关键词: 液体火箭发动机;换热器;压力脉动;两相流;非线性分析

Abstract: Pressure pulsation in oxygen heat exchanger of a hydrogen-oxygen rocket engine is detected in development stage， which has an adverse influence on the performance of the exchanger. The heat exchanger is divided into gas side， collecting pipe， round tube and other structures， and CFD simulation calculation is carried out. Compared with the test results， the heat transfer related parameters are corrected， and theoretical calculation model is established for parameter calculation. The non-linear method is used to analyze the experimental data and the heat exchanger is determined to be a chaotic system. The two-phase flow analysis and circuit analogy are used to model and calculate the heat exchanger respectively. The pressure pulsation in the heat exchanger under the phase change is captured. The results show that the parameters corrected by CFD simulation and experiment are consistent to calculate the steady-state parameters of the heat exchanger. When the pressure pulsation of the heat exchanger occurs， it has certain non-linear characteristics， and the greater the pressure pulsation， the higher non-linearity is. The reason for the pressure pulsation of the heat exchanger is that the oxygen condition is close to the two-phase region， and the phase change makes the density change drastically. According to the analysis results， the designed pressure of exchanger increases as an improvement measure， which has been verified by test.

Key words: Liquid rocket engine;Heat exchanger;Pressure pulsation;Two-phase flow;Non-linear methods