Most pec...bizarre aerodynamics thread.

[AR3-GP]

[organic]

http://www.racecar-engineering.com/wp-c ... uppess.jpg

Trying to use the tubercle effect?

[vorticism]

iirc adding these bulbs allowed them to alter the gurney flap shape, which had to be there by regulation.

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Tsukuba earlier this year:
http://www.speedhunters.com/2023/02/att ... than-ever/

[vorticism]

[Big Tea]

https://i.pinimg.com/originals/67/ad/9d ... d88cbe.jpg

Airbus MK1 with improved air-con

[Stu]

With EV’s there are a couple of obvious ways to create a charging effect on the vehicle; firstly solar panels fitted to the roof, the second (probably fairly radical idea) is to use through-flow ducts with turbine GU’s located in the duct exit. Never seen the second option but (to me, at least) seems an obvious thing to do.

[AR3-GP]

With EV’s there are a couple of obvious ways to create a charging effect on the vehicle; firstly solar panels fitted to the roof, the second (probably fairly radical idea) is to use through-flow ducts with turbine GU’s located in the duct exit. Never seen the second option but (to me, at least) seems an obvious thing to do.

Is that particularly efficient? There's no "free energy". Your just taking back what you put in via the motor with an efficiency penalty at the turbine wing tips, rotational friction, and the mass associated with the turbine and supporting architecture.

If you want to recover energy, it's much more efficient to just use the regenerative braking. If you want to supply power to the guest on board, then again you should just supply directly from the high voltage battery.

[Just_a_fan]

With EV’s there are a couple of obvious ways to create a charging effect on the vehicle; firstly solar panels fitted to the roof, the second (probably fairly radical idea) is to use through-flow ducts with turbine GU’s located in the duct exit. Never seen the second option but (to me, at least) seems an obvious thing to do.

The second option just adds a bunch of losses. Just take energy direct from the battery. Taking it from the air stream means you have to accelerate the car (losses) and then generate electricity from the air stream (drag and system losses). Unless you've found a way to get around the laws of physics, of course.

[Stu]

The logic that I am following with that idea is that you are moving the car anyway, small brushless generators have very low friction drag; just looking at methods to extend vehicle range without increasing battery capacity.

Mass management is a critical element for E-CV’s (and that is the area that I work in).

[vorticism]

Is that particularly efficient? There's no "free energy". Your just taking back what you put in via the motor with an efficiency penalty at the turbine wing tips, rotational friction, and the mass associated with the turbine and supporting architecture.

If the duct reduces form drag then hypothetically:
Car without duct: 300 miles
Car with duct: 310 miles
Car with fan in said duct: 305 miles

[Paul G]

Gurney Eagle was a unique Indycar design. Was competitive at Indy but ran a stock block engine which led to some reliability issues.

[Zynerji]

The logic that I am following with that idea is that you are moving the car anyway, small brushless generators have very low friction drag; just looking at methods to extend vehicle range without increasing battery capacity.

Mass management is a critical element for E-CV’s (and that is the area that I work in).

Scoops that are flush with the body, but pop open under braking could be a thing. Even better if it's channeled into the upper diffusor deck..

[Just_a_fan]

The logic that I am following with that idea is that you are moving the car anyway, small brushless generators have very low friction drag; just looking at methods to extend vehicle range without increasing battery capacity.

Mass management is a critical element for E-CV’s (and that is the area that I work in).

But the energy you "get" from those turbine-driven generators ultimately comes from the battery in the first place. And no matter how low friction the generators are, all of the energy recouped plus the losses to drag, etc., all comes from the battery. You get better range by reducing drag and friction and by reducing mass where possible (adding your turbines adds mass that has to be accelerated by the battery meaning, you've guessed it, more wasted energy).

[Farnborough]

The logic that I am following with that idea is that you are moving the car anyway, small brushless generators have very low friction drag; just looking at methods to extend vehicle range without increasing battery capacity.

Mass management is a critical element for E-CV’s (and that is the area that I work in).

But the energy you "get" from those turbine-driven generators ultimately comes from the battery in the first place. And no matter how low friction the generators are, all of the energy recouped plus the losses to drag, etc., all comes from the battery. You get better range by reducing drag and friction and by reducing mass where possible (adding your turbines adds mass that has to be accelerated by the battery meaning, you've guessed it, more wasted energy).

The current RB giving very good quantification of drag efficiency vis à vis the rest of teams.

[Vanja #66]

The logic that I am following with that idea is that you are moving the car anyway, small brushless generators have very low friction drag; just looking at methods to extend vehicle range without increasing battery capacity.

Mass management is a critical element for E-CV’s (and that is the area that I work in).

As Just a fan said, all you get is lots of losses (big and small). External turbine generates drag (especially a small-diameter one with lots of blades), so you need more power for extra drag and extra losses.

Aircraft would be capable of recovering gravitational potential energy when descending, but this isn't available to road vehicles.