How to change flow direction in simscape

How can I create a port in a constant volume block in MATLAB Simscape (using the MA domain) that is oriented 90 degrees to the flow direction? Please provide recommendations.

[Yifeng Tang]

Hi @정수 이

Could you please provide more information on your comment that " I would like to simulate the phenomenon where the flow is delayed due to a 90-degree change in direction."? Maybe a simple diagram?

Are you thinking about a volume attached to the side of a pipeline, which may experience a delay in reaching state balance, for example temperature, because the flow isn't going directly through the volume?

[정수 이]

Thank you for your comment, Yifeng Tang. As shown in the attached diagram, it is indeed the volume attached to the side of the pipeline as you mentioned. Due to the change in the flow direction, the flow collides with the wall during the bending process, causing stagnation and a delay phenomenon.

[Yifeng Tang]

Hi @정수 이

The flow collision with the wall is not a "one-dimentional" feature of the flow any more. The separation bubble and recirculation you showed are 2-D and 3-D features of the flow, which isn't going to be fully represented in 1D modeling tools like Simscape.

We'll have to think about the "effect" of such features on the 1D flow. To me it feels like a reduction in flow rate which would otherwise (e.g. in a straight pipe) be larger. This can be modeled with a flow resistance or use the "Aggregate equivalent length of local resistances" parameter in Pipe to model the addition flow resistance. You can also use an Elbow (MA) block and see if it provides reasonable pressure drop.

I believe the delay phenomenon also requires you model the fluid volume accurately. Parametrize the pipe blocks to account for all the volumes. If capturing the gradient within the pipe is important, you'll need to use multiple, shorter pipes.

Hope this helps.

Answer 1

[Divyanshu]

Hello @정수 이,

There is no such option or parameter in the 'Constant Volume Chamber (MA)' block which can enable you to specify/create a new port which is oriented 90 degrees to the flow of direction.

A possible way to achieve this can be to to create custom component or generate custom blocks from simscape component files. To get started you can refer the following links:

• Custom Components
• Custom blocks from Simscape Component Files
• Creating custom component from existing blocks

Hope it helps!

[정수 이]

Thank you for your response. Creating a custom model seems a bit challenging for me. Is there a way to achieve this using the existing blocks? I would like to simulate the phenomenon where the flow is delayed due to a 90-degree change in direction. It would be great if you could share any related examples or methods. Thank you!