Numerical Study of Transonic Flow Characteristics Around a Compound Delta Wing

This study numerically examines the aerodynamic characteristics of a compound delta wing, designed with multiple sweep angles to enhance transonic performance. Inspired by the wing design of the HAL Tejas, the leading-edge sweeps are strategically positioned to reduce wave drag while maintaining lift across a broad flight envelope. Computational fluid dynamics (CFD) simulations were conducted at Mach numbers of 0.75, 1.0, and 1.1, with angles of attack ranging from 0° to 55°. The Unsteady Reynolds-averaged Navier–Stokes (URANS) approach, coupled with the Spalart–Allmaras (SA) turbulence model, was employed for its efficiency in capturing external aerodynamic flows with reasonable computational cost. The numerical model was validated against experimental data by comparing surface pressure distributions and lift coefficients of delta wings. The compound delta wing’s performance was benchmarked against a baseline single-sweep delta wing. Results indicate a significant drag reduction at Mach 1, with decreases of 17.38%, 12.50%, and 13.25% at angles of attack of 5°, 30°, and 55°, respectively. Although the maximum lift coefficient exhibited a slight reduction of 5.17%, the lift-to-drag ratio improved by 11.10%, 14.89%, and 7.24% at the same angles of attack. These findings demonstrate that the compound delta wing configuration enhances aerodynamic efficiency in the transonic regime, confirming its potential for improved aircraft performance.