Purpose

Abnormal vibrations often occur in the liquid oxygen kerosene transmission pipelines of rocket engines, which seriously threaten their safety. Improper handling can result in failed rocket launches and significant economic losses. Therefore, this paper aims to examine vibrations in transmission pipelines.

Design/methodology/approach

In this study, a three-dimensional high-pressure pipeline model composed of corrugated pipes, multi-section bent pipes, and other auxiliary structures was established. The fluid–solid coupling method was used to analyse vibration characteristics of the pipeline under various external excitations. The simulation results were visualised using MATLAB, and their validity was verified via a thermal test.

Findings

In this study, the vibration mechanism of a complex high-pressure pipeline was examined via a visualisation method. The results showed that the low-frequency vibration of the pipe was caused by fluid self-excited pressure pulsation, whereas the vibration of the engine system caused a high-frequency vibration of the pipeline. The excitation of external pressure pulses did not significantly affect the vibrations of the pipelines. The visualisation results indicated that the severe vibration position of the pipeline thermal test is mainly concentrated between the inlet and outlet and between the two bellows.

Practical implications

The results of this study aid in understanding the causes of abnormal vibrations in rocket engine pipelines.

Originality/value

The causes of different vibration frequencies in the complex pipelines of rocket engines and the propagation characteristics of external vibration excitation were obtained.

中文翻译：

---

火箭发动机流道振动特性研究

目的

火箭发动机液氧煤油传输管道经常出现异常振动，严重威胁其安全。处理不当可能导致火箭发射失败和重大经济损失。因此，本文旨在研究传输管道的振动。

设计/方法论/途径

本研究建立了由波纹管、多节弯管及其他辅助结构组成的三维高压管道模型。采用流固耦合方法分析管道在各种外部激励下的振动特性。使用 MATLAB 将仿真结果可视化，并通过热测试验证其有效性。

发现

在这项研究中，通过可视化方法检查了复杂高压管道的振动机制。结果表明，管道的低频振动是由流体自激压力脉动引起的，而发动机系统的振动引起了管道的高频振动。外部压力脉冲的激励并没有显着影响管道的振动。可视化结果表明，管道热工试验振动剧烈的位置主要集中在进出口之间以及两波纹管之间。

实际影响

这项研究的结果有助于了解火箭发动机管道异常振动的原因。

原创性/价值

得出了火箭发动机复杂管道中振动频率不同的原因以及外部振动激励的传播特性。