The fluid dynamic characteristics of a golf ball are to be tested using a model in a wind tunnel. Dependent parameters are the drag force, Fo, and lift, F, on the hall. The independent parameters include diameter D, airspeed V, angular speed, a, dimple depth, d'and air properties. The dimensionless parameters are as follows: PVD aD d F pV2 D F pVD oD d H V D and D pVD " A golf pro can hit a ball at P-60m's and 6000rpm. To model these conditions in a wind tunnel with maximum speed of 30m/s, what diameter model should be used? What dimple depth should be used? How fast must the model rotate? (The diameter of a U.S. standard golf ball is 4.3 cm, dimple depth is 0.02 cm.) The fluid dynamic characteristics of a golf ball are to be tested using a model in a wind tunnel. Dependent parameters are the drag force, Fo, and lift, F, on the hall. The independent parameters include diameter D, airspeed V, angular speed, a, dimple depth, d and air properties. The dimensionless parameters are as follows: pVD eD d F pV2 D F and D pVD pVD oD d H V D " A golf pro can hit a ball at P-60m's and - 6000rpm. To model these conditions in a wind tunnel with maximum speed of 30m/s, what diameter model should be used? What dimple depth should be used? How fast must the model rotate? (The diameter of a U.S. standard golf ball is 4.3 cm, dimple depth is 0.02 cm.)