Control of Transonic Shock Wave Oscillation over a Supercritical Airfoil

Muhammad Rizwanur Rahman,Toshiaki Setoguchi,Mohammad Itmam Labib,Mohammad Saddam Hossain Joy,Heuy Dong Kim,Abul Bashar Mohammad Toufique Hasan

doi:10.4236/ojfd.2015.54031

Muhammad Rizwanur Rahman, Toshiaki Setoguchi + Show 4 more

Open Access

https://doi.org/10.4236/ojfd.2015.54031

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Abstract

In the present study, a numerical investigation is carried out on the aerodynamic performance of a supercritical airfoil RAE 2822. Transonic flow fields are considered where self-excited shock wave oscillation prevails. To control the shock oscillation, a passive technique in the form of an open rectangular cavity is introduced on the upper surface of the airfoil where the shock wave oscillates. Reynolds Averaged Navier-Stokes (RANS) equations have been used to predict the aerodynamic behavior of the baseline airfoil and airfoil with cavity at Mach number of 0.729 and at angle of attack of 5°. The aerodynamic characteristics of the baseline airfoil are well validated with the available experimental data. It is observed that the introduction of a cavity around the airfoil upper surface can completely stop the self-excited shock wave oscillation and successively improve the aerodynamic characteristics.

Highlights

Transonic flow field is characterized by several simultaneous physical phenomena such as shock waves, shock wave/boundary layer interaction (SWBLI), flow instability, boundary layer separation and boundary layer thickening
Before going to the detail discussion on present study, the computational results of transonic flow over RAE 2822 supercritical airfoil have been validated with the available experimental test data from AGARD case A6 [21]
Self-excited and self-sustained shock wave oscillation is observed for the baseline RAE 2822 airfoil at the flow conditions under present investigation

Summary

Introduction

Transonic flow field is characterized by several simultaneous physical phenomena such as shock waves, shock wave/boundary layer interaction (SWBLI), flow instability, boundary layer separation and boundary layer thickening. These phenomena limit the cruise speed creating drag rise and buffet onset. This large scale shock induced oscillation has many undesirable unsteady effects including fluctuations in lift and drag coefficients, aero acoustic noise and vibration, buffeting, aileron buzz, periodic flows in supersonic intakes, cascades and so on. Zhao et al [5] performed an experimental study on shock oscillations over SC (2)-0714 supercritical airfoil and found that the phenomenon was two dimensional in the symmetric plane

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