Solar car Aerodynamic Analysis

[OSU_SVT]

Hello everyone!

I am part of the Oregon State Solar Vehicle Team. We are
designing our second generation solar car, for the North
American, and World Solar challenge. We already have the
frame and drive systems, and have a 'almost' finished
body design.

However, I believe that the body for our solar car is
the most important part of the WHOLE car. If the body isn't good enough, then the whole car will fail. Of
course, no matter how long you spend, the body will
never be perfect. We just need to get it to a point
thats good ENOUGH.

To that extent, we have gained access to a server farm
and a Fluent expert from HP (The computer company) as a
sponsorship. The expert we are working with has
performed analysis that were accurate to within 10% of
real results, so we trust the results she gives us.

However, the analysis she runs take quite a looooong
time to complete. We cant have her spend too much time
on our project. So for that reason, we are using
Solidworks Flow Simulation to get rough ideas as to if
one design is better then another, before we give the
model to her to test.

Anyways, enough of the history! Our model is still experiencing excessive lift, and the force required to
drive our model forward is on the verge of
sustainability when compared to the expected output of
our solar cells.

We are still not completely sure if we are using Flow
Works correctly. Actually, im sure we are not The
reason for this is because we are still trying to figure
out how to incorporate a ground plane into the
simulation. Im know that the ground plane is very important, as our current simulations doesn't give us
any idea as to the interaction between the cars body and
the ground.

So, any help/advice etc would be extremely useful. Here
are the current stats/settings we are using.

-Solidworks 2009.
-The car is set on a giant rectagle, which is the
'ground'
-The computation domain is set to .03 m below the
surface of the ground.
-The top surface of the ground has the boundary conditions of "real wall" and is set to have a velocity
the car is going.
-The initial settings are: -25 m/s along the positive Z
axis, Surface roughness of 30 Micrometers, the study is
set to an external study, excluding internal volumes,
and the other option is checked as well (Cant remember
what it is), And the initial mesh is set as high as
possible.
-The goals for the study are simply Global Force, and
Global force in the X, Y, and Z. We take the Global
force, and multiply it by the velocity, to get the
predicted power consumption in Watts.

So, I would post photos, but the upload thing here is
not working for some reason... so I cant just provide screen shots of my settings, setups, etc. However, here
are photos from our website where photos of the newest
car design is posted: http://oregonstate.edu/groups/solar/node/95

If you have experience in aerodynamic analysis using
Solidworks 2009, please let me know your advice! If you
can take Solidworks Models (Perhaps parasolids) and run
it through your own fluids programs, perhaps we can do
that.

Please let me know!

Mike

 

[Jbiplane777]

Hi Mike

I can help to solve your problem.
In my uni I have all main CFD-codes running on Pcs and if problem is huge rather powerfull supercomputer+ Ansys CFX.

Yours

Valery Rutkovskiy
Head eSmartDATA
Siberian Federal University
Krasnoyarsk
Russia
[email protected]

 

[Guest]

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