Excessive temp. within boundry layer for roughness 0.0003 to 0.0007m

Roh · July 23, 2018, 09:16

Good afternoon
Trying to simulate roughness (0.0003m to 0.0007m roughness height) in a nozzle and investigate the effect of roughness on mass flow rate but there is a problem. I get excessive temp. here is a screenshot of the contour of static temperature:

As you can see at the throat this excessive temp. has taken place. why? Any idea to figure it out?

LuckyTran · July 25, 2018, 14:46

Have you tried remeshing?

Roh · July 26, 2018, 02:24

Thank you for your response
Well no, To have mesh for roughness 0.0007m and fully rough(epsilon plus >70 or k+>80) I think I need to have a mesh with 0.0014m (two times of 0.0007) hight for first cell near the wall. I think my mesh is not that bad. If you think I need to re-mesh this flowfield, please let me know what's your idea to re-mesh it.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[snappyHexMesh] Help with Snappy: no layers growing	GianF	OpenFOAM Meshing & Mesh Conversion	2	September 23, 2020 08:26
[snappyHexMesh] snappyHexMesh Boundary Layer at Corner	panpanzhong	OpenFOAM Meshing & Mesh Conversion	5	July 3, 2018 05:53
Prismatic boundary layer	KateEisenhower	enGrid	5	September 15, 2015 07:48
CAD to SALOME with Structured Boundry Mesh layer	Annuminas	Mesh Generation & Pre-Processing	0	November 18, 2013 07:29
errors	Fahad	Main CFD Forum	0	March 23, 2004 13:20

July 25, 2018, 14:46		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	Have you tried remeshing?

July 26, 2018, 02:24		#3
Roh Senior Member Join Date: Sep 2017 Posts: 130 Rep Power: 8	Thank you for your response Well no, To have mesh for roughness 0.0007m and fully rough(epsilon plus >70 or k+>80) I think I need to have a mesh with 0.0014m (two times of 0.0007) hight for first cell near the wall. I think my mesh is not that bad. If you think I need to re-mesh this flowfield, please let me know what's your idea to re-mesh it.