This work uses numerical methods and established programs for solving differential equations of the axisymmetric flow and the plane flow to study the influence of transonic effects for the two cases. | Vietnam Journal of Mechanics, VAST, Vol. 32, No. 1 (2010), pp. 27 – 36 STUDY OF TRANSONIC EFFECT OF FLOWS AROUND SLENDER BODIES OF REVOLUTION AND PLANE PROFILES Hoang Thi Bich Ngoc Hanoi University of Technology Abstract. Transonic effect with presence of local supersonic terminated by shock wave is not wished. In spite of wishes or not, the appearance of shock waves is not avoided. Strong shock waves cause losses, even a grand decrease of aerodynamic quality in fluid-solid interaction. However, under certain conditions, transonic effect increases the drag and at the same time increases the lift leading the amelioration of aerodynamic quality. This work uses numerical methods and established programs for solving differential equations of the axisymmetric flow and the plane flow to study the influence of transonic effects for the two cases. 1. INTRODUCTION Shock wave is a special phenomenon for supersonic flows. Transonic flows include supersonic regions, so the shock wave is a phenomenon usually attached to transonic flows. Properties of shock wave depend on the geometry and free Mach number. For the same main section, transonic effects are very much different between plane flow and flow of revolution. With the hypothesis of potential flow, the calculation of flows around slender bodies of revolution is carried out by solving small disturbance potential equations. Numerical results of the established program are compared with published experimental and numerical results. For flows around plane profiles, transonic effect attached shock wave much stronger than transonic effect in axisymmetric flows under the same conditions. Therefore, the small disturbance method is not adequate for plane flows. In this case, solving full potential equations is used. Numerical results of established program are compared with experimental results. This work uses also the Fluent software to calculate transonic flows. Numerical results calculating from the established program and .