Optimization Method of Key Structural Parameters for Reliable Motion of Engine Exhaust Nozzle

Abstract

The invention discloses a method for optimizing the motion flexibility and reliability of an engine composite tail nozzle, comprising steps: the first step, analyzing important parameters affecting the motion flexibility and reliability of the tail nozzle, and determining the optimization object; the second step 1. Confirm the numerical range of each optimization object parameter, and carry out follow-up optimization for this range; the third step is to formulate the engine exhaust nozzle motion performance evaluation index and stress damage failure index; the fourth step is to establish the impact of composite material exhaust nozzle Dynamics simulation, optimize the simulation calculation of each parameter; the fifth step, by analyzing the influence trend of each parameter on the movement flexibility and reliability of the tail nozzle, put forward the composite material tail nozzle pin hole matching unilateral clearance, surface friction Suggested indicators for parameter selection for coefficients and driving air pressure. The invention solves the problems of low movement flexibility and easy failure of the tail nozzle, and realizes the improvement from sensory experience to theoretical method, from qualitative exploration to quantitative optimization.

Description

technical field [0001] The invention belongs to the field of optimization and simulation of engine tail nozzles. More specifically, it relates to a reliable motion optimization method for a convergent-expanded composite engine nozzle. Background technique [0002] The tail nozzle is an important part of the engine, and its main function is to obtain forward thrust by ejecting the high-temperature airflow backwards. According to whether the nozzle is fixed, it can be divided into adjustable tail nozzle and non-adjustable tail nozzle. The adjustable tail nozzle can adjust the nozzle flow. According to the variation of the cross-sectional area, the adjustable tail nozzle is divided into the convergent type and the convergent expansion type. Among them, the convergent expansion type adjustable tail nozzle is widely used in the engines of advanced fighter aircraft and missiles due to its good supersonic performance. middle. The characteristic of the converging and expanding t...

AI Technical Summary

Problems solved by technology

In order to withstand high temperatures, its parts are mostly made of FRCMCs materials, which have the characteristics of high hardness, high brittleness, and poor processing performance, which makes the tail nozzle parts have large machining errors and poor surface quality. When shrinking, there are problems of slow speed and poor flexibility; when the pneumatic drive reaches the limit position of shrinkage, it is easy to generate a large impact load at the key assembly connection position, causing high local stress on key parts and even damage and failure, seriously affecting the tail nozzle reliability

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