IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 11, 2017 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 446 Comparison of Supersonic Nozzles in Different Outlet Divergence Angle using CFD Jyoti Kumari 1 C. S. Koli 2 1 M.Tech Scholar 2 Professor 1,2 Department of Mechanical Engineering 1,2 SRCEM Banmore Abstract— The comparative flow analysis on the supersonic nozzle has been performed by this experiment. The experiment is done with same parameters like inlet, outlet and length of nozzle but different throat angles. The first throat angle or outlet divergent angle is 10°and second outlet divergent angle (throat angle) is 20°. The experiment has been set on the two prefatory steps. Modelling and CFD analysis are including and after that comparing their different properties of the nozzle. The two dimensional axisymmetric supersonic nozzles were drawn in design modeler of ANSYS WORKBENCH 14.5 and CFD analysis is done on the fluent. The cross sectional area of inlet and outlet are same, throat area and nozzles length are exactly same. At the end of this experiment, analyzing the velocity, pressure, temperature behavior on the nozzles and to take final results. Key words: CFD, Supersonic Nozzles I. INTRODUCTION The output velocity of fluid is basically depend upon the inlet and outlet convergence angle of CD nozzle. This paper representing the most relevant numerical analysis of flowing of fluid to outlet convergence of supersonic nozzle with two aspect: with outlet divergence angle at 10° and 20° of the supersonic nozzle. The fluid entered in the nozzle with 2 bar pressure and flow outlet with 10° and 20° through with outlet of nozzle by governing the nozzle equation and finally outcomes are validated with the help of ANSYS CFD WORKBENCH 14.5. II. THEORETICAL FORMULATION OF SUPERSONIC NOZZLE A. Governing Equcation: After the modeling is completed the meshing is to be done. We are using a fluid fluent module for performing a meshing. Automatic method is using here for meshing and the mesh type is selected as all quad. In study of any fluid flow we basically concern about three basic principle: 1) Conservation of mass 2) Conservation of momentum 3) Conservation of energy Then we are also considering the Navier- Stroke equation. For Steady flow neither two nor three dimensional fluid flow, the continuity equation becomes:  ௫ ሺሻ +  ௫ ሺሻ = 0 ……..equ.1 For compressible flow, the momentum equation for the x- direction becomes  ௨ ௫ +  ௨ ௬ = −  ௫ +  ௫ {2 ௨ ௫ }+  ௬ ሺ  ௬ + ௩ ௫ ሻ ……..equ.2 And for y- direction the equation becomes  ௨ ௫ +  ௬ ௬ = −  ௬ −  +  ௫ ቀ [ ௩ ௫ +  ௬ ]ቁ +  ௫ ቀ2 ௩ ௬ ቁ ……..equ.3 The momentum equation are also called Navier- stroke equation. The energy conservation equation for the fluid neglecting viscous dissipation. ∁  ቀ  ௬ +  ௬ ቁ=  ௫ ቀ  ௫ ቁ+  ௬ ቀ  ௬ ቁ ………equ.4 In these equation u and v are the velocity components in x and y direction, ρ is the density, T is t he temperature is thermal diffusivity, μ is the viscosity, C_p is specific heat at constant pressure. Second order equation of velocities in x- direction, velocity in y-direction continuity, K (turbulent kinetic energy) Epison turbulent dissipation rate are considered in converging the solution. Comparison between supersonic nozzles with same data at 10° outlet divergence angle of nozzle B. Nozzle Dimensions: Inlet radius 30 mm Nozzle Length 200 mm Throat length 10 mm Ideal gas viscosity Sutherland C. Boundary conditions: 1) Inlet 2) Outlet 3) Walls To giving a boundary condition has to be done in ANSYS WORKBENCH. There is no possibility to given a boundary condition in FLUENT. Due to this boundary condition, its easily found and analysis of flow rate. The meshed file is read in Fluent to solving the problem. Inlet: The fluid flow is entering through inlet of nozzle. The inlet diameter of nozzle is 20mm. the effects of stress concentration in term of pressure, temperature, velocity and various parameter are analyzing when fluid flow entering in the nozzle. Outlet: The fluid flow is exit from the outlet of nozzle. The outlet diameter of nozzle is 30mm. the effects of stress concentration in term of pressure, temperature, velocity various dimension are observed when fluid is flowing towards to outlet and totally exit from the outlet of the nozzle. Walls: when fluid is flowing in the nozzle, the fluid is strikes on the walls of the nozzle. Throughout the nozzle when it’s flowing the fluid are making the velocity profile. With the help of velocity profile the minimum and maximum effect of stress on the walls but this effects of stress is not same to whole nozzle walls.