An Experimental Study on the Coherent Structures in the Initial Region of an Annular Jet.

An experimental investigation of coherent structures in the axisymmetric mixing layer of an annular jet was carried out. The Reynolds number, based on the outer diameter of the annulus, was 2.17 X 105 The flow structures of the shear layer at several downstream stations, all within 3 outer diameter distance, were examined. Conditional sampling technique was employed to educe naturally occuring large-scale structures. Coherent vorticity and coherent Reynolds stresses were, measured. It was found that the evolution of large-scale vortical structure is completed within the distance of 2 outer diameters and that the coherent Reynlods stress increases rapidly during the evolution of large-scale structure

Transonic Flow Analysis for Wing-Body-Tail Combination Using Small Disturbance Equation

Transonic flow field analysis of wing-body-tail combination was attempted by modifying the existing code, known as WIBCO, written for the analysis of wing-body combination, which was based on small disturbance equation.The results obtained from the new code were both phsical and reasonable when compared to the results obtained from the original code. The directions and ideas to modify the code with more flexibility to calculate various combinations have been pointed out