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jp-w
Posts: 3
Registered: ‎05-09-2013

Simulation of a CO2 driven Racing Car

205 Views, 4 Replies
05-10-2013 06:25 AM
Hi,
i am new in this Forum, so i hope i'll do right.
I am using Autodesk Simulation CFD for about 2 weeks for the F1 in Schools competition. There for i have to simulate a Racing Car, which ist driven by the blow back of a bottle with compressed CO2. I alredy setted boundary conditions for the main flow (Inlett : 1866 l/s Outlett : 0 Pa) and the spinning wheels (Rotation : 14640 rpm). Now i want to sett the output of the CO2 bolttle. I tried to sett the outlett as a volumetric flow, but when i start the Simulation, it will be ignored. (Instead of CO2 im using Air, because Sim. CFD can't work with two fluids)
Unfortunately i can't just leave it out, because it is important for the aerodynamics. What do you think is the best way to simulate this, or what did i do wrong. Would be great if you could help me.
Jp
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wildej
Posts: 937
Registered: ‎08-25-2011

Re: Simulation of a CO2 driven Racing Car

05-11-2013 12:21 AM in reply to: jp-w

Be sure that you are not creating an internal Boundary Condition (BC).

The BC needs to be on the boundary/the edge of the domain or attached to a suppressed part, which is essentially the boundary again. Try suppressing whatever you are attaching it to and you should be OK.

In fact, you can suppress all solid parts from the mesh - you can still show them all in the results,

 

You could also look into running scalars, here you could even see where the CO2 goes vs the clean air passing over the car.



Jon Wilde
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Member
jp-w
Posts: 3
Registered: ‎05-09-2013

Re: Simulation of a CO2 driven Racing Car

05-12-2013 01:24 PM in reply to: wildej

Ok, Thanks

I tried it out, but when I am suppressing the fluid volume at the output of the "bottle" , Sim. CFD will ignore the BC for the main Flow.(?)

Jp

 

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Product Support
wildej
Posts: 937
Registered: ‎08-25-2011

Re: Simulation of a CO2 driven Racing Car

05-12-2013 11:58 PM in reply to: jp-w

Hi Jp,

 

Without seeing the model this is quite difficult. Is it perhaps because you are now suppressing the entire fluid domain also?

 

Or maybe because the scale of the results only shows the effect of just one of the inlets?

If you hold 'shift' and float your mouse over a cut-plane that is showing velocity magnitude, do you only have zero velocities?



Jon Wilde
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Member
jp-w
Posts: 3
Registered: ‎05-09-2013

Re: Simulation of a CO2 driven Racing Car

05-16-2013 12:04 PM in reply to: jp-w
Sorry, that i haven't answerd jet.
The main Volume is not suppressed.
(When i am suppressing both air Volumens the results show some strange faces)
I had a look at the velocity and ther are mostly positiv values.
Would it be helpfull to post a screenshot ?
Where can i switch visibility of effects on and off? Because with the compressed volume (like recommented) the second inlett is listed in the report, but not shown in the results.
Jp
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