ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Lattice Boltzmann Simulation of Oscillatory behaviour of Horizontal Vents at High Rayleigh number
The buoyancy induced air flow through horizontal vent is important for natural ventilation, in case of fire and for nuclear reactor containment applications. The heated room is connected to the environment through a horizontal vent. In this scenario, the lighter fluid is inside the heated room and heavier fluid is located above the horizontal vent. This constitutes a gravitationally unstable system and flow through the opening is unstable, bidirectional and oscillatory in nature. In the present work a 2D square enclosure has been considered where a linear heater of 1/5th of compartment length is placed in the bottom center. An opening is located of similar size in the top center location. Numerical simulations have been performed for high Rayleigh number ranging from 107 to 1010 using lattice Boltzmann method. The code has been validated for differential heated cavity problem for similar Rayleigh numbers. In the investigation buoyancy term is represented by the Boussinesq approximation. The effect of Rayleigh number on flow and heat transfer through opening has been investigated. Transient results show oscillatory flow behaviour through the opening. The present paper presents results of detailed numerical model, its validation and its application for analyzing oscillatory flow behaviour of horizontal vent.