基于NURBS曲面的汽輪機葉片重構(gòu)及插補算法的應(yīng)用研究.pdf

1、華北電力大學(xué)（保定）博士學(xué)位論文基于NURBS曲面的汽輪機葉片重構(gòu)及插補算法的應(yīng)用研究姓名：樂英申請學(xué)位級別：博士專業(yè)：動力工程及工程熱物理；熱能工程指導(dǎo)教師：王璋奇；韓慶瑤201103華北電力大學(xué)博士學(xué)位論文IIAbstractSteamturbinebladeisthekeycomponentitsdesignmanufacturelevelisoneofmajindicesofsteamturbinetechnology.Inde

2、rtoraisesteamturbinesstageefficiencythebladeprofileshapeismecomplextheprocessingtechnicsupdatecontinuouslytheprocessingrequestismestrict.Itsmachiningaccuracyqualityinfluencetheunitsoperatingefficiencysecurityreliabilityt

3、herefehowtoincreasethemachiningaccuracyefficiencyofthebladeisanimptanttopicwhichthedomesticfeignscholarsstudyallthetime.Thesteamturbinebladeprofileshapeiscomplexitcontainstheconicsectionthefreecurve.Onthebasisofthoughstu

4、dyofsurfacereconstructionmethodthe33degree23degreeNURBSsurfacematrixexpressionsareobtained.Themathematicsmodelofthebladeisbuiltbasedonthe33degree23degreeNURBSsurface.Thesteamturbinebladesurfacedigitizationexpressionisrea

5、lized.Thefittingerrisanalysedcomputed.ToimprovethemachiningaccuracyefficiencyofthesteamturbinebladetheNURBScurvedirectinterpolationalgithmbasedontheredundanterrisanalysedcomparedwiththeconstantfeedrateinterpolationalgith

6、mequalchderrinterpolationalgithmstheadaptivefeedspeedinterpolationalgithmwithconfinedchderrsfromseveralaspectsincludingthemachiningaccuracythefeedratetheinterpolationtimeaswellasaccelerationsoon.Theseinterpolationalgithm

7、sareusedontheblade.TheresultsshowthatNURBScurvedirectinterpolationalgithmbasedontheredundanterrusedonthesteamturbinebladereducetheerrredundantwhenthebladecurvatureradiusislarge.Thechderrtoleranceisconfinedtoallowedlimit.

8、Theexperimentalresultsareshowedthatthemachiningefficiencyofbladeisnotonlyimprovedbutalsothecontouraccuracyisguaranteed.Accdingtotheprofilesurfacefeatureofthesteamturbinebladetherowspaceiscalculatedwithconstantparameterme

9、thod.Thecuttingsteplengthiscalculatedaccdingtotheinterpolationalgithmbasedonredundanterr.Thecuttingtoolposturethetooldimensionarereasonabletobechosen.Theprocessingparametersareoptimized.Itisadvantageousinenhancestheblade

10、machiningaccuracyefficiency.Thethreedimensionalentitymodelisestablished.ThebladenumericalcontrolmachiningprocessissimulatedusingtheCimatronsoftware.ThebladeprocessNCcodeisgeneratedthebladeprofileismachinedusingthenumeric