Hi Guys,

For a college project I am testing the affect aerodyanmic devices have on a saloon car model.

To analyse the affect ride height and aero devices have on the model i am using gobal and surface goal plots to record the levels of lift/downforce. The testing so far is going well, however i have a few questions for the users more experienced with flow simualtion than me.

Firstly, as mentioned, i am currently using surface goals to measure the downforce or lift generated from certain ride heights/ aerodyanmic devices. The surface plot values do chnage slightly when the car is lowered, however i dont think the values are correct. I have also selected surface plots on the aero devices they seem to  be producing a realistic downforce value.

However, the aero devices ( the added parts into the assembly) arent interacting with the surface goal plots at the wheels. Is it possible to get the spoiler and splitter to interact with the car model created, so that i can then detect the increase in downforce at the surface plots located on the wheels. I have mated the parts, but maybe there is an advanced mate that is needed ?

What is the correct way to test the downforce of the model ? Thanks

Secondly, im not able to simulate roating wheels. I saw a guide on the internet where you have to produce a solid extrusion over the wheel and make sure that this wasnt merged. However i wasnt able to select the extrusion seperately. I have a feeling a certain modification was missed out from the guide or i have mis-understood so was wondering whether someone could point me in the right direction to simulate wheel rotation.

Lastly, to calculate the drag generated i was using a global goal in the the direction of flow over the model. This was working and was producing around 600N of drag. This value was deemed to be around usual for the model and the drag coefficient also seems to be correct. However after my modifications, i re-ran a test and the model is now supposedly producing around 1800000 N of drag which is obviously very wrong regardless of the modification. I cant figure out what would cause this reading. I have re-ran several tests and still get this value, all of the other goals are fine.

Any help/ ideas would be appreciated

Many thanks, Guy