Research On Convective Heat Transfer Of Nanofluid Flowing Through Vertical Plate Under Magnetic Field

The global economy continues to evolve and the energy needed is gradually increasing,and fossil fuels provide a large part of our energy to be used in the form of heat.In many industrial equipment,the energy transport process is often accompanied by heat transfer,which requires more advanced heat transfer technology.Nano-fluid is a stable suspension of nano-sized particles dispersed in the traditional base fluid,which has a clear advantage in the field of enhanced heat transfer,making the heat exchange system more reliable,more economical and more miniaturized.Theoretical study on the convective heat transfer of the nanosphere boundary layer is also a reflection of the innovative application of nanotechnology in thermal engineering.In this paper,the method of dealing with partial differential equations is different from the traditional stream function method,which is a new similarity transformation method.In this method,several dimensionless variables describing the natural convection and forced convection of nanofluid under magnetic field are deduced by dimension analysis method.Compared with traditional flow function method,the traditional flow function is replaced by dimensionless velocity component.Intuitive,with physical meaning,while the system has a lower order effect.The bvp4 c method can be used to calculate the two-point boundary value differential equation problem.It is used to solve the transformed equations,calculate the convective heat transfer parameters,and analyze the influence of the solution parameters on convective heat transfer.The main contents of this paper are as follows:(1)First,for the conventional fluid natural convection and forced convection boundary layer equations,according to the dimensional analysis and Bu Jinhan theorem,respectively,to derive the natural convection and forced convection of several dimensionless variables.(2)For the nanofluids under magnetic field,a specific premise is put forward,and the mathematical model of forced convection and natural convection of nanofluids undermagnetic field is constructed respectively.(3)to improve the above-mentioned dimensionless variables,so that it applies to the role of magnetic field under the nano-fluid.The second-order partial derivative expression of the dimensionless quantity is calculated and the original partial differential equations are similarly deformed.(4)Based on the Hamilton-Crosser model and Brinkman formula model,the expressions of surface friction coefficient,local Nusselt number,plate heat transfer flux and heat transfer are deduced by using nano-fluid homogeneous model for engineering application reference,And derive the equations for the calculation of the program.(5)For the conventional fluid,the bvp4 c method is used to study the effect of the magnetic field on the velocity and temperature boundary layer.(6)using three different nanoparticles,respectively,and bvp4 c method to solve,calculate the wall velocity gradient and temperature gradient,the study of surface friction coefficient,Nusselt number and their relationship,compared with the literature to verify Its correctness.At the same time to study M,?,Pr on the speed of temperature.The effect of the boundary layer is that the nanoparticles with the highest heat transfer capacity are established in these three nanoparticles.