Numerical Investigation of Natural Heat Convection in a Triangular Enclosure with a Varying-Diameter Cylindrical Heat Source

Abstract:

This work offerings a numerical study of natural convection heat transfer within a triangular enclosure having a centrally positioned cylindrical heating source. The effect of the heat source size is investigated by varying its non-dimensional diameter from 0.1 to 0.5. The eating source cylinder and enclosure are maintained at constant temperatures. The buoyancy-driven flow field is analyzed using streamline distributions, non-dimensional velocity magnitudes, and isotherm contours. Results reveal that the size of the internal heating source significantly affects the thermal performance of the combined structure. For small values of , the flow remains weak and localized, with limited convective motion. As increases to moderate values ≈0.3, recirculation regions intensify, velocity fields expand, and thermal plumes rise symmetrically, which indicates enhanced convective transport. However, additional increasing of values leads to flow constriction, reduced circulation strength, and causes less effective heat transfer. It is found that the average Nusselt number decreases with increasing due to diminished temperature gradients and restricted fluid motion despite the larger surface area provided by bigger cylinders. The results are applicable for the design of passive electronic cooling systems, solar thermal collectors, and other natural heat convection-based enclosures.

• Periodical: Advanced Engineering Forum (Volume 58)
• Pages: 39-50
• DOI: https://doi.org/10.4028/p-j9VuPu
• Online since: February 2026
• Authors: Safaa H. Faisal*, Tahseen A. Jabbar, Ruslan Sabah Abdulrahman, Farah Abdalsalam Ibrahim
• Keywords: Buoyancy-Driven Flow, Natural Convection, Nusselt Number, Passive Cooling Systems, Triangular Enclosure

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