Low Lift Coefficient in ground simulations of 2D Airfoil (URGENT)

Umayr91 · April 7, 2021, 05:56

Hi there, I am university student and in major need of help. I'm running 2d simulations on a 30P30N Airfoil which I've simulated in free flight and now I have run in ground simulations with a h/c of 1. My lift values for ground are lower than my free flight simulations for whatever reason and I cannot figure it out despite many changes. Can anyone assist? These are my results:

FREE FLIGHT
Alfa CL - CD - CM
0 - 2.1414 0.050072 0.22063
4 - 2.6703 0.050454 0.09339
8 - 3.1056 0.064482 -0.03591
12 - 3.3856 0.093385 -0.16095

IN GROUND
Alfa CL - CD - CM
0 - 2.0035 0.044599 0.20268
4 - 2.3253 0.036799 0.07713
8 - 2.6291 0.052558 -0.04001
12 - 2.8262 0.079061 -0.14552

I've attached some pictures of basic settings/reference values:
Screenshot 2021-04-07 at 10.52.49.jpg

Screenshot 2021-04-07 at 10.53.22.jpg

Screenshot 2021-04-07 at 10.53.50.jpg

I would really appreciate some urgent help as my degree depends on it. Thank you so much for your time.

Umayr91 · April 7, 2021, 06:02

A couple more settings

Screenshot 2021-04-07 at 11.00.40.jpg

Screenshot 2021-04-07 at 11.01.14.png

MekTek · April 25, 2021, 04:51

How does your mesh settings look like?

April 7, 2021, 05:56	Low Lift Coefficient in ground simulations of 2D Airfoil (URGENT)	#1
Umayr91 New Member Umayr Join Date: Apr 2021 Posts: 2 Rep Power: 0	Hi there, I am university student and in major need of help. I'm running 2d simulations on a 30P30N Airfoil which I've simulated in free flight and now I have run in ground simulations with a h/c of 1. My lift values for ground are lower than my free flight simulations for whatever reason and I cannot figure it out despite many changes. Can anyone assist? These are my results: FREE FLIGHT Alfa CL - CD - CM 0 - 2.1414 0.050072 0.22063 4 - 2.6703 0.050454 0.09339 8 - 3.1056 0.064482 -0.03591 12 - 3.3856 0.093385 -0.16095 IN GROUND Alfa CL - CD - CM 0 - 2.0035 0.044599 0.20268 4 - 2.3253 0.036799 0.07713 8 - 2.6291 0.052558 -0.04001 12 - 2.8262 0.079061 -0.14552 I've attached some pictures of basic settings/reference values: Screenshot 2021-04-07 at 10.52.49.jpg Screenshot 2021-04-07 at 10.53.22.jpg Screenshot 2021-04-07 at 10.53.50.jpg I would really appreciate some urgent help as my degree depends on it. Thank you so much for your time.

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April 7, 2021, 06:02		#2
Umayr91 New Member Umayr Join Date: Apr 2021 Posts: 2 Rep Power: 0	A couple more settings Screenshot 2021-04-07 at 11.00.40.jpg Screenshot 2021-04-07 at 11.01.14.png

April 25, 2021, 04:51		#3
MekTek New Member Venkat Join Date: Apr 2019 Location: Bengaluru Posts: 7 Rep Power: 7	How does your mesh settings look like?