多孔介质涂层管外液膜流动及传热的数值模拟研究OA

This study investigates the falling film characteristics outside porous-coated tubes from both flow and heat transfer perspectives by combining the Volume of Fluid(VOF)method with a porous media model.The research covers liquid film spreading behavior,flow patterns,film velocity,film thickness,and heat transfer coefficients for both conventional and porous-coated tubes,and examines the influence of porosity-a key parameter-on the overall heat transfer process.Results show that the developed model accurately reproduces the liquid film spreading process,as well as the distributions of film thickness and heat transfer coefficient,on horizontal porous-coated tubes.Specifically,compared to conventional tubes,porous-coated tubes exhibit slower liquid film spreading rates,making them more prone to film accumulation,thereby reducing localized dryout caused by film rupture.Porous-coated tubes also tend to achieve lower film velocities and more uniform heat transfer than conventional tubes.For porous-coated tubes,lower porosity and thicker films lead to higher heat transfer coefficients,an effect that becomes particularly pronounced when porosity is below 0.4.