Designing and Building my own High MPG Car

[Smurf]

Freebeard, just to clarify.. That SketchUp of the three shapes, the one on the right side is considered "acceptable"? For example, if one were to build a reverse trike roughly using that shape, and an aircraft canopy slapped on the top, they would be ok?

[GoGogebic]

The wheel fairings are definitively not a done deal.

The suspension's cross sectional area is much less than a fairing that would enclose all the members. So even if I left the a-arms made out round tube. The total drag would be around the same. But I am planning on enclosing the tubes with airfoil shaped plastics.

[HydroJim]

Here is a design I made. I had it all figured out. That was until I figured out that my minimum wage part time job wasn't going to support the project.

Almost perfect aerodynamic shape. I personally would keep it 3 wheeled, but I do understand your reasons for 4 wheels. It could be made shorter, by reclining the seat, but this would make it longer.

[freebeard]

Smurf -- I created it for this thread, to raise that question. It ran three pages but it ends up discussing the Volkhart-Sagitta. For various reasons, in ground effect I think you want a triangular cross-section, like the ME-262.

GoGogebic -- Search on 'interference drag'. There's different aspects to drag; form drag, skin friction, &etc. It's why biplanes can't have their wings too close together. In this case turbulence caused by the main body, the inner side of the pontoon and the individual suspension and drive components interacts. There's others who could state it more authoritatively than me, aerohead for instance, but the original research goes back to GMs wind tunnels.

Or you could declare the point irrelevant; that's what they do with Formula 1 race cars (fast but dirty aerodynamically). You might notice the car design in my profile picture uses airfoil section torsion bar hourings.

Here's a pontoon fender that is like yours in the back half. Frank Lockhart's Stutz Blackhawk:


One of the problems with off-road racing motorcycles is that they aren't a stable platform for lighting. With the lights in the fenders, they point with the wheels, which is good, but on a rough surface, shadows will be bouncing around. Consider a center headlight too, like that Tucker.

[GoGogebic]

I really like the above design. When it comes to aerodynamics my trust lies in a book by Joseph Katz called racecar aerodynamics.

The front wheel fairings will not move. I just haven't figured out how to attach them to the body yet. I have modeled plenty of ideas but none were pretty enough.

[freebeard]

That's a recreation of the original Blackhawk. It's kind of a sad story.

[GoGogebic]

Has anyone with an Honda insight ever tried using the engine to recharge the battery.

If you were cruising at 65mph and then kicked on the Integrated Motor Assist and opened the engine throttle both at the same time to maintain 65mph while charging the battery. Then after a few secs kill the motor and use the IMA to power the wheels for a few seconds to maintain 65mph. This would be a form of automated Pulse and Glide but much safer and of course less efficient.

Now thinking bigger picture replace the IMA with something like Williams f1 flywheel hybrid system. almost 100% efficiency is an awesome concept.

[freebeard]

It's your thread and all; but weren't we talking about a 28hp 250cc twin/6-spd w/ LSD?

[GoGogebic]

Yeah, I want to use that engine and add fly by wire and a Integrated Motor Assist device that I can use to automate pulse and glide

[freebeard]

Insight-like, then?

You know, we're not that far apart in our thinking. Here is my design. Where you start with F1/Grand Prix paradigm, I start with "what could you do with an old Beetle"?


The similarities? Bubble canopy, Trophenwagen tail and open wheels. With the fat Beetle body the inside contours of the pontoons mimic the concave shape of the body. The outer face follows the Aerodynamic Template. It doesn't show well in the sketch, but the 'ridge' of the fender runs inside to outside in the front and outside to inside in the rear. The rear pontoons would be almost twice as long as the fronts.