[ODE] [off-topic] Modelling aerodynamics

[Henri Hakl]

I don't see why you'd want to make your life unnecessarily complex; a force
acting (relatively) downwards based on the velocity of the car. Should not
be a problem?

----- Original Message -----
From: "Thomas Harte" <thomasharte@lycos.co.uk>
To: <ode@q12.org>
Sent: Sunday, December 08, 2002 5:49 PM
Subject: [ODE] [off-topic] Modelling aerodynamics


> I ask these questions here because a lot of clever physics people seem to
read
> this list, and I can't find a more specific alt.clever.physicians or
whatever.
>
> I, like many before me, am seeing my ODE simulated vehicles flip (think
handbrake)
> and roll unrealistically often. So I've done some reading, and come across
> numerous references to the way that real cars use downforce to solve this
> problem. Therefore I wish to implement aerodynamics in my simulation -
which I
> know ODE will not help with - and see if that helps me at all.
>
> Unfortunately I'm a bit dense about this sort of thing, and can't find any
> references. Naturally I want my game to execute in real time, and it is
really only
> interested in cars, so the following ideas have occurred to me :
>
> - assume that vehicle only generates downforce when travelling forwards.
Assume
> that the car will really only usually travel forwards, and simply apply a
downward
> force that is in some way a function of body velocity
>
> - slight modification of above, make downward force a function of velocity
and a
> very simple function of orientation (probably just a dot product between
the
> direction a car would normally consider to be forwards and the direction
in which it
> is travelling)
>
> - use an approximate model of air flow. Simulate, say, 20 well spaced air
particles
> colliding with object over every time step (modelled using near-enough
correct
> maths), and use these to make assertions about generated downforce.
>
> Are these practical ideas? What do other people do?
>
> -Thomas
>
> Free Email at http://www.lycos.co.uk
>
>