具有叶尖小翼的涡轮叶栅间隙流动的实验研究

ExperimentalInvestigationonTipClearanceFlowofaTurbine

关键词:  涡轮叶栅  间隙泄漏流动  叶尖小翼  实验研究中图分类号:V235.1文献标识码:A文章编号:1001-4055(2015)12-1825-08DOI:10.13675/j.cnki.tjjs.2015.12.010

Key words:  Turbinecascade  Tipleakageflow  Tipwinglet  Experimentalinvestigation

摘要:

涡轮动叶叶顶间隙流动是引起动叶内部流动损失的重要因素之一，大约30%的流动损失是由间隙流动引起的。对高负荷涡轮叶栅在间隙高度1%叶高、0°冲角的条件下，加装不同宽度和安装位置的叶尖小翼进行了实验研究，结果表明，压力面小翼在一定程度上削弱了泄漏涡强度，0.3倍叶片当地厚度的压力面小翼效果最佳。吸力面小翼可使泄漏涡运动轨迹向相邻叶片的压力面侧偏移、泄漏涡强度减弱，间隙泄漏损失降低。随着吸力面叶尖小翼宽度的不断增加，叶尖小翼对泄漏流动的控制作用也不断增强，当宽度在1.2倍叶片当地厚度时，对泄漏流动控制效果最好，可使叶栅测量截面总损失与不加小翼的叶栅相比降低28%。组合小翼不如单纯的吸力面小翼效果好。

Abstract:

Tipleakageflowisoneofthemostinfluentialfeaturesoftheflowthroughturbinerotor，whichisresponsibleforasmuchas30%ofthetotalaerodynamiclosses.Adetailedexperimentalstudyhasbeencarriedouttoinvestigatetheeffectofbladetipwingletwithdifferentinstallationpositionsanddifferentwidthsontheper.formanceofaturbinecascade，under1%bladeheighttipclearances，0°angleofattack.Experimentalresultsshowthat，forthecaseswithpressure-sidewinglet，thestrengthoftipleakagevortexcanbereducedandtheop.timalwingletwidthis0.3timesofthelocalbladethickness.Forthecaseswithsuction-sidewinglet，thetipleak.agevortextrajectoryshiftstowardthepressuresurfaceoftheadjacentblade.Moreover，thestrengthoftipleak.agevortexandthetipleakagelossarereduced.Asthewingletwidthincreases，theeffectsofthesuction-sidewingletonleakageflowareenhanced.Theoptimalwingletwidthisabout1.2timesofthelocalbladethicknessandthetotalpressurelossofthecascadesmeasuringsectionisreducedbyabout28%whencomparedwiththebaselinetipblade.Theinfluenceofcombinedwingletcaseisnotaseffectiveassuction-sidewingletcase.