Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing

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2018
Sharifi Ghazijahani, Mohammad
Flow characterization over delta wings have gained attention in recent decades due to their prevailing usage in designs of unmanned air vehicles (UAVs). In literature,only a few studies have reported wing thickness effect on both the aerodynamic performance and detailed flow structure over delta wings. In the present investigation, the effect of thickness-to-chord (t/C) ratio on aerodynamics of a non-slender delta wing with 45 degree sweep angle is characterized in a low-speed wind tunnel using laser illuminated smoke visualization, surface pressure measurements, particle image velocimetry, and force measurements. The delta wings with t/C ratios varying from 2 % to 15 % are tested at broad range s of angle of attack and Reynolds number. The results indicate that the effect of t/C ratio on flow structure is quite substantial. Considering the low angles of attack where the wings experience leading edge vortex structure, the strength of the vortex structure increases as the t/C ratio increases. However, low t/C ratio wings have pronounced surface separations at higher angle of attack compared to the high t/C ratio wings. These results are well supported by the force measurements such that high t/C ratio wings induce higher lift coefficients, CL, at low angles of attack, whereas maximum CL values are higher and appear at higher angle of attack for low t/C ratio wings. This indicates that low t/C ratio wings are more resistive to the stall condition. Considering the lift-to-drag ratio, CL/CD, increase in t/C ratio induces remarkable drop in CL/CD values.

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Citation Formats
M. Sharifi Ghazijahani, “Effect of thickness-to-chord ratio on aerodynamics of non-slender delta wing,” M.S. - Master of Science, Middle East Technical University, 2018.