蒸氣凝結(jié)的分子動(dòng)力學(xué)研究.pdf

1、重慶大學(xué)碩士學(xué)位論文蒸氣凝結(jié)的分子動(dòng)力學(xué)研究姓名：鄔小波申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：工程熱物理指導(dǎo)教師：劉朝201005英文摘要IIIABSTRACTIntheprocessesofcondensationboilingcrystallizationcatalysisotherengineeringproblemsthenucleationphenomenonplaysacriticalrole.Nucleationisacomplicat

2、edphysicalprocesswhichcontainsthemicrocosmicmacroscopicprocessthemicromechanismofnucleationisnottotallyunderstood.Thisthesisisfocusesonthenucleationphenomenonintheprocessofcondensation.Basedonthestatisticthermodynamicsth

3、eiesweadoptmoleculedynamicssimulation(MDS)LennardJones(LJ)potentialfunctiontoinvestigatethenucleationprocess.Firstlytheacteristicoffractionaldimensionnumberofcondensationnucleusunderthecoolingvelocityof0.0002wasanalyzedt

4、heeticallybasedonthefractaltheyitwasfoundthatthefractionaldimensionnumberofcondensationnucleuswas1.593.Thenucleationprocesswasanalyzedbytheclustertheytheresultsshowthattheprocessofvapcondensationisdividedintolatentheatre

5、leasingsensibleheatreleasingprocesses.Amodeloffcefunctionwasbuiltupsimulationofnonhomogeneousnucleationprocesswascarriedout.Bycomparingthehomogeneousnucleationprocesswiththenonhomogeneousnucleationprocessunderthesamecool

6、ingvelocityof0.0002itwasfoundthatthenucleusofcondensationofhomogeneousnucleationisrombutthenucleusofcondensationofnonhomogeneousnucleationisfixeditjustisthepositionallocated.Secondlythehomogenousnucleationofargonvapwasst

7、udiedbymoleculardynamicsimulationthenucleationratewascalculatedbythreemethodsCNTtheyMFPTClusterthey.ItwasindicatedthatunderthesamesimulationconditionthenucleationratescalculatedbyMFPTClustertheybelongedtothesamederofmagn

8、itudewhichwerethreedersofmagnitudebiggerthanthatofCNTthey.ThedifferenceamongthemcanbeexplainedbytheequilibriumthermodynamicsassumptionwhenthenucleationratewascalculatedbyCNTthey.HoweverfthreemethodsthecriticalClusternumb

9、erofhomogenousnucleationwasverycloselyto20.AdditionallybytheClustertheyanalysisitturnedoutthatthenucleationratewasbiggerasthecoolingrateincreasingwhichwasclosetopracticalhomogeneousnucleation.Thirdlythebubblenucleationin