APS/Ω Gas turbine bike build

[fredvance]

Anders, look at the front view. I think the air would stay attached from windshield to helmet. I see shoulders, hands, and legs, not good. I agree moving the foot pegs back and down would be good. The tail could be longer and lower. Open at the back is probably better. Just my opinion.

[MattGuzzetta]

Anders, you just keep on, love it!  A big part of making the aerodynamics work better for you is what rules do you have to follow?  Frontal area is important, but the flow of air over the bike is very important.  The normal motorcycle rules for fairing use seems to me to be about not having enough side area that can be affected by side winds. The side photo shows no streamlining on the bike on the main body.  If we can get you protected from the wind, you can probably go a lot faster with the motor you now have. It depends on how much air you need for the motor for intake and cooling.  If the air can be "managed" around all the bits and pieces that make up the bike, you can probably gain 40-50 KPH without adding more horsepower. 
Too bad we are so far away, this would be a fun project!  If there is anyway I can help you, just let me know.   I know glass work is something you hate, and I also agree, but it is a fantastic way to make complex shapes quickly.  It can be a lot easier than you think, you just need some help and encouragement to make it happen!   I have a love hate relationship with composites, love what you can do with it and hate to have to work with it!
Let me know if you would like some long distance help and we can see what happens.  No fee needed, just like to help someone who is such a great enthusiast and craftsman.
Matt Guzzetta
Here are a couple of duct parts made with foam and fiberglass that shows you can make things
with this material and process that would be very difficult by other methods. The shroud covering
the motor is fiberglass over pattern wax that was molded on the motor, very efficient at cooling
the motor.

[tauruck]

Anders, make another Aluminium tail piece and hold it in place with double sided tape.
Shape a new section with foam and cover that with glass.

You can do back to back testing with both tails.

I think I will do the extended tail as a learning project in sheet aluminum to get a chance to learn more about it.

I despise glass fiber, a material that cannot be welded cannot be trusted either.

Do not fear glass Anders!!!! I too once lived in the dark ages with regard to glass. You can actually weld it with epoxy. It is a very forgiving material to work in. There isn't as much voodoo in it as I had ever heard.

You have the talent and knack to pick it up, I have seen your work. Once you learn how to work with it and become comfortable with it you will embrace its ease of use. Those hard to shape and time consuming pieces become a breeze with glass.

Trust me, I am a complete convert. The stuff is ridiculously strong and resilient too when a proper schedule is used. The new epoxy resins require little if any ventilation and have zero smell. You can layup parts in your living room if you wanted!

With the 3D printer you can make molds too....I promise, try it on something small and you will be disappointed you waited so long to use the stuff.

Anders, you already worked with fibreglass  on shaping your body work!!!!. I guess the itching got to you.
Goes with the territory. 

[sofadriver]

Anders, look at the front view. I think the air would stay attached from windshield to helmet. I see shoulders, hands, and legs, not good. I agree moving the foot pegs back and down would be good. The tail could be longer and lower. Open at the back is probably better. Just my opinion.

I agree with all.

Anders try this to measure your frontal area.  Put a piece of cardboard against the garage door. Put the tail of your bike against it pointing down the driveway.  Wait until dark then park your car 150' away and aimed at the bike.  Turn on the bright lights and cover one headlight.  Trace the bike's shadow on the cardboard.  Obviously you'll need a helper if you want to see the total area with rider.  Worked good for me! 

[tauruck]

You're a very clever kid Mike.

[wobblywalrus]

Anders, your feet might be as far back as they can go.  Don't forget about the exhaust pipe opening!

[Mobacken Racing]

Anders, look at the front view. I think the air would stay attached from windshield to helmet. I see shoulders, hands, and legs, not good. I agree moving the foot pegs back and down would be good. The tail could be longer and lower. Open at the back is probably better. Just my opinion.

Hi Fred,

Could you explain what you mean with that the air would stay attached, I don´t understand the term.

The shoulders I cannot do much about without completely altering the fairings, the handlebars can possibly be shortened a bit and I still have the knee sliding pucks fitted to the leathers so removing them will hide the knees much better.

An experimental tail extension will be built so I can test all different tail configurations, I plan to buy a planishing hammer as a christmas gift for myself but keep quiet about it since I don´t want to spoil the surprise.

Cheers!
/Anders

[Mobacken Racing]

Anders, you just keep on, love it!  A big part of making the aerodynamics work better for you is what rules do you have to follow?  Frontal area is important, but the flow of air over the bike is very important.  The normal motorcycle rules for fairing use seems to me to be about not having enough side area that can be affected by side winds. The side photo shows no streamlining on the bike on the main body.  If we can get you protected from the wind, you can probably go a lot faster with the motor you now have. It depends on how much air you need for the motor for intake and cooling.  If the air can be "managed" around all the bits and pieces that make up the bike, you can probably gain 40-50 KPH without adding more horsepower. 
Too bad we are so far away, this would be a fun project!  If there is anyway I can help you, just let me know.   I know glass work is something you hate, and I also agree, but it is a fantastic way to make complex shapes quickly.  It can be a lot easier than you think, you just need some help and encouragement to make it happen!   I have a love hate relationship with composites, love what you can do with it and hate to have to work with it!
Let me know if you would like some long distance help and we can see what happens.  No fee needed, just like to help someone who is such a great enthusiast and craftsman.
Matt Guzzetta
Here are a couple of duct parts made with foam and fiberglass that shows you can make things
with this material and process that would be very difficult by other methods. The shroud covering
the motor is fiberglass over pattern wax that was molded on the motor, very efficient at cooling
the motor.

