simpleFoam

onurcanpiskin · March 13, 2024, 06:56

Hello, I am performing aerodynamic analysis for external flow. I get results that are far from the drag values I need. I use the K-W SST model. Since I work at 100m/s, my kinetic energy and omega values are very high. I think there is no error in my case file, but my results are very high. Can you help me with this?

Severus · March 13, 2024, 14:05

Hello,
Check out these recent threads
Unable to validate Drag coefficient for Flow past a sphere using OpenFOAM
Drag coefficient of sphere & spherical bubble at Re = 1

For drag the most common reason is the mesh refinement near the wall in order to capture the boundary layer accurately.
It should be well refined. Since you use RANS turbulence modelling, the mesh spacing at the walls should be related to the y+ values.
If you use wall functions, y+ should be between 30 and 100. If you don’t use wall functions (low Re turbulence models), y+ should be less than 5.

A suggestion: Please name your thread better (relevant name) next time so that people in future can find it easily

Thanks

March 13, 2024, 06:56	simpleFoam	#1
onurcanpiskin New Member onurlands Join Date: Feb 2024 Posts: 25 Rep Power: 2	Hello, I am performing aerodynamic analysis for external flow. I get results that are far from the drag values I need. I use the K-W SST model. Since I work at 100m/s, my kinetic energy and omega values are very high. I think there is no error in my case file, but my results are very high. Can you help me with this?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
simpleFoam tutorial PitzDaily using Reynolds stress tensor (LRR RASModel)	dlahaye	OpenFOAM Running, Solving & CFD	24	August 4, 2023 15:29
interFoam vs. simpleFoam channel flow comparison	DanM	OpenFOAM Running, Solving & CFD	12	January 31, 2020 16:26
simpleFoam parallel solver & Fluent polyhedral mesh	Zlatko	OpenFOAM Running, Solving & CFD	3	September 26, 2014 07:53
Laminar simpleFoam and inviscid simpleFoam	herenger	OpenFOAM Running, Solving & CFD	7	July 11, 2013 07:27
Trying to run a benchmark case with simpleFoam	spsb	OpenFOAM	3	February 24, 2012 10:07

March 13, 2024, 14:05		#2
Severus Member Shravan Join Date: Mar 2017 Posts: 75 Rep Power: 9	Hello, Check out these recent threads Unable to validate Drag coefficient for Flow past a sphere using OpenFOAM Drag coefficient of sphere & spherical bubble at Re = 1 For drag the most common reason is the mesh refinement near the wall in order to capture the boundary layer accurately. It should be well refined. Since you use RANS turbulence modelling, the mesh spacing at the walls should be related to the y+ values. If you use wall functions, y+ should be between 30 and 100. If you don’t use wall functions (low Re turbulence models), y+ should be less than 5. A suggestion: Please name your thread better (relevant name) next time so that people in future can find it easily Thanks