[ICEM] Heart modeling - ICEM Hexa Mesh quality improvement

heart_modeller · April 3, 2016, 04:46

Hello everyone!

I'm very new to CFD and ANSYS, so very much appreciate your help in advance to my questions!

My project involves the simulation of blood flow in the left ventricle (LV) of the human heart, so far I have created a series of geometries of the LV at different time points. What I'm doing now is wanting to generate a volume mesh in ICEM, which I will then import into FLUENT for dynamic mesh simulation.

Before I do the simulation in FLUENT, I want to make sure the quality of the mesh I've generated is good. At this stage, I've followed the ICEM tutorial and generated a Hexa mesh for one of my geometries (at time point 1).

My problem is, the mesh I generated seems to be of low quality (as demonstrated by Angle and Determinant 3x3x3). I tried to use o-grid at areas where the quality is low (e.g. at the Apex), but it seems to make it even worse.

My question is, how should I proceed to improve the quality of my mesh, and what other parameters do I need to be aware of to assess the quality of my mesh?

The relevant files for the mesh is here, note this is without o-grid:

https://www.dropbox.com/sh/tgj0tqq8j...JFvOSr_Qa?dl=0

thanks!!
Jason

shereez234 · April 8, 2016, 08:16

Blocking strategy is wrong.. Initial Blocking at Inlet and Outlet in Z direction is correct but you need to assosciate the edges to curves properly. This is not your main problem though. At inlet you have 3 blocks in Z direction which then you have merged into 2 blocks in Z direction when it goes to Internal Fluid. This seemed to have made the blocks to a wedge shape near inlet. Try to continue with three blocks until the end of the geometry. Also split the edges using Spline or Linear and move nodes around to get the right shape of the Ventricle surface. And Put the O grid then and you are good to go I guess.

April 3, 2016, 04:46	Heart modeling - ICEM Hexa Mesh quality improvement	#1
heart_modeller New Member Join Date: Apr 2016 Location: Australia Posts: 3 Rep Power: 10	Hello everyone! I'm very new to CFD and ANSYS, so very much appreciate your help in advance to my questions! My project involves the simulation of blood flow in the left ventricle (LV) of the human heart, so far I have created a series of geometries of the LV at different time points. What I'm doing now is wanting to generate a volume mesh in ICEM, which I will then import into FLUENT for dynamic mesh simulation. Before I do the simulation in FLUENT, I want to make sure the quality of the mesh I've generated is good. At this stage, I've followed the ICEM tutorial and generated a Hexa mesh for one of my geometries (at time point 1). My problem is, the mesh I generated seems to be of low quality (as demonstrated by Angle and Determinant 3x3x3). I tried to use o-grid at areas where the quality is low (e.g. at the Apex), but it seems to make it even worse. My question is, how should I proceed to improve the quality of my mesh, and what other parameters do I need to be aware of to assess the quality of my mesh? The relevant files for the mesh is here, note this is without o-grid: https://www.dropbox.com/sh/tgj0tqq8j...JFvOSr_Qa?dl=0 thanks!! Jason

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April 8, 2016, 08:16		#2
shereez234 Senior Member M Sereez Join Date: Jan 2014 Location: England Posts: 352 Blog Entries: 1 Rep Power: 13	Blocking strategy is wrong.. Initial Blocking at Inlet and Outlet in Z direction is correct but you need to assosciate the edges to curves properly. This is not your main problem though. At inlet you have 3 blocks in Z direction which then you have merged into 2 blocks in Z direction when it goes to Internal Fluid. This seemed to have made the blocks to a wedge shape near inlet. Try to continue with three blocks until the end of the geometry. Also split the edges using Spline or Linear and move nodes around to get the right shape of the Ventricle surface. And Put the O grid then and you are good to go I guess.