you are flying IR in flying club, verify that you have plane and instructor available or you can’t keep your schedule. Be prepared that what ever you try, some factors may ruin your schedule. Prepare your paperwork lot of advance, book appointments to FSDO etc lot of advance. Remember, that if there is something wrong in papers, it may took two months round trip to fix it.

And at last but not least, IFR if fun, i don’t regret that i started . I think that getting training in SF-bay and with glass was right choice but it definately was not fastest or cheapest one.

We started Tuesday 21st waking up early morning and got ourself to airport around 8am morning.It is best time to cross mountains in morning when air is not yet hot and most of cumulonimbuses appear in afternoon. It was once again Karoliina’s turn to fly, we decided to go as VFR via pass thru mountains. In IFR minimum enroute altitude
should be highest point enroute rounded upper thousand feet plus 2000 feet. In VFR is enough not touching terrain. We were uncertain how well Diamond would climb in worm air with three full size adults inside and we decided not to take any rists. We still needed to climb to 12500 ft but Diamond did it without any problems.

First leg and mountain crossing went without any problems in excellent weather. Our first stop was in Farmington, New Mexico (KFMN), elevation 5500ft. This airport had nice FBO with air-conditioned restrooms facilities for flight planning we took tanks full of fuel and planned to go Grand Canyon, KGCN .

The route to Gran canyon was really great scenic route, sceneries familiar to most of us from western movies . First we flew over monument Valley and then over grand canyon. When we arrived Gran Canyon, there was thunderstorm just over airport and we decided to go on.

We landed Kingman, KIGM, elevation 3360ft . That place was like burning hell, temperature around 40 degrees of celsius. We got there in place where was no cover from sun, airport staff advised us that restrooms are in passenger terminal and there was no other
way back to apron expect left someone open to gate and we did not find any flight planning facilities. The place was also graveyard of DHL american fleet.

From Kingman we continued to Lancaster, KWJF, hot but not so hot than Kingman and there was even some wind to make it to feel more comfortable. There was also good facilities air conditioned building to do flight planning. We decided to file IFR plan to Palo Alto via route PMD V197 EHF AVE V137 ROM V485 LICKE and it was Kate’s turn to fly IFR . When we took off, it was evening twilight and soon it was completely dark night but weather was good. I must say that I don’t feel comfortable to fly in night in mountaineus terrain. If engine quits, there is no way to chose good
place for forced landing. In plains, there is good possibility that terrain under is not so bad.

We landed Palo alto 22.56, we had some probems to get taxi and finally got to our motel Standford Motor inn around 1am.I must say that i felt really exhausted, long and hot flight day.

If ypu would like see more pictures, please look our N756DS Picasa callery

We kept Sunday just for resting with our friends, in Chrissi’s and Randi’s place. On Monday morning we checked weather and noticed that there is front with thunder storms moving across our route. We filed IFR plan to Salina (KSLN) via route 1H0 SNYDR V12 OJC V508 TOP V4 ZITIK KSLN but then we saw thunderstorms front of us and decided to land in Topeka (KTOP) to wait front pas us. We waited couple of hours in Topeka FBO weather briefing room and followed from Nexrad thunderstorms moving south east. After thunderstorms passed, we filed IFR plan to Hays (KHYS) via route
V4 SLN V508 KHYS. At beginning of route we needed to fly in rain but still in VMC.

We landed to Hays in perfect VMC conditions and sunny weather but there was big cumulonimbus growing nearby and it looked threatening. We decided togo on as
quickly as possible and now it was Karoliina’s turn to fly. We filed route to Pueblo via V244 but
soon we needed to ask defer from our course because there was really beauty monster, huge thundercloud from our right side. I have never seen same time s beauty but also so threatening thundercloud before. It did not cause a actual danger to us because is was easy to see and avoid. I just looked lightnings sriking from cloud to ground. There was other thunderstorm to go around that just passed Pueblo. We were able to land Pueblo without any problems.

In Pueblo, there was local FBO, Flower Aviation, they booked Hotel to us and arranged transport. We spend night in La Quinta inn after long and challenging flight day.

