Effect of triangular solid inserts on optimization of conjugate natural convection in complex cavity

摘要

The focus of presented numerical study is to investigate the effect of solid inserts of triangular form on conjugate natural convection. The solid inserts are placed at the inner corners of a square cavity and are of various dimensions. The cavity studied here is filled with air (Pr = 0.71) and bounded by an upper horizontal conducting thick wall. The superior horizontal boundary of the thick wall and the bottom wall of the cavity are kept at adiabatic conditions, while, the vertical walls of the cavity are isothermal, at a temperature T_c . There is a heated circular cylinder centered inside the cavity of temperature T_h (T_h > T_c) . The study covered a wide range of the Rayleigh number, Ra from 10~3 to 10~6, and two thermal conductivity ratios of the conducting upper wall, k_w = 0.1 and 5.0. The thermal conductivity ratios k_(in) of solid inserts was changed between 0.1 and 100. The differential governing equations were solved using the commercial code FLUENT. The results show that the overall heat transfer rate is strongly affected by Rayleigh numbers and thermal conductivity ratios.