Abo Bibliothek: Guest

ISBN: 978-1-56700-537-0

ISBN Online: 978-1-56700-538-7

ISSN Online: 2377-424X

International Heat Transfer Conference 17
August, 14-18, 2023, Cape Town, South Africa

NUMERICAL SIMULATION OF HEAT TRANSFER IN TERMITE MOUNDS

Get access (open in a dialog) DOI: 10.1615/IHTC17.210-380
10 pages

Abstrakt

Termites (Isoptera) are known to construct multi-purpose mounds to protect their colonies from hostile environmental conditions and predators as well as to provide them with a stable, ventilated, and temperature-regulated nest. The ideal temperature for termites is ranged between 24°C and 35°C. (e.g., about 30°C in nests of Macrotermes michaelseni in Namibia, Africa, and Coptotermes acinaciformis in Darwin, Australia). To find the temperature distribution in the mound of M. michaelseni, a 2-D steady-state equation of heat transfer was considered. The heat transfer by weak air convection through conduits in the mound was modelled by considering a high-conductivity path comprising a central chimney and two lateral conduits. This simplification is done based on the geometrical features of typical M. michaelseni taken from literature. By using the commercial software package COMSOL Multiphysics, the results of this model are validated by published results and provide some insights into the model's limitations (e.g., inaccurate prediction of about 95°C of the nest temperature). These results suggest that there are also other mechanisms required to produce a more realistic nest temperature. Evaporative cooling is one such mechanism that needs to be considered. To understand the significance of various parameters, a local sensitivity (single factor) analysis is conducted to evaluate the effect of these parameters in climatizing M. michaelseni mound: metabolic heat produced by termites, solar irradiance, and ambient air velocity. This analysis confirms that metabolic heat as a single factor has a stronger effect on the estimated nest temperature with a sensitivity index of 0.71 compared with 0.28 for solar irradiance and 0.08 for wind velocity. This raises an interesting heat transfer question of ventilation and thermoregulation in C. acinaciformis mounds that is yet to be answered as these mounds do not have clear conduits as found in African termites (M. michaelseni).