基于正交设计方法的气缸盖上水孔流量测量技术

Flowrate Measurement of Upper-nozzles in Cylinder Head Based on Orthogonal Design Method

采用正交设计方法,通过数值模拟手段,研究了各结构参数及安装参数对测量误差的影响。为把由结构参数及安装参数引起的测量误差控制在设定范围3%内,对模拟结果进行了极差分析,通过多轮极差分析及各因素的水平范围优化,获得了把测量误差控制在3%以内的结构参数和安装参数的允许变化范围,确定了可行的测量装置加工和安装方案。最后,进行了模拟方案的实验验证,验证结果表明,模拟误差与实验误差的偏差为2.07%,验证了数值模拟的可信性,同时也确保了测量技术的准确性。

With the improvement of power density of internal combustion engine,the coolant jacket structure is becoming more and more important.The design and optimization of coolant jacket depend heavily on the construction and position of the upper-nozzles,so that the flowrate measurement in the upper-nozzles will benefit those design and optimization.However,during the flowrate measurement,the construction parameters and installation parameters of the measurement rig will affect the measurement error significantly.This paper explored the relationship between these parameters and the measurement error by means of CFD numerical simulation based on orthogonal design method.In order to control the measurement error in 3%,the flow in many upper-nozzle schemes were simulate,and then the range analysis of the simulation results were achieved and the levels of each factor were optimized.After the optimization,the suitable levels of each factor were determined,and the maximum measurement error of the optimum schemes was reduced to 2.95%.At the end,the paper achieved a measurement experiment to correct the numerical simulation,and the difference between simulation error and experimental error was only 2.07% according to the experimental results,which verified the reliability of the numerical simulation and accuracy of the measurement technology.