We had plan to leave Florida as early as possible to avoid bad weather but we were so tired because we did had so much lack of sleep during last few days.
We woke up in Jacksonville Ramada Inn 9 am and arrived with car to Sterling Flight in Craig Municipal airport ( KCRG ) 11 am. There was front of
bad weather arriving from north west. Kate needed to return our rental car to Jacksonville International Airport ( KJAX ) and Karoliina flew N756DS
there. Cloud ceiling was already low and there was moderate precipitation. Kate got rental car return point but there person in Rental car return did not know
how to get General Aviation terminal ( FBO ), she was completely unaware that such thing as general aviation even exists and could only say
that you need to go airliner terminal. Kate finally found FBO by walking and sweating half an hour in the hot Florida weather.

Karoliina arrived the same time
Sheltair FBO. We checked weather and noticed that we need to leave quickly to avoid getting worse weather. After take off from KJAX we were able to climb
to 2000ft . Soo Ceiling started to go lower and we ended to fly below clouds under 1000ft in uncontrolled Airspace over Florida swamps but still
safely within VFR minimums. After half of hour ceiling started to raise and we were in perfect weather for rest of this leg. We arrived safely to our
refueling stop Russel Rome airport ( KRMG ) near by Atlanta.

From KRMG our next leg was to St Louis, Missouri. Ceiling was high and we were able to cruise 4000ft . We used VFR Flight following for both legs
to get warnings about possible severe weather or traffic. That was a easy leg, just put flight plan to G1000 and autopilot on. Our target for
this leg was Creve Couer airport ( 1H0 ) . We arrived there about 9pm just around sunset. The airport is under complex St Louis Class B airspace.
The G1000 was very useful showing all airspace borders and altitude limits. VFR Flight following was also useful when arriving to unfamiliar
complex airspace.

Weather front is just arriving to St Louis

When we landed, Karoliina called our friends Chrissi and Randi, the Cozy Girrrls. They arrived soon with their minivan that had already back seat removed
for carrying things to Oshkosh. We get in to their van and let our Bird to rest for night. Chrissi and Randi are experimental aircraft builders and they
run their own small experimental aircraft parts business CG Products. They do really great work and perfect professional quality parts in
their workshop.

Good night to N756DS for good flight

Our first day, we drove from Miami to Jacksonville, 6 hours via Inter State 95.
Karoliina was using N97 to write mails to our insurance broker. We got all needed work for insurance done just 15 minutes before we arrived to pick up plane from Sterling Flight training.

There the our new Pretty Bird was waiting for us. Just fresh annual done and no
extra repairs needed. We decided to go for test flight with Sterling flight instructor and at the same time get checked out to the plane. First Touch and Go’s in At Augustine ( KSGX ) and then scenery route to Space Coast Regional Airport ( KTIX ).

It would be big sin to go so near of Nasa Cape Caneveral launch site and not even seeing it. Sad that so distant but we have wery tight schedule. Next morning we needed
to fly the plane to St Louis.

In KTIX we switched pilots and it was Karoliina’s turn to fly. She went to St Augustine to do touch and go’s as night flight. We happily landed back to KCRG 10.00 pm. Then it was time to get some sleep in hotel, happy but really very tired.

Karoliina and Kate are in Dysseldorf waiting for connection flight. Very tired. fb

T-0. We are leaving home now and heading to airport. fb

Packing for the USA trip is almost finished. Last bits of housecleaning tasks to be done before leaving to EFHK airport. fb

Aerodynamic Comparison of Hyper-Elliptic Cambered Span (HECS) Wings with Conventional Configurations

http://rcairplanedesign.googlepages.com/Design-BWB-Blended-Wing-Body-RCplane.htm

The mentioned AVL can be found from the following address:
http://web.mit.edu/drela/Public/web/avl/

Inlet Channel for a Ducted Fan Propulsion System of a Light Aircraft – a 300 km/h ultralight aircraft with ducted fan propulsion is discussed

Common errors in ducted fan design
Performance Study of a Ducted Fan System

DFDC

http://morphing.mae.cornell.edu/Papers/%5BManzo%5D%20HECS%20MS%20Thesis%20Master.pdf

http://www.aiaa.org/content.cfm?pageid=406&gTable=mtgpaper&gID=65912

I created a wiki page to katix gforge for link collection.

