Let me give you guys some information on the sprint car test since I didn't think it would generate questions. We are not currently testing sprint cars but I have been contacted but several World of Outlaw teams that want to perform wind tunnel testing because the tracks change so much even between a session they know that there are too many variable to track comparing one change to another. They feel it is very expensive to track test with the cost of fuel, tires, logistics and feel they would get more information for their $$ in a controlled environment to see what changes help or hurt their performance in a shorter amount of time.
(Gary Eaker & Myself) are currently in the middle of a study for the sprint cars to see if A2 is a good candidate for them and will provide data with a high confidant level. The problem we run into is the top wing is in close proximity to the ceiling and we want to know if and in what way that could be affecting the readings for the sprints. For the first round of testing I used a mini-sprint because the chassis and wing arrangement is very close to a full size sprint car but it is much smaller in size. In the video you might notice that I instrumented the car with a pitot tube (front) and there is also a black strip on the center of the top wing and off to the left side of the suction side (bottom side) of the top wing. These black strips have pressure (7) ports that I will monitor the pressures on both sides of the wing along with the reference pitot tube in the wind tunnel and then we will instrument the car and take it to test on the track. To make a long story short, we will compare many factors (wing angel/height ect..) and pressure readings from the wind tunnel and out on the track (unbounded condition), even CFD to see if and how the wing is affected in close proximity. At A2 we want to provide data that we feel is valid and useful for our customers. I have had many sprint car teams want to test here and get what ever data they get, but we do not feel comfortable giving them data that we don’t fully understand or have some level of confidence and to this point have turned them away. When this study is finished we will know if a sprint car can get some good information in A2 or if they performed scale model testing (such as a mini-sprint) if the #’s look like they are in the right direction and magnitude.
Remember the A2 tunnel doesn't test in Yaw and these guys ( sprints) are more or less going sideways most of the time, at least on really short tracks. Think what the vortices and flow patterns might be then! I think the A2 flow is 85mph.
Huh
I thought I saw yaw on the very first youtube vid
G
Yaw is very important for the sprint cars and on the mini-sprint we did acquire data at several yaw positions. A2 doesn’t yaw full scale cars, but we can manually yaw smaller things such as the mini-sprint and motorcycles (most of the time). And yes, full speed is 85 mph in A2 with smoke testing done at 45 mph.
AeroDyn (our other tunnel) in the first video does have automated yaw along with spinning wheels, automated ride height system and 130 mph test speed.
