This article studies the influence of polymers on drag reduction and heat transfer enhancement of a nanofluid past a uniformly heated permeable vertically stretching surface. Our prime focus is on analyzing the possib...This article studies the influence of polymers on drag reduction and heat transfer enhancement of a nanofluid past a uniformly heated permeable vertically stretching surface. Our prime focus is on analyzing the possible effects of polymer inclusion in the nanofluid on drag coefficient, Nusselt number and Sherwood number. Dispersion model is considered to study the behavior of fluid flow and heat transfer in the presence of nanoparticles. Molecular approach is opted to explore polymer addition in the base fluid. An extra stress arises in the momentum equation as an outcome of polymer stretching. The governing boundary layer equations are solved numerically. Dependence of physical quantities of engineering interest on different flow parameters is studied. Reduction in drag coefficient, Nusselt number and Sherwood number is noticed because of polymer additives.展开更多
The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal ten...The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal tensile testing machine and dynamic mechanical analyzer(DMA).The mechanisms for damping capacity of referred alloys were discussed by Granato-Lücke theory.The results show that Y additions remarkably reduce grain size(the average grain size is 21.6,13.0,8.6 and 4.0μm,respectively),and the tensile properties are enhanced with grain refining(the yield tensile strength increases to 292 MPa from 210 MPa and ultimate tensile strength increases to 330 MPa from 315 MPa).For the ZK60-xY(x=0,1.5%,4.0%)alloys,the damping capacity decreases with the increase of Y content.However,for the ZK60-xY(x=2.5%)alloy,the damping capacity improves abnormally,which is possibly related to the formation of Mg3Y2Zn3(W)FCC phase in this alloy.展开更多
基金Project(IFP-A-2022-2-5-24) supported by Institutional Fund Projects,University of Hafr Al Batin,Saudi Arabia。
文摘This article studies the influence of polymers on drag reduction and heat transfer enhancement of a nanofluid past a uniformly heated permeable vertically stretching surface. Our prime focus is on analyzing the possible effects of polymer inclusion in the nanofluid on drag coefficient, Nusselt number and Sherwood number. Dispersion model is considered to study the behavior of fluid flow and heat transfer in the presence of nanoparticles. Molecular approach is opted to explore polymer addition in the base fluid. An extra stress arises in the momentum equation as an outcome of polymer stretching. The governing boundary layer equations are solved numerically. Dependence of physical quantities of engineering interest on different flow parameters is studied. Reduction in drag coefficient, Nusselt number and Sherwood number is noticed because of polymer additives.
基金Project(10876045)supported by the National Natural Science Foundation Commission of China and China Academy of Engineering PhysicsProject(50725413)supported by the National Natural Science Foundation of China+1 种基金Project(2007CB613704)supported by the National Basic Research Program of ChinaProject(CSTS2008AB4114)supported by Chongqing Science and Technology Commission(CQ CSTC)
文摘The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal tensile testing machine and dynamic mechanical analyzer(DMA).The mechanisms for damping capacity of referred alloys were discussed by Granato-Lücke theory.The results show that Y additions remarkably reduce grain size(the average grain size is 21.6,13.0,8.6 and 4.0μm,respectively),and the tensile properties are enhanced with grain refining(the yield tensile strength increases to 292 MPa from 210 MPa and ultimate tensile strength increases to 330 MPa from 315 MPa).For the ZK60-xY(x=0,1.5%,4.0%)alloys,the damping capacity decreases with the increase of Y content.However,for the ZK60-xY(x=2.5%)alloy,the damping capacity improves abnormally,which is possibly related to the formation of Mg3Y2Zn3(W)FCC phase in this alloy.
