incorrect drag and lift coefficient (smooth ball vs golf ball)

- May 9, 2024 at 1:59 pm
  
  Jim Beet
  Subscriber
  
  I am conducting a simulation to compare the drag and lift coefficients of a smooth sphere and a golf ball under various rotational speeds and flow velocities. However, I have encountered difficulties with the smooth sphere simulation. The computed drag coefficient and lift coefficient differ significantly from those reported in previous studies. While past research indicates a decrease in the drag coefficient and an increase in the lift coefficient, my simulation results show the opposite trend. Specifically, I obtained a negative lift coefficient and a very small drag coefficient of 0.0216, which is substantially lower than the values reported in the literature (ranging between 0.4 to 0.5). I have checked my simulation setup, and the results appear to have converged. Could someone help me on what I am doing wrong.
- May 17, 2024 at 1:42 pm
  
  Federico
  Ansys Employee
  
  Lift and drag coefficient will be highly dependent on surface mesh and boundary layer solution.
  How does your mesh look near the ball?