Numerical Analysis Of Overload And Spinning Effect On Two-phase Flow Field In SRM

Solid rocket motors are widely used in the power systems of advanced tactical missiles.Due to the use of aluminum-containing composite propellants,a large amount of Al₂O₃ is generated in the combustion products to form a typical two-phase flow.Combustion and two-phase flow exist in the engine working process at the same time.In the middle,the interaction between the two will make the work process extremely complicated,especially inducing ablation of the thermal insulation layer,mechanical erosion of the particles against the thermal insulation layer,unstable combustion,erosion effects,thermal protection failure,and pillar structure.Such as poor integrity and weak shell strength.At present,tactical missiles require high maneuverability.The missiles will have different degrees of overload during acceleration and maneuvering.Flight overload will affect the structure of the flow field,change the particle movement state in the combustion chamber,and cause the particles to accumulate in the bearing direction and deteriorate.The working environment of the thermal insulation layer,in severe cases,can lead to thermal protection failure and even cause the projectile to burn through.In this paper,the SRM overload is taken as the research object,and numerical simulation method is used to study the influence of rotation and overload on the two-phase flow field in the solid rocket motor.Firstly,the state of no-rotation and no-load solid rocket motor is taken as the basic working condition.Then,the transverse orbital,axial overload and combined overload are calculated by using the particle orbit model,and the three-dimensional and two-phase flow of the solid rocket engine combustion chamber and nozzle is established.Simulations have analyzed the effect of overload on the particle phase.Then,the engine under high-speed rotation was calculated and the effect of rotation on the particle concentration distribution of the engine was studied.Analyze the above simulation results to preliminarily analyze the particle aggregation and overload rules.At the same time,the low rotation speed and the medium and small overloads are added at the same time,and the change of the particle aggregation position and the aggregation amount is compared.The results show that in the presence of a lateral acceleration load,the concentration of the particulate phase in the engine combustion chamber in the load-bearing direction increases,significantly changing the original axisymmetric flow state in the engine combustion chamber,and the maximum concentration region of the particle-condensing flow in the bearing direction is mainly Distributed in the rear head of the engine,with the submersible section.Axial overload will increase the particle concentration of the sneak-in and back-end heads of the nozzle,and has the most significant effect on the particle concentration at the interface between the sneak-in and back-wall regions.When the lateral overload is less than 10g,the proper rotation speed can relieve the problem of particle deposition on the surface of the thermal insulation layer.When the lateral overload is 20g,the rotation will increase the degree of particle aggregation on the bearing surface,which is not conducive to ease the severe ablation in the combustion chamber surrounding.