Dye Visualization of the Vortical Flow Structure over a Double-Delta Wing

An investigation of the flow field around a double-delta wing was carried out at the Aerodynamics Analysis and Design Laboratory's (AADL) water tunnel facility. The model has a sharp leading edge and 76/40 degrees configuration, which is representative of current fighter aircraft. The experiments were conducted at Reynolds numbers of 10,000 and 15,000. The dye injection technique was utilized to analyze the flow. A comparison of the vortical flow structure and the bursting point locations was done for a Reynolds number of 15,000 and found to be in reasonable agreement. The major objective of this experiment was to study the effect of the angle of attack (AOA) and Reynolds number on the vortical flow structure. In this flow visualization result, the dominant feature of the AOA and Reynolds number effect on the vortical flow structure over the double-delta wing has been observed. With increasing Reynolds number, the distance between the vortex trajectory and the model surface becomes smaller. As the AOA increases, the intertwining or coiling up features cannot be seen and the vortex bursting point locations move upstream. The distance between the vortical streakline and the model surface becomes larger with increasing AOA. The crossover point of the main and strake wing vortices also depends on the AOA. DOI: 10.1061/(ASCE)AS.1943-5525.0000195. (C) 2012 American Society of Civil Engineers.