Effect of Gap on the Aerodynamic Performance of RTA 7025 Double Slotted Airfoil

Recently NAL has taken initiative to design and develop a 70-seater Regional Transport Aircraft (RTA) which is suitable for Indian conditions and can operate with minimum airport infrastructure requirements. An efficient high lift system is one of the key technical requirements to achieve the goals set for RTA. JUMBO2D, a multi-block structured viscous code, has been used to make preliminary analysis of the proposed high lift system for the RTA. The configuration consists of three elements, namely, the main airfoil with nose droop, a vane and a flap. The proposed high lift configuration of RTA has already been analyzed in detail for both take-off and landing conditions with and without nose-droop. The gaps between different elements of double slotted airfoil play a major role in determining the effectiveness of this high lift system. In the present work, effect of the gap, between main element and vane, on the performance of RTA 7025 airfoil has been investigated using JUMBO2D code.