半物理试验起动阶段低温燃油流量计量技术路径探究

针对装备数控系统的2个型号发动机分别在台架试验和飞行试验中发生的低温起动失败故障，从数控系统半物理试验燃油流量计量宽范围、快响应、高精度的测量要求入手，分析了试验的测量环境与涡轮流量计检定条件要求的环境存在的较大差异，在低温条件下燃油黏度提高，造成了流量系数减小，试验室测量流量示值小于实际流量，低温燃油流量测量准确度存在不可接受的偏差；阐述了发动机低温起动失败故障时供油不足，不能通过当前的流量测量方法进行确认和故障定位，提出了解决高响应低温小流量测量技术问题的研究路径及关键技术的方案和思路，主要方案和思路有：质量流量计串联标定法、常温涡轮流量计串联标定法、体积管串联标定法。

Measurement Technology of Fuel Flow under Low Temperature Starting in Semi-physical Test

Aiming at the failure of low temperature start that happened respectively in rig and flight test for two types of aeroengine with digital control systems, the measurement requirements such as wide range, fast response and high accuracy of fuel metering during semi-physical test applied to digital control systems were described. The significant differences between the measuring condition and the factual condition in the verification process of turbine flowmeters were analyzed. The increase of fuel viscosity in the condition of low temperature caused the reduce of flow coefficient which resulted that the indicated value of measured flow rate in test was less than the actual flow rate and unacceptable deviation appeared in measurement accuracy of low temperature. It was stated that the fault of low temperature start was caused by insufficient fuel supply and thus were unable to identify and locate. Some ideas of research route and key technology schemes were proposed to address the issue of technology validation of high response, low temperature, and low flow rate measurement. which mainly are the connection series of mass flowmeters, thrmostatic turbine flowmeters and volume tube calibration device.