自然风条件下露天试车台推力修正的数值模拟研究

Numerical Simulation Study on Thrust Correction for Outdoor Test Stand in Natural Wind

关键词:  航空发动机  露天试车台  自然风  数值模拟  推力修正

Key words:  Aero-engine  Outdoor test stand  Natural wind  Numerical simulation  Thrust correction

摘要:

为研究自然风下露天试车台航空发动机推力修正的方法，针对典型结构露天试车台开展航空发动机在不同自然风风速（0~5m/s），风向（0~90°）下试车流场的数值仿真研究。研究发现，自然风条件明显影响露天试车发动机进气道周围回流区的分布，以往基于测量二次气流的室内试车台推力修正方法无法用于露天试车台，因此推导出基于发动机内流参数的进气附加阻力计算和测量方法，并结合仿真结果分析不同自然风对露天试车台各阻力修正量的影响。结果表明，对于进气附加阻力，随着风速增大逐渐成正比例增加，最大占总推力1.09%；对于台架迎风阻力，当风向角小于45°时与进气方向风速之间满足近似二次曲线关系，最大占总推力0.18%；无风时由于发动机排气射流对台架周围气流速度的影响，仍有台架迎风阻力。

Abstract:

In order to study the thrust correction method on the outdoor test stand of aero-engine， numerical simulation calculations of aero-engine test in the open-air under different natural wind speed （0~5m/s） and wind direction （0~90°） were carried out. It is found that the natural wind conditions obviously affect the distribution of the backflow area around the engine air-inlet on the outdoor test stand. The thrust correction method used in the indoor test cell based on measuring the second flow traditionally cannot be appropriate for the outdoor test stand. Therefore， a method for calculating and measuring the intake additional drag based on the internal flow parameters of the engine was derived. Combining the simulation consequence， the influence of different natural wind on each drag correction amount of the outdoor test stand was analyzed. The results show that with the increase of wind speed， it gradually increases proportionally and accounts for 1.09% of the total thrust for the additional drag of the intake air. For the windward drag of the stand， it satisfied the approximate quadratic curve relationship between the wind direction angle and the wind speed in the intake direction when the wind angle is less than 45° and accounts for 0.18% of the total thrust. When there is no wind， there is still windward drag of the stand due to the influence of the engine exhaust jet on the airflow velocity around the stand.