气动量仪测头流场对发动机连杆测量稳定性的影响分析  

Analyzing Influence of Flow Field of Pneumatic Measuring Instrument on Measurement Stability of Engine Connecting Rod

作　　者：魏先杰 龙威[1] 邓伟 王继尧 吴蜜蜜 WEI Xianjie;LONG Wei;DENG Wei;WANG Jiyao;WU Mimi(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;Yunnan Xiyi Industrial Co.,Ltd.,Kunming 650114,China)

机构地区：[1]昆明理工大学机电工程学院,昆明650500 [2]云南西仪工业股份有限公司,昆明650114

出　　处：《机械科学与技术》2021年第3期428-434,共7页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金重点项目(51766006);云南省教育厅科学研究基金项目(2021Y113);学生课外学术科技创新基金项目(2020YB048);清华大学摩檫学国家重点实验室开放基金项目(SKLTKF16B02)。

摘　　要：现有气动量仪在使用过程中出现测量数值不稳定、工件测量磨损等现象。本文分析了气动量仪测量工作原理,对发动机连杆大头孔与大头测头之间的内部流场进行了数值计算和实验测量,发现现有连杆测头的导向面没有形成有效支撑气膜,且在排气槽中气流紊乱,导致测量过程稳定性差,喷嘴端面附近的排气槽边缘会产生局部高压区,导致气阻增大,从而影响测量精度,从而明确了气动量仪测量过程中气膜流场均匀性对测量稳定性的决定性作用。提出了测量稳定性和可靠性更好地双E型排气槽结构测头,通过分析双E型测头内部流动特征,采用双E型排气槽结构测头的压力和流场分布更均匀,气流波动收敛至稳定值,测量波动幅值是现有测头的1/5,有效提高了的测量精度和测量稳定性。The existing pneumatic gauges have unstable measurement values and workpiece measurement wear.This article analyzes the measuring principles of the pneumatic gauges,performs numerical calculation and experimental measurement of its internal flow field,and finds that the existing probes of a connecting rod do not form an effective support.Air film and disordered airflow in the exhaust tank result in poor measurement stability;local high pressure zones are generated at the edge of the exhaust tank,leading to the increased air resistance coefficient,which affects the measurement accuracy.The dual E-type exhaust groove-structured probe with better measurement stability and reliability is proposed.By analyzing the internal flow characteristics of the dual E-type probe,its pressure and flow field distribution is more uniform.The air flow fluctuation converges to a stable value,and the measurement fluctuation amplitude is 1/5 of the existing probe,which effectively improves the measurement accuracy and stability.

关 键 词：气动量仪 稳定性 可靠性 排气槽 气阻系数 

分 类 号：O353.1[理学—流体力学]