When meassure Cd or Cl of airplane/car in wind tunnel, does number change at different speeds, for example at 100km/h compare to 250km/h? If yes,how much?
I know from theory that coefficents change with Re, and Re is change with speed, but I know what real pracital data show when you change airflow speed in wind tunnel?
Because if difference in results is big then we have to agree at what speed test the object..