Analysis of Conjugate Natural Convection Inside Heated Enclosure

Abstract

Inside a differentially heated cavity, a numerical study of conjugate natural convection is carried out. In this work, two separate situations are investigated: an enclosure with a wavy partition filled with heat generating fluid and an enclosure with a solid partition splitting the cavity into two different fluid zones, namely air and water. mTwo-dimensional continuity, mentum, and energy equations regulate thermal and flow properties inside the cavity. Numerical analysis for the wavy partitioned enclosure is performed over varying external Ra (103 ≤ Raae ≤ 108), various position of the wavy partition wall (Xp = .25L, 0. 50L and 0.75L), different frequencies of the wavy partition wall (f = 6, 9 and 12), and three varying thermal conductivity ratios. Similarly, numerical analysis over a varying range of Rayleigh number (103 ≤ Raa ≤ 106), various thickness of solid partition wall (.05L ≤ ε ≤ 0.2L), various location (.25L ≤ c ≤ 0.75L), and various thermal conductivity of the wall. The influences of the above governing parameters on the streamline and the isotherm plots are examined. Furthermore, the effect of partition wall thickness, location, and thermal conductivity on the Nu of hot and cold walls is estimated in the current study. The results suggest that increasing the thermal conductivity of the wall material enhances thermal exchange performance, whereas changing the position of the wavy partition wall has less of an impact. Heat transmission, however, reduces when the frequency of waviness increases. In the second scenario, the results show that increasing the wall material's thermal conductivity enhances heat transmission performance. Heat transmission is reduced when the thickness and distance of the partition wall from the cold end are increased. Similarly, a comparative analysis of the thermal exchange performance between the solid and wavy partitioned enclosure with and without the heat generating fluid is also analyzed in this study. Thermal exchange characteristics improved by nearly 8% and 15% for wavy partitioned enclosure at high Rayleigh number corresponding to enclosure filled without and with heat generating fluid respectively.