Must inflow boundary be regular shape?

ytyyutianyun · May 10, 2018, 10:50

When I need to generate mesh for flow simulation, I find people online will use straight line or Semicircular as the inflow plane.
For example,

Can we use irregular shape as inflow plane, such as parabola, zigzag line?

Thank you very much.

LuckyTran · May 10, 2018, 22:46

Yes and it's not so terrible to impose the same inlet BC but you cannot get too arbitrary with the boundary shape (like zig-zag for example).

The issue is you have to calculate the discretized gradient and when you have funny shapes the gradients that you calculate also become funny and affects your results. Having a nice geometry helps you to have a nice mesh to avoid these problems.

May 10, 2018, 10:50	Must inflow boundary be regular shape?	#1
ytyyutianyun New Member anonymous Join Date: May 2018 Posts: 2 Rep Power: 0	When I need to generate mesh for flow simulation, I find people online will use straight line or Semicircular as the inflow plane. For example, Can we use irregular shape as inflow plane, such as parabola, zigzag line? Thank you very much.

May 10, 2018, 22:46		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	Yes and it's not so terrible to impose the same inlet BC but you cannot get too arbitrary with the boundary shape (like zig-zag for example). The issue is you have to calculate the discretized gradient and when you have funny shapes the gradients that you calculate also become funny and affects your results. Having a nice geometry helps you to have a nice mesh to avoid these problems. colinda1 likes this.

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