Aerodynamic and Performance Evaluation of a Variable-Sweep Morphing Wing

This paper reports on a numerical and experimental investigation of a variable-sweep morphing wing for an unmanned aerial vehicle (UAV) whereby the area and the aspect ratio of the wing can change while its overall configuration is kept nearly unchanged. The numerical results were obtained using computational fluid dynamics (CDF) and the experimental data from a low-speed wind tunnel test at the speeds of 50, 60, and 70 m/s. The extent of change in the sweep angle of the morphing wing relative to the base wing is 12 degrees (i.e. 36%). The results of this study show that lift coefficient, lift curve slope, drag coefficient and the aerodynamic efficiency of the model wing decrease as the sweep angle increases. According to experimental results, the maximum reduction in the drag coefficient of the morphing wing is 6.1% as the sweep angle increases from 33 to 45 deg. Also, the maximum changes in the aerodynamic efficiency of the model with sweep angle changing from 33 to 45 degrees occur at 6 degree angle of attack, which is equal to 11.6%. With changing the wing sweep, the maximum change of flight range and endurance were found to be 8.77 and 7.15%, respectively.