Please, find below references for useful information:

1) Spalart, P. R., and Rumsey, C. L., “Effective inflow conditions for turbulence models in aerodynamic calculations,” AIAA journal, vol. 45, 2007, pp. 2544–2553

2) The Importance of Turbulence in Assessment of Wind Tunnel Flow Quality . http://cdn.intechweb.org/pdfs/16897.pdf

Article Adaptive control of turbulence intensity is accelerated by f...

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Calculate the amount of drag in ideal mode and make an error analysis using the final value

Better to use wind tunnel balance to measure aerodynamic forces to get rid of wind tunnel turbulence effect on lift or drag forces.

The permissible wind tunnel turbulence intensity is well known that between(0.3-0.4). The purpose is based on measuring the turbulence intensity levels when different turbulence grids are fixed upstream of the test section, and compare them to the case when no turbulence grid is present.

The turbulence intensity levels in the entry of the wind tunnel test section used for investigation of the aeroelastic instability of an airfoil when the inlet part of the wind tunnel is free, the turbulence level at the airfoil leading edge ranges from 0.28% to 0.37%. When the fine turbulence grid G1 is mounted, the turbulence intensity is 1.79% for the lowest flow speed Ma = 0.1 and 1.01% for the highest possible flow speed Ma = 0.3. The coarse turbulence grid G2 induces turbulence levels ranging from 2.65% to 1.62%, decreasing with increasing flow velocity.

Thank you all for your help. I find solution to my problem in the following paper:

Wang, S., Zhou, Y., Alam, M. M., & Yang, H. (2014). Turbulent intensity and Reynolds number effects on an airfoil at low Reynolds numbers. Physics of Fluids, 26(11), 115107