How do I specify the Heat Exchanger in Simscape to be specifically counter flow and not parallel flow?

Some of the Simscape Heat Exchanger Blocks, such as:
Heat Exchanger (G-G)
https://www.mathworks.com/help/releases/R2020b/physmod/hydro/ref/heatexchangergg.html
Have the option of selecting the "Flow Arrangement" parameter to be "Parallel or Counter flow". That is one single dropdown parameter.
I specifically want my Heat Exchanger to be counter flow. How do I specify the flow to be counter flow if I can only select from the dropdown the parameter that says "Parallel or Counter Flow"? Is there some other parameter I need to specify?

Answer 1

[MathWorks Support Team]

Whether the heat exchanger operates in counter flow or parallel flow depends on how the gas ports of the block are setup.

For the below Heat Exchanger (G-G):

https://www.mathworks.com/help/releases/R2020b/physmod/hydro/ref/heatexchangergg.html#mw_167495c0-101a-4a81-99e0-03e9d23866fc

As mentioned in the documentation, there are 4 gas ports: A1, A2, B1, B2. To set it up to be a counter flow heat exchanger, here is one example of how you can manually setup the gas ports:

Say you have two gases: fluid 1 and fluid 2. 

Set port A1 to be the inport of fluid 1 into the heat exchanger (fluid 1 goes INTO the heat exchanger through A1) and the port B1 to be the outport of fluid 1 (fluid 1 EXITS the heat exchanger through port B1). Then set port B2 to be the inport of fluid 2 (fluid 2 ENTERS) and port A2 to be the outport of fluid 2 (fluid 2 EXISTS). So, physically and visually, you can picture that the heat exchanger now looks like this:

What determines the direction of the fluid flow is the way the model was setup (not related to the internal configuration of the heat exchanger) and the pressure differential properties of your fluid flow. This is done manually. The key here is to make sure whatever fluids you are using are entering and exiting the appropriate Heat Exchanger ports, just like a real heat exchanger setup.