| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 90 === In this study of numerical simulation is used to investigate the flow properties and thrust angles of two-dimensional thrust-vectoring nozzles with different shapes. The geometric segments of these convergent-divergent nozzles are also analyzed. Using a WENO Scheme and a 4th-order Runge-Kutta method, the two-dimensional compressible Euler equations are solved. The configuration of the investigated nozzles includes A1 (0°)、A1V10 (9.79°)、A1V13 (13.22°) and A1V20 (20.26°).
First, we consider an ideal gas, Inviscid flow and viscous flows with laminar and turbulent models are calculated. In viscous flow calculation, we find that viscous-flow result is very close to that of inviscid flow and of experimental data. Namely, the viscous effect has no influence on vectored thrust. Thus, we use inviscid-flow model to investigate the 2D thrust-vectoring nozzles with ideal- and real-gas effects. Next, we consider a real gas to the effect of real gas. We also discuss the grid, specific-heat ratio and temperature effects on the numerical solution. In addition, we design two testing types called TEST-V07 and TEST-V16, which have thrust angles of 7°and 16° respectively. Ti is found that the computed thrust angles are good agreement with the design condition. The boundary condition of wall is adiabatic and reflected.
The predicted thrust angles are compared with experimental data. It is found that the computed result is well agreed with the existing data. Moreover, the flow field behind the throat is prominently changed with the sonic line position. In an ideal operation, the nozzle pressure ratio (NPR) greater than 4.0 has little effect on the nozzle flow field, and the thrust performance with turning losses is increased with the thrust angle.
It is found that the increase of inlet Mach number from 0.4749 to 0.85, the thrust-vectoring angle is almost not changed, but the total thrust increased about 14% and about 2% for specific impulse. By decreasing the inlet temperature from 4200K to 1300K (NPR=Pt/Pe=4.0), the thrust-vectoring angle is increasing about 2%, 3% for the total thrust and 50% for specific impulse. Therefore, it is concluded that the effect of the inlet temperature is greater than that of the inlet Mach number.
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