Flow Analysis Custom Blocks

Let’s take a look at three custom blocks you can implement in your flow analysis. We’ll start with the Mass Flow Rate custom block. This block will translate a mass flow rate into a velocity boundary condition. It has five inputs: the boundary, mass flow rate, direction, area, and density. We can start by defining our boundary, which is just our inlet boundary. In this case, we’ll define a mass flow rate in g/s, or we can use more conventional units.

Define your direction as a vector and input your area. Here we’ve just sectioned our fluid body using a plane from normal, calculated our surface area, then divided by two to account only for the inlet rather than the inlet and the outlet. Finally, we’ll apply a fluid density and use our mass flow rate as our velocity boundary condition in our flow analysis. Note that the output type for our Mass Flow Rate block is velocity. After running a flow analysis, you can evaluate your results using the Flow Analysis Results on Boundary block, or you can use either of the Pressure Drop custom blocks that we’ve provided. The first will evaluate pressure drop across virtual boundaries. You can add in your flow analysis, your inlet boundary, and your outlet boundary, granted they’re virtual boundaries that were set up on implicit bodies. Once the block runs, your pressure drop will appear in the top right corner. If instead of virtual boundaries, you set up CAD boundaries, you also have the option to use our second custom block that evaluates the pressure drop across CAD boundaries. Here you would follow a similar setup, pulling in your flow analysis results and your CAD boundaries one and two.