Abstract

Effects of Reynolds number on tip vortex characteristics of two different wing geometries at three Reynolds numbers 1.82 x 105, 3.12 x 105 and 4.16 x 105 have been studied in this investigation for various angles of attack. A sweptback tapered wing and a slotted raked wingtip were the two configurations considered for this study. The parameter which changed the most was the free stream velocity to obtain different Reynolds numbers keeping other parameters constant. The numerical results obtained for tangential velocity, lift coefficient and drag coefficient of sweptback tapered NACA 0015 wing were compared with the experimental results to validate the CFD code. The numerical results that were obtained by using CFD code show a good agreement with the experimental results. The effect of Reynolds number on non-dimensional aerodynamic parameters was noticed at higher angles of attack. The effect was visible only at angles of attack greater than 8° for lift coefficient and for drag coefficient after 6oangle of attack. Maximum CL and stalling angle were increased with Reynolds number for both the configurations but the drag coefficient was found to be decreased with increase in Reynolds number. But the dimensional aerodynamic parameters were found to increase with the Reynolds number. It was also observed that the aerodynamic efficiency of slotted raked wingtip was higher compared to the sweptback tapered wing configuration for all the three Reynolds numbers.

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