Doubt about External Flow Simulation

Hi, I'm going to try to be as clear as possible because my English is not good enough

I've designed a paddle that needs to be partially submerged in a canal. The paddle moves through the canal, i know that i can't simulate the movement of the paddle instead, i´ve simulated a flow through the paddle. I've obtained the force acting on the paddle.

The problem is that i need to obtain the force acting on the paddle when i suddenly change the direction of the movement of the paddle when it is already moving in the first direction. I know that this force needs to be higher than the first but i don't know how to set the parameters for the new simulation.

I've inserted an image of the paddle (the computational domain simulates the volume of the canal).