The evaluation of lift and drag force for solid body with micro dimple

Abstract

The present study explores the lift and drag mechanism, pressure distribution along the chord and flow visualization of the debossed dimpled- aerofoil with the aim to evaluation the effect of dimples on the aerodynamic characteristic on the aerofoil and find an optimisation on the dimples parameter in improving the aerodynamic performance. The issues on the fuel consumption, energy cost, aerodynamic performance efficiency for aerofoil application in turbine, automotive especially under unexpected weather condition such as air turbulence in air flight lead to the concern on improving the aerodynamic performance from time to time. In current context, the interaction of the dimple parameters influencing the aerodynamic behaviour of the aerofoil such as the dimple aspect ratio, shape, pitch resulting in variation of number of dimple is considered. An aerofoil sized 0.14m x 0.148m is tested under wind tunnel with different angle of attack and air velocity. The aerofoil flow visualizations under smoke test are captured with a high speed camera. A comparative study of the smooth and dimpled aerofoil with cylindrical (bluff) and hexagonal (blunt) dimple shape is investigated. From the result it is shown with the integration of dimple, the lift performance of the aerofoil is greatly improved with the delay of flow separation as a result from the streamwise vorticity reduces the turbulent skin drag. thus increasing the lift and the controllability of the aerofoil. The cylindrical dimpled aerofoil with the aspect ratio of 0.4 and pitch 8500 μm is highly recommended with the highest lift and lowest drag.