Numerical Simulation Of Internal Flow Field In High Pressure Turbine

Water reaction high pressure turbine has very high energy density and high working temperature due to the use of hydroreactive metal fuel.so it needs to be cooled with water to reduce the temperature of the working fluid.Therefore,gas-solid two phase flow occured in the flow field of turbine,and the flow is very complicated.At the same time,the water reaction high pressure turbine designed in this paper has a relatively large expansion,and the flow velocity in the flow path of the turbine is very high up to supersonic flow.Therefore,the internal flow is very complicated and it is necessary to research the flow field in the flow path of the water reaction high pressure turbine.First of all,according to the unidimensional flow theory of the impeller mechanical,the turbine used in this paper is designed.The nozzle and rotor of the turbine are Laval nozzle and impulsive high-load blade,respectively,using partial admission method.The FLUENT software was used to research the flow of gas in the pure gas-phase flow field in the flow path of the turbine.The research focused on the flow of two nozzles of the turbine,the circumferential inhomogeneity of the air flow,the flow and loss mechanism of the airflow intake and non-intake arcs of the flow and the workability of each blade,the results are compared with the theoretical results to verify the accuracy of the model and the algorithm used in the numerical simulation.Then,the discrete phase model model of FLUENT software was used to simulate the gas-solid two phase flow field of Water reaction high pressure turbine.The difference between the flow field and the pure gas flow field after the introduction of Al₂O₃ particles was analyzed.The research focused on the particle size and particle mass fraction of the turbine power and efficiency and the effect of passing Al₂O₃ particles on the flow field of the turbine.Finally,variable operating characteristic investigation in the turbine was investigated by theoretical analysis.The variation of the characteristic parameters of the turbine under non-design conditions was obtained without Al₂O₃ particles.The numerical simulation was used to research the influence on the power and efficiency of the turbine when the total inlet pressure of the nozzle,the static pressure at the outlet of the rotor,the total temperature at the inlet of the nozzle and the speed of rotation were changed.