CFD Analysis of High-Lift Devices on the SC-1094R8 Airfoil

This paper compares the effect of three trailing-edge high-lift devices on the SC-1094R8 airfoil. The devices considered were a trailing-edge Gurney Flap (GF) at 0.5, 1, 1.5, and 2% chord, a 20% chord Trailing-Edge Flap (TEF) deflected to 2°, 4°, and 6°, and an extendable Trailing-Edge Plate (TEP) extended to 10% or 20% of the baseline chord at deployment angles of 2° and 4° to the chord line. The quasi-steady, 2D lift, drag, and pitching moment coefficients were calculated using the TURNS Navier- Stokes CFD code. For the device deflection amplitudes considered, increase in maximum lift coefficient with a TEF was significantly lower than that achieved with the TEP and the GF. However, the GF has a much larger drag penalty at lower lift coefficient values. For the maximum increases in lift coefficient with the different devices over the deflection range considered, the nose-down pitching moment penalty is the highest for the GF at lower angles of attack but the TEP moment penalty becomes comparable at higher angles of attack approaching stall. The TEF moment penalty is the lowest of the three. Since TEFs and GFs can be deployed at high frequency and are of potential interest for vibration/noise reduction and performance improvement, the study also focused on comparing their efficiency in terms of increment in lift or moment per unit increment in drag at low to moderate angles of attack (prior to stall). Due to the large drag penalty suffered by GFs, the TEF appears to be more efficient from an aerodynamic standpoint for vibration/noise/performance improvement applications.