Optimization design method for structural parameters of solid rocket engine jet pipe

Abstract

The invention discloses an optimization design method for structural parameters of a solid rocket engine jet pipe. The optimization design method comprises the following steps: 1, constructing a material thermophysical parameter model of each component of the jet pipe through a segmented cubic Hermite interpolation method; 2, constructing a thermal boundary condition model of the inner wall of the spray pipe through a Lagrange interpolation method; 3, analyzing and considering the temperature distribution and the thermal failure stress of the nozzle in the complex environment of interface debonding through a complete thermal coupling finite element method or a sequential thermal coupling finite element method; and 4, calculating peak values of thermal stress curves of the nozzle in working time under different axial lengths of the expansion section and different inclination angles of the contact surface of the expansion section and the throat liner, and obtaining the relationship between the maximum thermal stress value of the nozzle and the axial height of the expansion section and the inclination angles of the contact surface of the expansion section and the throat liner for structural optimization of the solid rocket engine nozzle. According to the method, the parameter selection and design of the nozzle structure can be optimized while the thermal stress extreme value of the nozzle is effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of solid rocket motors, and in particular relates to a thermal-mechanical coupling analysis method and a structure optimization design method of a nozzle structure of a solid rocket motor. Background technique [0002] The solid rocket motor is a power device for space launch vehicles and strategic missiles that uses solid propellant. It burns in the combustion chamber through the solid propellant to generate high-temperature gas. The speed of sound is accelerated to supersonic speed, and after passing through the converging section and throat lining, it is ejected into the surrounding environment through the expanding section to generate a driving force, realizing the transformation from chemical energy to kinetic energy. During the working process of the engine, the nozzle is subjected to a gas temperature of nearly 3400 ° C and a huge pressure, and there is erosion and corrosion of chemical particles, so ...

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Problems solved by technology

[0004] 1. For the uncertainty of thermodynamic and physical properties of composite materials under high temperature conditions, there is no effective method to determine the characteristics of nozzle material properties changing with temperature;

[0005] 2. The treatment of the interface problems of the nozzle is oversimplified, and it is considered to be in a firm bonding state all the time. However, under certain conditions of high temperature and shear force, the adhesive layer slips between layers and does not transfer forcefully. Considering the problem of interface debonding and adhesive layer softening failure, it will cause large calculation errors;

[0006] 3. Failure to consider the contact state of the nozzle before and after interface debonding occurs during the working time, resulting in deviations in the calculated thermal stress extreme value position and errors in the thermal stress extreme value;

[0007] 4. The existing correlation analyzes all use the sequential coupling analysis method to calculate the thermal stress of the nozzle. There is no comparison between the complete coupling analysis method and the sequential coupling analysis method. When the interaction between temperature gradient and stress is not considered, the sequential coupling method is used will cause calculation errors;

[0008] At present, there are few optimization design methods for nozzles combined with the extreme value of thermal damage stress. In order to reduce the extreme value of thermal stress of the nozzle during working hours and improve the safety and reliability of the nozzle, how to effectively select and optimize the geometric parameters of the nozzle Waiting for no public report

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