Isothermal Rectangular Roughness Elements in a Rectangular Cavity Heated at Bottom


The purpose of the present research was to explore the role of rectangular roughness elements during natural convection in a two-dimensional rectangular cavity. The computational algorithm was developed based on the single relaxation time Bhatnagr-Gross and Krook (BGK) model of lattice Boltzmann method (LBM). Rectangular roughness elements were located on the horizontal walls. The computational algorithm was validated against benchmark studies using different numerical techniques, and a good agreement was found to exist. The range of the Rayleigh (Ra) number was explored from 103 to 106 for a Newtonian fluid of Prandtl number equal to 1.0. The dimensionless amplitude (h/H) of roughness elements was fixed to 0.1, while the spacing between these elements was equal to twice their height. The maximum reduction in the average heat transfer was calculated to be 27 percent at Ra number 1x106.

Meeting Name

2016 24th International Conference on Nuclear Engineering, ICONE24 (2016: Jun. 26-30, Charlotte, NC)


Nuclear Engineering and Radiation Science

Keywords and Phrases

Cavity resonators; Computational fluid dynamics; Heat convection; Kinetic theory; Newtonian liquids; Nuclear engineering; Prandtl number; Surface roughness; Average heat transfers; Computational algorithm; Dimensionless amplitude; Lattice Boltzmann method; Lattice boltzmann methods (LBM); Rectangular cavity; Single relaxation time; Two-dimensional rectangular; Heat transfer; Convection; Roughness

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2016 American Society of Mechanical Engineers (ASME), All rights reserved.

Publication Date

01 Jun 2016