Figure 2: Converging-Diverging Initial conditions For our study on the nozzle, we will consider the following conditions: Figure 1: Converging-Diverging Nozzle In this part, we will be studying the lower part of the rocket. In fact, the study will concern the supersonic converging-diverging nozzle. The main idea is to compare the results to the experimental ones made on fluent. As we can see in the figure below, here are the dimension’s assumptions made on the nozzle: Figure 4: Pressure ratio graph Figure 5: Range of back pressure Figure 6: Total pressure isentropic flow On this part, we will realize the nozzle on Ansys with right dimensions. Then, the work will be to fine the mesh of the nozzle to obtain good results as it’s an important factor. Finally, the study of the flow will be on fluent using the initial conditions presented before. Figure 7: Static Pressure Isentropic flow If the error less than 5 % it means that the analytical result match well with the experi- mental ones. Figure 8: Mach number isentropic flow Figure 9: Analytical results Figure 10: Static pressure Normal shock To do the experimental part, we considered the density based for a compressible deal gas. After running the calculations on 2000 iterations we obtain the following results: Figure 11: Total pressure Normal shock Figure 12: Mach Number Normal shock Comparison part Comparing the Mach number between the analytical result and the CFD we obtain: Figure 14: Analytical results Figure 15: Mach Number Oblique shock For the experimental part, by putting a back pressure of 1 MPa which is included n the range of back pressure to obtain an oblique shock wave we have the following result: Figure 17: Mach Number Normal shock Below the analytical calculations for the expansion wave. The Theory calculations were made on excel based on the formulas, the isentropic and the Prandtl-Meyer flow table: Figure 18: Mach Number Expansion For the experimental part, by putting a back pressure of 35000 Pa which is included in the range of back pressure to obtain an expansion wave we have the following results: Figure 19: Total pressure Expansion Figure 20: Static Temperature Expansion Figure 23: Rocket design for CFD To study the upper surface of the rocket we will consider the following rocket: (the dimensions are in m) Note: The above dimensions are in m Oblique shock on the upper surface of the rocket Figure 24: Analytical results Figure 25: Mach Number on the upper surface of the rocket For this experimental part, we will create a far field considering a compressible ideal gas with operating conditions equal to 0. Figure 26: Static Pressure on the upper surface of the rocket Figure 27: Static temperature on the upper surface of the rocket Figure 28: Velocity magnitude on the upper surface of the rocket Figure 29: Total pressure on the upper surface of the rocket Figure 30: Total temperature on the upper surface of the rocket By using the symmetry, we can obtain this contour with clear oblique shock waves: Figure 31: Overall velocity magnitude on the rocket design (by symmetry) 6.3 Comparison part
