内燃机进气道

使含添加剂内燃机油飞溅到高温金属表面形成漆膜，以此模拟曲轴箱油在活塞工作时的成漆情况，并用在试验机油箱内挂铅片的方法模拟曲轴箱油在气液相氧化状态下对发动机零部件的腐蚀。通过测定金属板上的漆膜评级和胶重，考察油品的热氧化安定性。将250mL试油在规定条件下，在模拟试验机内运行6h后，考察形成漆膜和成胶情况。

Modern spark-ignited internal combustion engines have intake ports designed to introducehigh levels of so-called “tumble” charge motion. Correspondingly high shear rates can lead to highfluctuations and turbulence within the combustion chamber. A suitable test case to characterize theintake flow is a steady-state flow bench. Although routinely used in the engine development processto determine the global discharge coefficients, only a few detailed numerical and experimentalstudies use this test case to analyze the flow in the vicinity of the valve with high spatial andtemporal resolution. In this paper, we combined highly resolved two-dimensional, two-componentParticle Image Velocimetry (PIV) measurements and numerical simulations using a Detached-EddySimulation (DES) model to characterize engine-relevant flow features on a flow bench. The spatialresolution of numerical simulations on two different grids is assessed and compared to that of thePIV measurement. The results of simulations and experiment are then compared in terms of theirmean and fluctuation velocity fields and the jet orientation. A detailed study of the area around thevalve seats investigates the validity of wall functions in this region. Finally, we examine structuresinduced by vortex-shedding at the valve stem and if they are transported into the combustion chamber.

用DEHS发烟机生成示踪粒子。一对1百万像素CMOS相机作成像部件。工作频率16.6KHz。用LaVision的DaVis8.3如件来分析所记录的图像。对结果进行了本征正交分解POD分析。对S-型进气道扰动流场的不稳定性，进行了实验测量和分析。