管内气体流动的多参数动态数学模型的建立

由于从飞机发动机中引出气流的不稳定流动，对飞机空调系统的精确调节有很大影响。根据气体流动的基本定理，一种适用于小管径、多变量输入输出的可压缩气体管内流动的动态数学模型已在本文推导出，并采用频域和时域方法对数学模型进行了分析。研究结果表明：当气体的入哭喊和波频率上升到一定值时，出口压力将急剧上升。流量的变化对出口压力影响最大。入口温度的变化对出口压力和流量有影响，但入口压力和流量的扰动对出口温度没有

ESTABLISHMENT OF DYNAMIC MATHEMATICAL MODEL OF MULTI VARIABLE SYSTEM FOR COMPRESSIBLE GAS FLOWING IN PIPE LINE

The precise adjustment of the airplane air conditioning system is influenced much by the unstable flowing of gas out from airplane engine .According to the fundamental law of gas flowing ,the dynamic mathematical model of multi input and multi output system suitable for compressible gas flowing in small diameter pipe line has been conducted.It has been analyzed by means of frequency and time method .The research result shows that the outlet pressure rises rapidly when the frequent of the inlet pressure rises to a high value.It is of the greatest that the influence of the outlet pressure by the rate of flow.The outlet pressure and rate of flow is influenced by temperature,but the outlet temperature isn't influenced by the inlet pressure and the rate of flow.The step response of temperature shows that the outlet temperature rises sharply after a short time and the adjustment time of the flowing process is very short.