Influence of a Heat Transfer Minimizing Leading Edge on Aerodynamic Performance at Subsonic Speeds for a Generic Delta Wing

In the design of high-speed vehicles, the engineering trade-off between drag, weight, and thermal management is extremely important. At hypersonic speeds, bluntness and shape optimization are effective means of heat flux mitigation. However, increased drag due to these modifications is a known issue. In the case of wide-speed range applications, the impact of such modifications on low-speed performance is of interest. This work presents the results of numerical simulations of a generic delta wing with a finite thickness and swept chamfer with and without a heat transfer minimizing blunt leading edge. Incompressible Reynolds Averaged Navier-Stokes Simulations have been performed using the simpleFoam solver. Simulations were carried out at a chord Reynolds number of 600,000 over angles of attack from 0 to 12 degrees. For all sweep angles, both lift and drag coefficients relative to the unmodified projected area at the highest angle of attack increased for the modified leading edge. However, these effects were most evident for the lowest sweep angle of 50 degrees. Similarly, a decrease of the max lift-to-drag ratio of approximately 7\% was observed for this sweep angle. The changes in flow patterns and aerodynamic performance at subsonic speeds are subsequently highlighted and discussed. The results show that the observed changes in performance are due to the influence of the leading edge shape on the leading edge suction at the nose of the proposed geometry. Finally, comparisons between present results and those provided by the Polhamus theory are reported. Results comparison suggest a rather good agreement between present data and Polhamus theory.