I want to calculate the normal forces on a surface. Currently, I am using ParaView for the post processing. In the ParaView, I am using the clip function to the surface I want to find out the normal forces. Then I am using the pressure functor and exporting the pressure values on that surface through csv file. Then I am taking a mean of the pressure values and multiplying by the area of the surface to get the normal forces.
Is there any other better method to implement? By this method, I am getting error in the value of the normal force. Like the Wall shear stress functor, is there any other functor from which I can get the normal forces?