Analytical study of laminar free convection in oils

[摘要] An analysis is made to investigate the effects of viscosity variation in a typical heat-transfer (transformer) oil by solving the classical inclined or vertical flat plate free convection problem with variable viscosity. The solutions of the boundary layer equations appropriate to the variable viscosity situation were carried out for a number of specific cases of viscosity ratios (mp) at the plate conditions. From the findings, it is concluded that free convection heat transfer under variable viscosity conditions can be computed accurately by using constant-property results in conjunction with intermediate temperature relation Ti = To + Y (Tp - To). It is further observed that in the application of results of a constant-property analysis to a variable property situation, the properties of the fluid of the analysis should be taken equal to those of the variable property fluid at the temperature of the plate.

[发布机构] Rice University