NUMERICAL SIMULATION OF UNSTEADY HEAT TRANSFER IN A HALF-MOON SHAPE ENCLOSURE WITH VARIABLE THERMAL BOUNDARY CONDITION FOR DIFFERENT NANOFLUIDS

摘要

A half-moon shape enclosure which has a very wide range of practical applications in heat transfer is introduced for the first time in this article. The heat transfer is analyzed introducing different commercially available nanofluids such as water-Al_2O_3, water-Cu, water- TiO_2 in this half-moon enclosure. A variable thermal boundary condition is assigned to the model, and the finite-element method is used for the numerical solution of the problem. The effect of solid volume fraction φ, along with a wide range of Rayleigh numbers (Ra=10~5-10~7), are evaluated in various dimensionless times τ. The performance of the shape is described by using streamfunctions, isotherms, charts, and related graphs. It is found that heat transfer in the cavity can be enhanced up to 30% by to the presence of nanoparticles.