Study On Flow Heat And Mass Transfer Of Two Kinds Of Complex Fluids

Semi-volatile organic compounds(SVOCs)widely exist in indoor building materials,which seriously affect human health.It is of great significance to study their release laws;polymer films affect the performance of products due to their rheological behavior during processing.Heat transfer behavior is of great value.In this paper,the mass transfer of SVOCs in porous building materials and the flow heat transfer of Welan gum film were discussed respectively.The contents of the study are as follows:1)Based on the fractional Fick’s law,the diffusion model of SVOCs in polyvinyl chloride(PVC)floor and wallpaper was established,and the fractional convective mass transfer equation at the material surface was constructed.At the same time,the mass balance equation of SVOCs in the environmental chamber is corrected.The release process of diethylhexyl phthalate(DEHP)was simulated based on the non-uniform initial emission concentration,and the effects of various key parameters on the release of DEHP were revealed.In addition,the adsorption capacity and adsorption rate of2,2,4-trimethyl-1,3-pentanediol diisobutyrate(TXIB)on the inner wall of the environmental chamber were numerically simulated for the first time through environmental chamber experiments.2)Based on the shear-thinning and elastic properties of Welan gum solution,a flow and heat transfer model of Maxwell-power-law nanofluidic films on permeable stretch plates was established,and the velocity-slip and convective heat transfer boundary conditions were modified.The governing equations are transformed into ordinary differential equations by appropriate similarity transformation,and the approximate analytical solutions of the differential equations are obtained by combining the two-parameter deformation expansion method(DPTEM).The effects of magnetic field and nanoparticles on flow were analyzed,and the effects of various physical parameters on film thickness,velocity field and temperature field were revealed.The fractional SVOC mass transfer model constructed in this paper lays the foundation for the foundation for the study of mass transfer with both diffusion and adsorption characteristics.The constructed Maxwell-power-law fluid flow heat transfer model provides a new research idea for the study of flow heat transfer of non-Newtonian fluids with shear thinning and elastic properties at the same time.