2 Replies Latest reply on Oct 9, 2011 3:57 AM by Oliver Kiss

# Determine drag and upthrust

Hi everyone!

I have a question for you. When I make a flow simulation to determine drag or upthrust is the result reduced at the center of gravity of the part?

• ###### Re: Determine drag and upthrust

No, it's not at the center of gravity, but you can determine the center of force application by this method:

How to locate the point of application of a force:

The point of application of a force can be determined by using the definition of torque (M): M=[r*F]. Where r is a vector for the force application point from the coordinate system center, F – force vector, M – torque vector. In SW Flow Simulation you can get the components of force and torque. So, you can solve the equation regarding r. The equation can be rewritten regarding coordinates as the following:

Mx=y*Fz-z*Fy

My=z*Fx-x*Fz

Mz=x*Fy-y*Fx

Here (Mx, My, Mz) – torque components, (Fx, Fy, Fz) – force components, (x, y, z,) – coordinates of force application point. We have three equations and three unknown values therefore (x, y, z) can be found from these equations.

• ###### Re: Determine drag and upthrust

Thanks! You right! Good mental process.