磨料浆体射流技术及其机理研究

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1、上海大学博士学位论文磨料浆体射流技术及其机理研究姓名：刘小健申请学位级别：博士专业：机械制造及其自动化指导教师：俞涛20060301上海大学博士学位论文用纸后者300GJ／m3以上，而切割能力稍弱于后者。另外，基于对试验进行理论预测和质量监控的需要，还对磨料浆体射流进行了切割深度建模研究。关键词：磨料浆体，流变特性，本构方程，交错网格，流场特性，数值模拟切割性能，切割深度模型上海大学博士学位论文用纸AbstractWiththerapiddevelopmentofindustcialprocess，moreandmorehighpe

2、rformancemeterialsaredeveloped，andmanyofthemhavespecialstructures．Iftheyarecutviasomeconventionalmethods，it’sdifficulttogethighquality．Ⅶmenthemeterialsarecutwithsketchshapedspecially,it’sverydifficulttoobtainthedesignrequirement．Sincetheabrasivejetcuttinghasthefeatures

3、ofcoldconditions，point-cut，commonality,high-quatilyandpollution—free，itoccupiesmoreandmoreimportantpositioninthecuttingfield．Buttherearesomeshortagesintheexistingabrasivejettechnologyortherearesomeimperfectinfluencingthewideusingofitinourcountry．Suchashigh—pressure(>20

4、0Mpa)isusedinabrasivejetcuttingsytemandthismakeaapplicationbottleneckinourcountrybecauseofthenozzleabradabilityorthehermeticproblemwithhigh—pressurewhichinfluencethestabilityandthereliabilityofthesystem．Sincethenozzlesizeisbiggerinthedia—injectedabrasivewaterjetcutting

5、system，thecuttingwidthisbigger,thecuttingfaceisrougher,theabrasivegrainiseasyertodepositorpluginthepipe，andthecontinousfeederprocesscan’tberealized．11lispaperispresentedandstudiedwithabovetechnologybackground．theresearchmainlyreducesthesystempressureintheprocesstechnol

6、ogy，realizestherecycleduseoftheabrasivesuspensionandthehigh—pressuretransfermediumseparately,newprocessandmethodarepresentedwhichimprovetheprocesstructure，reducethemachiningcost．Therheologicalcharacters，theflowfieldcharactersareexploredandgrasped．thenumericalsimulation

7、oftheflowfieldinnozzleismade，theabrasivesuspensionjetcuttingperformanceisstudied．Inthispaper,thestructureofthehigh—pressuretankwhichisthekeydeviceofthesystemisdesigned，inwhichtheabrasivesuspensionandthehigh—pressuretransfermediumiscompleteisolated．Thetransfermechanismo

8、fthehigh—pressuretankoverseaischanged．Basedonthisfoundationalstudy,thetotalstructureandtheprocessflowaredesigned，ther