Numerical Analysis of Laminar Natural Convection Inside Enclosed Squared and Trapezoidal Cavities at Different Inclination Angles

Mohammad Sultan Mahmud; Md. Mahbubur Rahman; Md Nahid Zaman Liton

doi:10.38032/jea.2024.01.001

Authors

Mohammad Sultan Mahmud Department of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna-9203, Bangladesh
Md. Mahbubur Rahman Department of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna-9203, Bangladesh
Md Nahid Zaman Liton Department of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna-9203, Bangladesh

DOI:

https://doi.org/10.38032/jea.2024.01.001

Keywords:

Natural Convection, Inclination Angle, Nusselt Number, Rayleigh Number, Laminar Flow

Abstract

The effects of cavity shape by inclination angle on laminar natural convection inside trapezoidal and square-shaped cavities have been numerically investigated in this work. Several simulations had been conducted for various inclinations of the trapezoidal cavity at Rayleigh numbers (Ra) =10⁵ to 10⁶ in a laminar flow regime. The walls at the left and right sides of the cavities were heated isothermally, while the walls at the top and bottom sides were adiabatic. The problem was assumed to be 2-D and solved using the software package ANSYS Fluent 16.2. Cavity filled with air is examined in two distinct instances; varying boundary layers and the flow generated for the natural convection. This numerical study analyzed the flow characteristics, temperature distribution, and Nusselt number. The analysis reveals that as the Rayleigh number increases, the Nusselt number also increases, with a more pronounced effect at higher Rayleigh numbers. It has been observed that there is a substantial effect of cavity shapes on the Nusselt number. The presence of an angled wall inhibits convection resulting in stronger flow in the squared cavity compared to the trapezoidal cavity. From numerical results, it is also found that the temperature distribution at Ra = 10⁵ is wider than the temperature distribution at Ra= 10⁶.

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