Shock Reduction through Opposing Jets—Aerodynamic Performance and Flight Stability Perspectives.

Rashid, Shagufta; Nawaz, Fahad; Maqsood, Adnan; Riaz, Rizwan; Salamat, Shuaib

In this research paper, investigations of counter flow (opposing) jet on the aerodynamic performance, and flight stability characteristics of an airfoil with blunt leading-edge in supersonic regime are performed. Unsteady Reynolds-Averaged Navier-Stokes ( U R A N S ) based solver is used to model the flow field. The effect of angle of attack (α), free-stream Mach number ( M ∞ ), and pressure ratio ( P R ) on aerodynamic performance of airfoil with and without jet are compared. The results indicate that the opposing jet reduces drag from 30 % to 70 % , improves the maximum lift-to-drag ratio from 2.5 to 4.0, and increases shock stand-off distance from 15 % to 35 % depending on flow conditions. The effect of opposing jet on longitudinal flight stability characteristics, studied for the first time, indicate improvement in dynamic stability coefficients ( C m q + C m α ˙ ) at low angles of attack. It is concluded that the opposing jet can help mitigate flight disturbances in supersonic regime.

MACH number; FLIGHT; DYNAMIC stability; AERODYNAMICS research; FLOW meters; TRANSONIC flow; AEROFOILS

Applied Sciences (2076-3417), 2020, Vol 10, Issue 1, p180

2076-3417

Academic Journal

10.3390/app10010180