I hope you like it. It is not sorted in any sense, but it contains lots of interesting links. A friend of mine has been sending these to me a quite long time and I thought that I could share the collection with you.

http://gforge.katix.org/gf/project/twinzygger/wiki/?pagename=MiscTechPapers

New idea:
- A body that comprises of a laminar body and wing blended together
- There is a V-tail in a blended boom
- Rear of the center section has suction slot on top side
- The boom contains a electric fan that is used for suction and additional thrust
- There are two turbocharged Rotax 912UL engines in the wings which are hidden in blended pods that continue the airfoil shape of the wing without interruption
- Both engines turn additional turbochargers which drive generators which generate electricity for the rear fan of the aircraft

Items that need to be studied:
- does pressure thrust work with this kind of shape, or does it require axisymmetric body?
- compare the drag of minimum axisymmetric body with non-blended wings to a blended wing body which has larger cross sectional area, but potentially lower wetted area.
- wing incidence relative to the center section – center section has a lower aspect ratio than the wings and what it requires to achieve optimal lift distribution in this combined case
- the achievable gain from the lack of interference drag or very small interference drag
- optimal wing loading for a combined blended wing body compared to a pod+boom+wings solution
- shark fin shape on the outer wing sections, the gain and the issues

Youtube video about Burt Rutan Ares

I was looking Parson’s high transition length body in a book and thought that maybe if I modify my body shape also so that the nose becomes sharper. By sacrificing some interior space, the flow acceleration can be kept for high transition length according the book I was reading this. My modified body looks like this.

Despite the QFLR5 algorithm is not maybe designed for simulating NLF bodies (it is designed for simulating wings), the pressure distribution looks like the same as the wind tunnel data for the Parson’s body which makes me think that it might not be that much wrong.

I was looking Parson’s high transition length body in a book and thought that maybe if I modify my body shape also so that the nose becomes sharper. By sacrificing some interior space, the flow acceleration can be kept for high transition length according the book I was reading this. My modified body looks like this.

Despite the QFLR5 algorithm is not maybe designed for simulating NLF bodies (it is designed for simulating wings), the pressure distribution looks like the same as the wind tunnel data for the Parson’s body which makes me think that it might not be that much wrong.

Ever wanted a Star Trek’s computer? It is here today:

http://www.wolframalpha.com/

For starters, try out for example: integrate x+y^2
This service is superb.

I have been thinking this topic for quite a long time and my old conclusion was that it is not feasible. However, there is very little information about pressure suits out there, but looking at the very little there is about the old Mercury suits etc., I have got indications that actually fabrication of a partial pressure suit might be feasible. Buying one might not be feasible because of lack of availability and insane pricing.

I would like to learn more about the topic, but in the Internet at least, there is very little or nothing. If someone has some insight, please leave some comments.

A major portion of aircraft drag (in addition to the wing) is generated by the fuselage. The poor aircraft has to drag the draggy fuselage forwards. It is justified to target for reducing the fuselage drag in addition to the drag of the wings to achieve high L/D ratio and thus high efficiency and exceptional miles per gallon figure.

The idea comprises of the following claims:
- a laminar body with optimal fineness ratio for minimum drag
- a tail boom behind the optimal fineness ratio laminar pod
- electric motor (or couple of electric motors in cascade) turn
one or many ducted fans that are in cascade inside the rear of the fuselage.
The fan(s) take their air intake from the boundary layer of the fuselage.
- the fans are driven with batteries on takeoff.
- the fans are driven in cruise with electricity generated from the exhaust gas of the two gasoline engines which are mounted in wings.
- there is an additional turbine mounted in the exhaust that turns a generator rather than compressing air for the gasoline engine.
- the exhaust for the air is either in the tail boom prior to the tail or after the tail, whichever is found to provide best results.
- the fans provide suction for the fuselage boundary layer and also additional thrust for the aircraft. This configuration however, does not cause additional drag for the aircraft but reduces it.
- additional generators can be mounted to wing tip vortices so that the wing tip vortex turns the turbine blades and thus generates electricity for the fans located in the rear of the fuselage.
- the generators, battery charging and fans are computer controlled.
- the fans utilize all power that can be drawn from the exhaust gas and the wing tip turbines and thus runs at full power available to it continuously. On takeoff batteries are used to ensure high centerline thrust for the hypothetical situation where one of the gasoline engines would fail.

A major portion of aircraft drag (in addition to the wing) is generated by the fuselage. The poor aircraft has to drag the draggy fuselage forwards. It is justified to target for reducing the fuselage drag in addition to the drag of the wings to achieve high L/D ratio and thus high efficiency and exceptional miles per gallon figure.

