基于IDMS的航空发动机砂尘吸入物定量监测

针对航空发动机砂尘吸入物定量监测的问题,提出了基于进气监测系统(IDMS)的砂尘吸入物质量浓度监测及总量估算方法。借助ANSYS电磁场仿真软件建立了IDMS系统有限元模型,实现对发动机实际工况下的砂尘吸入物的静电场模拟,研究确定砂尘吸入物质量浓度、荷质比等宏观参数与IDMS监测信号的关系。研究发现所建立的IDMS有限元模型获得的传感器特性与前期试验获得的结论一致,静电信号随吸入颗粒物浓度的变化与试验中实测信号的变化趋势一致,为基于IDMS信号的砂尘吸入物定量监测和评估提供理论依据。仿真试验表明,荷质比一定的情况下IDMS感应电荷量与砂尘浓度呈线性增长关系,通过IDMS感应电荷信号可实时监测发动机砂尘吸入物质量浓度,并可进一步累积估算一段时间内砂尘吸入物总量,最终总量估计误差不超过4%。

IDMS based method for quantitative monitoring of aero-engine ingested airborne sands

In order to monitor the ingested airborne sands inside the aero-engine quantitatively,this paper builds the simulation model based on ingested debris monitoring system (IDMS) to analyze different ingested airborne sand distributions and also proposes the method for estimating the total amount of ingested airborne sands,based on the IDMS signal.IDMS model is developed in finite element software ANSYS to simulate the electrostatic field of ingested airborne sands with electrostatic charges.The relationship between the IDMS monitoring signals and the parameters of the ingested airborne sands is studied,such as mass concentrations and charge-to-mass ratio.The IDMS sensing characteristic derived from the finite element model proposed is found to be consistent with the results of previous experiments.The trend of electrostatic signals from both simulation and experiment are the same,laying the basis for the monitoring of the mass concentrations of the ingested air borne sands as well as the estimation of total amount.This simulation study shows that the relationship between induced charges of IDMS and mass concentration is linear,given a constant charge-to-mass ratio.The induced charges along with different ingested airborne sand distributions can be extracted from real-time monitoring system.Therefore,based on the measured charge signals using the IDMS,the mass concentrations of the ingested airborne sands can be recorded on-line,and further the total amount of airborne sands ingested during a specified interval can be estimated with an estimation error no greater than 4 ％.