Hi Matt!

Making side panels for the front fairings is on my to-do list, I could quite easily make extensions from the existing fairings and fit a coulple of fixing points on the frame for them.

The engine consumes a little over 1 kubic meter of air per second, and the new engine I am designing will need twice that so a big consideration when building the fairings is how to get enough air into the engine intake.

I really like the glass fiber ducts you posted pictures of, a pair of those up front directing air past the dashboard wiring and into the air intake would be great. The mesh covered "head light" hole won´t do much good since the air passing through it blows straight at the crow nest of wires behind the gauges.

Chatting about this is the best help I can get, I prefer to build things by myself but encouragement like this is much appreciated.

Cheers!
/Anders

[Mobacken Racing]

I agree with all.

Anders try this to measure your frontal area.  Put a piece of cardboard against the garage door. Put the tail of your bike against it pointing down the driveway.  Wait until dark then park your car 150' away and aimed at the bike.  Turn on the bright lights and cover one headlight.  Trace the bike's shadow on the cardboard.  Obviously you'll need a helper if you want to see the total area with rider.  Worked good for me! 

That is a very clever idea!

[generatorshovel]

Anders, look at the front view. I think the air would stay attached from windshield to helmet. I see shoulders, hands, and legs, not good. I agree moving the foot pegs back and down would be good. The tail could be longer and lower. Open at the back is probably better. Just my opinion.

Hi Fred,

Could you explain what you mean with that the air would stay attached, I don´t understand the term.

https://youtu.be/TqTSyFz6DJc
Fred is still asleep Anders, lol

[Mobacken Racing]

https://youtu.be/TqTSyFz6DJc
Fred is still asleep Anders, lol

So it is a good thing then, that the air stays attached between windshield to helmet?

[fredvance]

Anders sorry it took me so long to get back to you. I am not sure about some of the termonology. My understanding of ATTACHED is that it is a good thing. in the case of your upper fairing and helmet I think the air would continue a smooth flow. If you were farther back or in such a position that the air would not have a continous flow it would seperate, not a good thing.

[bbarn]

https://youtu.be/TqTSyFz6DJc
Fred is still asleep Anders, lol

So it is a good thing then, that the air stays attached between windshield to helmet?

Yes. Keeping the air attached and as free from turbulence as possible = reduced aero drag. Obviously less drag means more power being applied to increase velocity and not wasting it just to overcome the drag you are creating.

The less you disturb the air the better. If you have to disturb it, try to control it so that it limits the amount of drag it generates. Keeping it "attached" means you are providing a path of least resistance for the air to move around/over/through a shape.

For visual purposes use the picture below. Laminar flow is what you want. You will never get it to look like that, but you want to strive to be as close as possible to it as you can. Let's assume that the flow over the front fairing is laminar. When it leaves that area what will happen to it? It looks like it should flow nicely right onto the helmet by jumping off the windscreen and "attaching" back onto your helmet staying relatively laminar.

If you look at the picture below, the further the "jump" the air has to make or the less controlled it is when leaving the surface it becomes more like the flow on the right side of the illustration. Your job as the chief aerodynamicist is to try and get as much of the air to move like the left side of the picture!

If you start thinking in terms of how to achieve the maximum laminar flow (keeping the air "attached") you will have one portion of your aerodynamic drag reduction completed.



Separation drag is another area to consider. In my comment a while ago about not having a blunt fender I was referring to separation drag. This happens when you lose control of the air and it goes turbulent creating a vacuum. This effect can be used to advantage to make down force but that typically happens in a horizontal plane.

Making it in the vertical plane (Stubby/blunt endings) generate a vacuum that causes noting but pure drag. You want to avoid this too.



All of this information is rudimentary and not given to you to change your mind or say I am an expert. Every aero problem is unique and solving one leads to another. I am NOT a bike guy. Driven them, raced them on dirt...not a high speed racer. There are things you can do on a bike that will help the aero but MAY make the bike unstable and unable to be ridden. Listen to the advice of the bike guys here.

More free info - Do with it what you like...no charge!

[Seldom Seen Slim]

If I were in the position you're in, Anders, I'd get in touch with Pork Pie.  He's an aero specialist (as well as a damned good photographer) and might be able to give you some tips and help.  He lives in Heilbron, Germany, by the way, so I have no clue what language you'll share

Best wishes and have fun with the bike.

[stay`tee]

Another method for finding Frontal Area. Complete with battle dress (leathers and helmet) sit in the tuck position on your bike,, have a friend using a dress makers tape measure around the extremities as viewed from the front,, this will give a "circumferance", do the maths,,, 

 Anders, Enjoying your journey mate,