13499

1172 دكتري

دكتري

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

۱۳۹۶

هجده، ۲۱۹ص.: مصور، جدول، نمودار

محسن دوازده امامي

احمد رضا پيشه‌ور، حميدرضا سليمي جزي

محمود اشرفي زاده، احمد سوهانكار، محمد پسنديده‌فرد، مهرزاد شمس

1397/02/11

كتابنامه

مكانيك

مهندسي مكانيك

ID1172 دكتري

1008 Application of Compressible Volume Of Fluid VOF model in Simulating The production process of Hollow particles and Impact of a Hollow Droplet on a Surface Hadi Safaei h safaei@me iut ac ir Date of Submission 2017 11 23 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree Ph D Language FarsiSupervisor Mohsen DavazdahEmami mohsen@cc iut ac ir1st Advisor Ahmad Reza Pishevar apishe@cc iut ac ir2nd Advisor Hamid Reza Salimi Jazi hrjazi@cc iut ac irDepartment Graduate Coordinator Reza TikaniAbstractAt the beginning of this study the production process of hollow particles from the agglomerated particles isaddressed analytically and numerically The important parameters affecting this process in particular theinitial porosity level of particles are investigated In the analytical model the possibility of a solid coreexisting in agglomerated particles is examined In this model a range of particle diameters 50 m Dp0 160 m are considered The numerical model employs the VOF technique for two phase compressibleflows Simulation results of the analytical model indicate that the solid core diameter is independent of theinitial porosity whereas the thickness of the particle shell strongly depends on the initial porosity In the next step impact of a hollow droplet on a surface is simulated An open source finite volume basedCFD code was used to perform the simulations where appropriate sub programs were added to handle thestudied cases Results showed that at high impact velocities U 0 100 m s the droplet splashedexplosively Compressibility effects result in a more porous splat compared to the correspondingincompressible model Moreover the compressible model predicted a higher spread factor than theincompressible model due to planetary structure of the splat Key Words Compressible flow VOF model Thermal spray coating Hollow sphere particle OpenFOAM Solidification 1 IntroductionDroplet impact on a surface its spreading and solidification are being used in differentengineering applications including thermal spray coating shape depositionmanufacturing liquid metal jetting digital microfabrication etc In the plasma coatingtechnique particles of the feeding powder are heated as they pass through plasma melted partially or fully propelled and impacted on a substrate with a high velocity resulting ina protective layer on the substrate In thermal barrier coating TBC the thermal conductivity of particles is low in thefeeding powder Therefore during passing through the plasma most of them are not Department of Mechanical Engineering Isfahan University of Technology Isfahan Iran Department of Materials Engineering Isfahan University of Technology Isfahan Iran

محسن دوازده امامي

احمد رضا پيشه‌ور، حميدرضا سليمي جزي

محمود اشرفي زاده، احمد سوهانكار، محمد پسنديده‌فرد، مهرزاد شمس