Investigation of air flow over delta and cranked arrow delta wings

Abstract EN

Delta wing shapes are unique in their structure advantages and aerodynamic characteristics.

On supersonic designing, a delta wing shape is often used to reduce drag and achieve the optimal performance.

In this study, a commercial software (ANSYS 15) is used to investigate the performance of two delta wing shapes (simple delta wing and cranked arrow delta wing) at different angles of attack (5° to 65°) and different flow speeds (M = 0.15 to 1.4) in order to obtain the lift and drag coefficients, pressure distribution around the investigated wings, and velocity filed.

The results indicate that: (i) at subsonic speed (M = 0.15 to 0.8), the lift coefficient for the cranked arrow delta wing increases by about 25%.

While the drag coefficient in case of cranked arrow delta wing increases by a value reaches 5%, as the area of the cranked arrow delta wing is less by about 7%, this leads to decreasing drag force for the cranked arrow wing, which improves its performance.

The lift and drag coefficients increase with increasing Mach number, the rate of increase is higher in the cranked arrow delta wing.

In cranked arrow delta wing, vortex breakdown is delayed than that in simple delta wing, which makes the cranked arrow more stable.

In addition, the cut parts from cranked arrow at trailing edge help to avoid the effect of vortex breakdown on the wing.

(ii) At supersonic speed (M = 1.2 to M = 1.4), the lift coefficient of the cranked arrow delta wing is higher than that for simple delta wing by about 15%, while the increase in the drag coefficient does not exceed 2%, which increases cranked arrow wing’s performance.

The lift and drag coefficients decrease with increasing Mach number, the rate of decrease is higher in the cranked arrow delta wing.

In the cranked arrow delta wing as Mach number increases, a better pressure distribution over the wing surface is observed which improves the stability during flight and maneuvering.