# Problems with generated results of 3D wing analysis

 Register Blogs Members List Search Today's Posts Mark Forums Read

March 12, 2010, 10:37
Problems with generated results of 3D wing analysis
#1
New Member

Chong Shao ming
Join Date: Mar 2010
Posts: 1
Rep Power: 0
Hi all,

I am using Fluent to analyse a typical 3D wing problem under low Re. However, the CL which was obtained is way too high in region of 3.7 for AoA of 4!

(selected results from force report)
Force vector: (0.06976 0.997564 0)
pressure total pressure total
force force coefficient coefficient
n n
-------------- --------------
2.2806709 2.2830547 3.7235443 3.7274363
-------------- -------------- -------------- --------------
2.2806709 2.2830547 3.7235443 3.7274363

Could anyone help verify if the parameters used are suitable and correct?

Fluent
(grid checks and scaling have been carried out correctly)
Solver: Pressure-based
Materials: constant density and viscosity
Viscous Model: Spalart-Allmaras (at default values)
Operating Conditions: Op pressure = 101325 Pa
Boundary Conditions: (kindly refer to attached file)
Inlet-velocity inlet
Outlet-pressure outlet

Kindly point out any possible loopholes which i might have in the meshing as well. (FYI airfoil used is GEMINI, c=0.171m, b=1.2)

Attached Images
 Gambit mesh.jpg (100.6 KB, 31 views)

 April 11, 2019, 00:56 #2 New Member   veerappan Join Date: Apr 2019 Posts: 15 Rep Power: 6 that first force vector is x component ? x=sin alpha?

 April 11, 2019, 01:20 3d wing #3 New Member   veerappan Join Date: Apr 2019 Posts: 15 Rep Power: 6 dear seniors actually i am simulating naca4412 3d airfoil wing for downloaded conference paper , in that paper i got results , but my solution is very low in the two order deviated from his values for example . paper result is at 0 AOA , cl=0.0018, cd =-0.05 but my result is cl=0.0016, cd =0.00016 similarly at 5 AOA , PAPER RESULT IS CL=0.2 , CD = 0.1 but my result again cl= 0.0023 , cd = 0.0003 what any thing wrong in inlet parameters what i gave , or in scaling factor , waiting for your response