Numerical Simulation Of Flow Field And Heat Transfer In Annular Slot Of Conic-Column Grain

Annular slots exist at the front and aft end of conic-column grain. The igniting gas flows at different inflow conditions influence the flow-field and temperature distribution in the annular slot. Then this affects the heat transfer between the hot gas and the grain surfaces. Finally, it influences the pyrogenation of the solid propellant. In order to study the behaviors of the igniting gas flow in the slot, CFD software Fluent6.2 was employed in this thesis to investigate the flow field in the forward and backward annular slots of the two-dimensional axisymmetric conic-column grain and the heat transfer between the hot gas and grain surface. The main contents are as follows :(1) the standard k -εturbulence model and DTRM were employed to study the flow field and heat transfer in the forward and backward annular slots; (2) the standard k-εturbulence model was used to investigate the convection in the forward and backward annular slots;(3) the Reynolds stress model was used to study the influence of the swirl number on the flow field and heat transfer in the forward annular slot and the RNG k-εmodel was used to study the influence of the swirl number on the flow field and heat transfer in the backward annular slot;(4) the mixture model and standard k-εturbulence model were employed to study the volume fraction distribution of the solid phase in the annular slot. Following assumptions were assumed during the calculations. The flow field was time-independent and the density of the gas was constant. The results indicate that the heat transfer increases as inflow Reynolds number increases. But the ratio of the radiation flux per square area to the total heat flux per square area varies differently in different surfaces. The volume fraction distributions of the solid phase in forward and backward slots were closely related with the flow field in the annular slots. The results presented in this thesis can be a reference for grain design.