Question About Air Density in drag_coefficient.py #11
Description
First of all, congratulatoins on Transolver++. Thank you for this wonderful project! I really appreciate the effort and work put into it.
I was going through the code in utils/drag_coefficient.py and noticed that the air density is set to 0.3. From my understanding, a typical air density at sea level is around 1.225 kg/m³, and even at higher altitudes, it generally remains above 0.7 kg/m³ under most conditions.
Is there a specific reason for choosing 0.3 here? I just wanted to clarify in case I’m missing some context.
Thanks again for this fantastic project—looking forward to seeing it evolve!
drag_force = calculate_drag_force(cell_areas, normal_surf[:, -1], press_surf, grad_u[:, -1], np.array(1.8e-5))
nu = 72 / 3.6
air_density = 0.3
cd = (2 / ((nu ** 2) * A * air_density)) * drag_force
return cd