Numerical analysis of nozzle and free-jet flows of particle mixtures

A numerical analysis of nozzle and free-jet flows of gas-particle mixtures is described. The National Space Development Agency of Japan (NASDA) plans to develop a satellite launcher called the H-II. For the basic design of the H-II rocket, thermal protection of the rocket wall against strong heating due to thermal radiation from the jet exhaust from the nozzles is considered to be important. The thermal emissivity of solid particles is by far larger than that of gas for typical firing conditions of rocket engines with solid propellants. Therefore, the determination of flow field of the particle-phase in the jet-plume is especially important. In the present calculation, the two-step MacCormack algorithm is used for the gas-phase flow and the method of characteristics is applied to the particle-phase flow. Thus the present numerical algorithm is a mixed algorithm. To investigate and confirm the accuracy and the reliability of the numerical results, another mixed scheme consisting of PLM (Piecewise Linear Interpolation Method) for the gas-phase flow and the method of characteristics for the particle-phase flow is also applied. The numerical results obtained by these two methods are compared with each other.