The idea comprises of the following claims:
- a laminar body with optimal fineness ratio for minimum drag
- a tail boom behind the optimal fineness ratio laminar pod
- electric motor (or couple of electric motors in cascade) turn
one or many ducted fans that are in cascade inside the rear of the fuselage.
The fan(s) take their air intake from the boundary layer of the fuselage.
- the fans are driven with batteries on takeoff.
- the fans are driven in cruise with electricity generated from the exhaust gas of the two gasoline engines which are mounted in wings.
- there is an additional turbine mounted in the exhaust that turns a generator rather than compressing air for the gasoline engine.
- the exhaust for the air is either in the tail boom prior to the tail or after the tail, whichever is found to provide best results.
- the fans provide suction for the fuselage boundary layer and also additional thrust for the aircraft. This configuration however, does not cause additional drag for the aircraft but reduces it.
- additional generators can be mounted to wing tip vortices so that the wing tip vortex turns the turbine blades and thus generates electricity for the fans located in the rear of the fuselage.
- the generators, battery charging and fans are computer controlled.
- the fans utilize all power that can be drawn from the exhaust gas and the wing tip turbines and thus runs at full power available to it continuously. On takeoff batteries are used to ensure high centerline thrust for the hypothetical situation where one of the gasoline engines would fail.

I found these some time ago, but now got reminded about it also on one comment to a previous post. Therefore I decided to open a new topic for it:

Goldschmied drag reduction tech papers:
http://cafefoundation.org/v2/pav_enablingtech_dragreduction.php

Interesting reading for anyone interested in achieving major breakthroughs in the fuselage drag.

New iteration of laminar body fuselage shape:

New iteration of laminar body fuselage shape:

One interesting aircraft in the historical data:

Lancair Evolution

P/W Power to weight ratio 7.54 kg/kW, 12.28 lbs/hp.
W/S Wing loading 142 kg/m^2, 29.05 lbs/sqft
Stall speed 61 kts
Empty weight to gross weight ratio: 0.55
Fuel to gross weight ratio: 0.2
Aspect ratio: 10.3

Aircraft with 12.28 lbs/hp power loading and 29.05 lbs/sqft wing loading in other words can
be made to climb, and it can also meet FAR 23 in stall speed requirement (61 kts). According to an article, the LC Evolution demonstrated glide ratio of 1:22 which is amazing compared to the competition, especially achieving this with only AR=10.3.

With these parameters, a smaller Rotax powered twin aircraft would be sized as follows:
Engines: 2 x Rotax 912UL, each turbocharged at 100 hp
Gross weight: 1116 kg
Empty weight: 0.55 * 1116 kg = 613 kg
Fuel weight: 0.2 * 1116 kg = 223 kg
Fuel volume: 314 l
Wing area: 1116 kg / 142 kg/m2 = 7.75 m2
Useful load (including fuel): 503 kg
Useful load full fuel: 280 kg
Endurance: 10.4 hours

Challenges:
- achieving the stall speed of 61 kts, requires very high Clmax for the flapped airfoil
- achieving > 20 glide ratio with lower Re, requires higher AR most likely
- achieving positive climb rate with single engine
- achieve the Clmax with wings that carry two engine pods on them (blanketing potentially flap and part of the wing).
- The fuel potentially does not fit inside the wing of this low wing area.

What it shows:
- Still with this high wing loading, it would be possible to fit three adults on the plane with full fuel. The result is not at all bad compared to any production aircraft.
- Empty weight looks realistic taking in account there are two Rotax engines on the craft. It is higher than it would be if it was relatively as lightweight as a Dynaero.

Bottom line: The parameters of the Lancair Evolution are very impressive and inspiring.

Realism hits:

Reduce the wing loading to 120 kg/m2
Wing area becomes: 1116 kg / 120 kg/m2 = 9.3 m2

-> It ends up in the magic 9.3 m2 wing area I have ended up from many directions already several times before.

I have in our svn by the way a OpenOffice.org spreadsheet about historical data about the basic design parameters for aircraft. There are just couple of aircraft currently in the list, but I will add more later and also you can help, you can send me more lines to the sheet, just take the sheet as a template and fill your lines and send it to me karoliina dot t dot salminen at gmail dot com. I will copy-paste your additions to the table. I am particularly interested in fast composite aircraft and not so interested in the parameters of tube and fabric aircraft or metal aircraft (except interesting ones, like RV). All data even for fabric and tube, is welcome of course, but I wanted to let you know what I am interested in the most.

