Research On Deposition Effect Identification And Thrust Prediction Method Of The Solid Divert And Attitude Control System

Solid Divert and Attitude Control System(SDACS)is a direct force control system of modern kinetic energy weapons,and it is also one of the key technologies for improving the combat performance of tactical missile weapon systems in the future.The SDACS usually changes the magnitude and direction of the thrust vector by multinozzle coupling to realize the rapid orbit change and attitude adjustment.The thrust of the motor changes in real time according to the movement of the valves.The equivalent throat area of the engine is adjusted with the relative position of the pintle and nozzle,and it has effect on the mass flow rate and thrust.At present,there is a large deviation between the theoretical thrust and the actual thrust of the engine in the engineering research.This paper researches the deposition effect identification and thrust prediction method of SDACS,which can effectively solve the problem of accurate thrust prediction.Research on the experiment design method of the pintle motion scheme of SDACS.A sequential experimental design method is proposed to design the pintle motion scheme,which is overcome the limitation of the manual pintle motion scheme and the inability to traverse all possible thrust combinations in engineering.Multi-factor and nonlinear problems that cannot be overcome by engineering experience alone.Based on the calculation model of the internal ballistic performance of the attitude and orbit control engine,considering two typical working states of the three working sections,the mathematical model is used to characterize the movement process of the laryngeal plug,the spatial uniformity criterion is selected as the objective function to evaluate the uniformity of the sampling point distribution,and the adaptive Particle swarm optimization optimizes the objective function to the minimum.Realize the maximum ratio of thrust combination obtained in a single test,ensure the validity of the test data,and reduce the consumption of test resources and time.An identification model for the deposition effect of the nozzle and pintle of the SDACS is established,and the deposition law under different conditions was obtained.Considering the deviation of the engine thrust caused by the deposition effect,a calculation method of internal ballistics considering the deposition effect is proposed.The pintle bus and the nozzle bus are represented as mathematical models,and the equivalent throat area of the engine is solved by the nested dichotomy.The single-step update and iterative calculation of the actual equivalent throat area during engine operation.Study the factors affecting the deposition of engine nozzles,establish a deposition ash box model,use particle swarm algorithm to identify unknown parameters,and obtain the actual equivalent throat area after the deposition of each valve with the movement of the throat plug.Consider the nozzle and throat plug respectively.In the case of different deposition efficiencies,the deposition law of the engine is obtained.Substituting the obtained identification parameters into the model for zero-dimensional internal ballistic calculation,the root mean square error between the identification pressure and the actual pressure is small,and the goal of accurately identifying the sedimentary model parameters is achieved.A rapid prediction method of actual thrust under the influence of sedimentation effect is proposed.According to the throat plug displacement and combustion chamber pressure conditions under different valve deposition amounts,the nozzle deposition volume,throat plug deposition volume,throat plug displacement,and combustion chamber pressure are selected as design variables,and the actual thrust of the engine is obtained by CFD.Aiming at the complex and time-consuming CFD calculation process,an approximate modeling method combining local density and fast cross-validation is proposed to establish an accurate and fast prediction model of the actual thrust of the engine.Propose a shape parameter characterization method based on the local density of the sample,transform the complex domain optimization problem of multiple shape parameters into a univariate optimization problem of the scaling factor determination,and propose a universal fast K-fold cross-validation algorithm to determine the scaling factor reasonably,and derive a general crossover In the process of verifying error solving,high-order matrix fast inversion and cross-validation error fast solving formulas reduce the computational complexity of determining the shape parameters of the radial basis function.Based on the research work in this paper,the high-precision and rapid prediction of engine thrust is completed,and the deviation from the simulation result is controlled within 0.6%,which greatly reduces the loss of computing resources and greatly improves the work efficiency.The method proposed in this paper has been verified by theoretical research and numerical examples,and is both accurate and practical,and has high engineering application value,laying a good technical foundation for the thrust accurate prediction and control of SDACS.