11-05-2012, 09:54 AM
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#26
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Diamond Member
Join Date: Sep 2010
Location: NH
Posts: 3,293
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Quote:
Originally Posted by Saylick
I read an article in Pop Sci about this baby, and it shed some light on some of the design reasons behind why the DeltaWing looks and behaves the way it does.
To answer the question about what Ben was explaining as to why it can still corner, it has to do with the following:
Consider this. Have you ever watched Alonso throw his F1 cars into corners? If so, then perhaps you will see where I am going with this. Whenever a car turns, there is a weight transfer towards the outward side of the vehicle. For vehicles with 4 wheels, the majority of the weight will be supported with the outer front tire and the outer rear tire. Conversely, the inside wheels will be carrying minimal load. This is why cars flip over if they try to turn at high enough speeds without a significant amount of force keeping them glued to the ground. The DeltaWing has its front wheels close to each other, which ensures that even if there is a load transfer, because the wheels are so close, the difference in load between the two wheels would be kept low. Couple this with the fact that the Wing's rear end is highly stable and you realize that there is no way in hell that the front end would ever come off the ground. In addition, the majority of the mass of the vehicle is in the rear, and when combined with a long nose (Yes, I get it. It looks like a penis), the result is akin to turning a sledgehammer. Trying to turn a sledgehammer by swinging it is difficult but if you lay it flat on a table and push the handle, you will find that it rotates extremely easily. That push on the handle is the same as the turning force generated by the front wheels. Now you see that it takes not a whole lot of effort to get the vehicle moving in any direction you'd like, and this is what Ben was talking about when he said the front tires are used very efficiently. The front tires job in the Wing is mostly turning since the rear does most of the braking).
As for "heave" and "roll", think of a ship out in water. Heaving is the up and down motion of the boat, while roll is the side to side motion (which makes people sea sick). In describing rear suspension of the Wing, Ben states that the damping in the heave direction (up and down) is typical of race cars but the damping in the roll direction (side to side) is much stiffer since the rear does most of the supporting of the vehicle (in both weight and in keeping the car from flipping over). That's why he mentioned the whole "monkey motion" portion of the rear suspension; it's a peculiar set up that allows the vehicle to use a conventional shock and spring to control heave but to use a stiff bar to control roll.
I can upload the images of the Pop Sci article if you guys want to give it a read. It goes over how Ben started with the idea and explains some of the reasoning behind the design.
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I have to point this out again... a narrow axle track INCREASES weight transfer. The reason there is little weight transfer in the Delta Wing's front axle is because of the disparity in roll stiffness between the front and rear axles (namely the rear is considerably stiffer) and because there isn't much weight on the front wheels in the first place. I'll do the math again on this one if I have to...
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2009 Mazdaspeed3 - DD
1991 Turbo Miata - Toy
Experience is knowing you were an idiot. Common sense is trying not be an idiot. Wisdom is knowing that you will still be an idiot.
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