含空穴炸药硝基甲烷冲击转爆轰过程的数值模拟

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中图分类号：0381 国标学科代码：13035 文献标志码：A

Numerical simulation for shock to detonation process of explosive nitromethane containing cavities

XIAO Min1，WANG Cheng²，YANG Tonghui³ （1. College ofScience， China University of Petroleum，Beijing102249，China; 2.State KeyLboratoryofExplosioncienceandafetyrotectioneiingInstituteofchnologyBeijingChina; 3.School ofAerospace Engineering， Tsinghua University，Beijing l0oo84， China）

Abstract：Inordertostudytheinitiationprocessofliquidexplosivenitromethanecontainingcavitiesunder shock wave loading，anEulerianmulti-materialcomputationalapproachbasedonthelevelsetmethodwasdeveloped.ThereactiveEuler equation wereadoptedasthegoverming equations，the levelsetmethod wasutilizedto track themulti-medium interface between the chemicalreactionmixture and thecavity.To improve the robustnessofcalculation method，the modified ghost fluidmethod wasapplied incomputationalcelsnearthe interface.Basedonthe modified ghostfluid method，amulti-medium problem was transformed intoasingle media problem.For these twofluid phasesonboth sidesofthe interface，the highorder weightedessentialnon-oscilatoryfinitedifferencemethodwasimplemented tocalculatethenumerical fluxesoncel boundary，making the simulationresultsreliable. However，the Jones-Wilkins-Leeequationof state difers greatly from the ideal gasequationofstate.Inadition，the massfractionofdetonation productdirectlyaffects the transformationprocess betweentheconserved variablesand the primitive variables inreaction zone，making itdificultto provideanexplicit expresion for the equationof state of explosive mixture.Inorder to solve the above problems，a ghost fluidstate prediction method based on the Harten-Lax-van Ler-contact （HLLC）approximate Riemann solver was developed.Bydealing with a complexmulti-medium Riemann problemconsidering chemicalreaction，thevariable statesof ghost fluidonboth sides of the interface can be obtained.The multi-medium calculation method was used tosimulate the interaction problems between liquid nitromethaneandthecavityundertheloadingcondition withdiferentimpactstrengths.Thenumericalresultsillustratetatthe method proposed inthepapercancapture theentirefluiddynamics processofcavitycompresson，cavitycolapse，cavity closure and cavity disappearance.

Keywords： liquid nitromethane; cavity colapse; multi-medium interface; level set method; ghost fluid

炸药在浇铸、压装过程中很难避免在内部形成空穴。（剩余18020字）