简介：文章对柴油机的故障表象与诊断技术进行了综合分析，结合理论与实践列出了在柴油机故障诊断中的异常声响发生的部位、异响表象特征和故障基本原因，并以实例阐述了柴油机声响异常辨识在故障诊断中的应用，介绍了该故障诊断技术的发展应用前景。

简介：Inthepresentwork,computationalsimulationswasmadeusingANSYSCFXtopredicttheimprovementsinfilmcoolingperformancewithdualtrench.Dual-trenchconfigurationconsistsoftwotrenchestogether,onewidertrenchandtheotherisnarrowtrenchthatextrudedfromthewiderone.Severalblowingratiosintherange(0.5:5)wereinvestigated.Thepitch-to-diameterratioof2.775isused.Byusingthedualtrenchconfiguration,thecoolantjetimpactedthetrenchwalltwotimesallowingincreasingthespreadingofcoolantlaterallyinthetrench,reducingjetvelocityandjetcompletelycoveredonthesurface.Theresultsindicatethatthisconfigurationincreasedadiabaticeffectivenessasblowingratioincreased.Thespatiallyaveragedadiabaticeffectivenessreached57.6%foratM=2.Noobservedfilmblow-offatallblowingratios.Theadiabaticfilmeffectivenessofdualtrenchcaseoutperformedthenarrowtrenchcase,laidbackfan-shapedhole,fan-shapedholeandcylinderholeatdifferentblowingratios.

简介：文章阐明了PBL教学法在“船舶强度与结构设计”课程教学中的应用，介绍了其具体实施步骤。实施效果显示，该方法取得了良好的教学效果，具有一定的参考意义。