numerical investigation of delta wings leading edge configuration effects on the flow behavior using large eddy simulation approach

determining characteristics and behavior of fluid flow and obtaining the aerodynamic coefficients are important and considerable tasks in investigation of flow over the bodies. in this research, leading edge radius effects on the flow behavior over a delta wing with a sweep angle of 50 degree at different reynolds numbers between 0.5×106 and 2.5×106 are investigated numerically. three different leading edge models including one sharp and two round (having different radius) are studied. validation of the results is performed using available experimental results which showed good agreements. leading edge radius effects on the aerodynamic coefficients and size and location of the vortices are investigated. based on the obtained results, on a fixed angle of attack, increasing the wing leading edge radius reduces the moment coefficient. also, it decreases size and strength of the preliminary vortex and magnitude of the lift and drag forces. when the reynolds number varies between 0.5×106 and 0.97×106, the lift coefficient tends to experience a 6 to 8 percent raise, while at higher reynolds numbers, no considerable raisings observes. also, at angle of attacks of 20 and 25 degrees, by increasing the reynolds number, the lift coefficient graph experiences a noticeable reduction. at the sharp leading edge delta wing, stronger vortices generate which results higher lift coefficient. by rounding the leading edge, due to weakening the aforementioned vortices, the lift coefficient decreases.