[Shirock]

Hi,

I am modelling a water droplet motion through a gas channel and I want to calculate the drag force on that droplet. Therefore I need the pressure drag and the viscous drag on the isosurface which indicates the droplet.

The gas flow and hence the droplet movement is in inverse x-direction.

For the pressure drag I calcute areaInt(Total Pressure * Normal X)@Isosurface 1

For the viscous drag I define a new variable as gradient velocity u and calculate areaInt(Variable * 5e-06 [Pa s])@Isosurface 1

My Question is if the two equations are the right ones and if not what do I have to use instead. The problem is, that for different gas velocities the pressure drag is sometime positive sometime negative. The viscous drag is always positiv.

Every help would be highly appreciated.

Best regards.