Here is the spreadsheet in OpenOffice.org format:
WeightAndBasicParametersHistoricalStatistics.ods

Here is the current version of the spreadsheet in PDF-format for quick viewing:
WeightAndBasicParametersHistoricalStatistics.pdf

I decided to do svn up for QFLR5 and was delighted that it has progressed further. I decided to try out fuselage shapes this time because it turned out that QFLR5 now allows larger airfoil thicknesses than 20%. Therefore here is a 26% fuselage shape I created today.

Here is how I started it:
1. I took NLF414F airfoil which I know to have very low drag value at 10 million reynolds number.
2. I decambered to it to zero camber
3. I changed thickness to 26%
4. I changed leading edge radius: 30% from leading edge, 0.8 ratio.

The simulation result gives very low Cd-value. The problem in reality is that because of all intersections, and a hatch where one has to enter the craft, the transition point is not that great as predicted by the program most likely.

Here is another simulation, transition forced at 40% chord. The Reynolds number is the same, 41 million with mach 0.29:

I further adjusted the leading edge radius, from the above, I reduced it to 0.8 again.

Here is the result KSNLFFUSELAGE3:

The simulated polar for the NLFFUSELAGE3:

Obviously the fuselage is supposed to be flown at zero angle of attack on cruise flight, but for slight side slip situations it is good to know how the drag rises on the fuselage. It also affects to the stability negatively (for example because the lift slope is not at all linear).

Potential improvement idea for use in non-steady flight: widen the low drag bucket a bit.

The airfoil shape as a axisymmetric fuselage (or as a generic pod, this works also as a engine pod), 3D illustration:

And this is how it looks from inside:

Structurally the pod requires thicker boom than the optimum and unfortunately the drag will be larger than the simulated one for the pod alone.

I decided to do svn up for QFLR5 and was delighted that it has progressed further. I decided to try out fuselage shapes this time because it turned out that QFLR5 now allows larger airfoil thicknesses than 20%. Therefore here is a 26% fuselage shape I created today.

Here is how I started it:
1. I took NLF414F airfoil which I know to have very low drag value at 10 million reynolds number.
2. I decambered to it to zero camber
3. I changed thickness to 26%
4. I changed leading edge radius: 30% from leading edge, 0.8 ratio.

The simulation result gives very low Cd-value. The problem in reality is that because of all intersections, and a hatch where one has to enter the craft, the transition point is not that great as predicted by the program most likely.

Here is another simulation, transition forced at 40% chord. The Reynolds number is the same, 41 million with mach 0.29:

I further adjusted the leading edge radius, from the above, I reduced it to 0.8 again.

Here is the result KSNLFFUSELAGE3:

The simulated polar for the NLFFUSELAGE3:

Obviously the fuselage is supposed to be flown at zero angle of attack on cruise flight, but for slight side slip situations it is good to know how the drag rises on the fuselage. It also affects to the stability negatively (for example because the lift slope is not at all linear).

Potential improvement idea for use in non-steady flight: widen the low drag bucket a bit.

The airfoil shape as a axisymmetric fuselage (or as a generic pod, this works also as a engine pod), 3D illustration:

And this is how it looks from inside:

Structurally the pod requires thicker boom than the optimum and unfortunately the drag will be larger than the simulated one for the pod alone.

Malmin ilmailukerho (MIK) jarjestaa Malmilla SIL-luokassa 5.5.2009 aiheena lentokoneen aerodynaaminen suunnittelu. Luennoitsijana Juha Karjalainen TKK:lta. Blogin lukijat ovat lampimasti tervetulleita Malmin Ilmailukerhon jasenten lisaksi. Kieli: suomi. Tilaisuuteen on vapaa paasy.

In English: There is a lecture about aerodynamics arranged at Malmi SIL class 5th May 2009. The language in the lecture is Finnish and the lecturer is going to be Juha Karjalainen from Helsinki University of Technology.

Here is a preview version of a song I started today:

Mechanical Life Form – preview

This is not the final mix or may not have all the elements I might want to add and I may play again some parts which were poorly played. However, here is the preview. All comments are very welcome.