Journal of Applied Mechanical Engineering

Modeling of the coupled conduction-convection ice formation on a horizontal finned tube under density inversion conditions

Global Summit and Expo on Fluid Dynamics & Aerodynamics

August 15-16, 2016 London, UK

Ghalib Y Kahwaji, Mohamed A Samaha and Hassan M S A Sarrach

Rochester Institute of Technology, Dubai Campus, UAE
University of Mosul, Iraq
State University of New Jersey, Piscataway, USA

Scientific Tracks Abstracts: J Appl Mech Eng

Abstract:

The freezing of water around finned and unfinned horizontal tubes inside an insulated tank is analyzed and numerically simulated. The coupled conduction-convection heat transfer with phase change moving interface is solved numerically using finite difference technique. Adaptive grid generation is performed by elliptic partial differential equations coupled with a proportional, iterative smoothing algorithm. The effect of density inversion with temperature on flow patterns is also considered. For validation, the present results are compared with experimental studies reported in the literature. The flow patterns are similar in both cases as there is one main vortex in the liquid region when there is no inversion in water density. The vortices of water existing before and after the inversion process are also similar. The inversion in density was found to disturb the flow patterns and the isothermal lines in the liquid region. The presence of fins complicates the local Nusselt Number distribution along the solid-liquid interface in comparison with the unfinned cylinder. The impact of natural convection on the rate of ice formation is limited to the initial starting time only. Its effect on unfinned tube is more obvious than that on the finned tube due to the increase of contact area, which speeds the cooling of the liquid region. It is observed that the mass of ice formed under the effect of natural convection is less than that formed for conduction controlled freezing by about 27%.

Biography :

Ghalib Y Kahwaji completed his PhD in Mechanical Engineering from Colorado State University. He is working as Professor and Chair in Department of Mechanical and Industrial Engineering at RIT-Dubai. He joined RIT-Dubai as a Professor of thermo-fluids, air conditioning and renewable energy systems. Prior to joining RIT, he spent five years in industry and engineering consulting as the Head of MEP Design Department and Engineering Manager at Al-Gurg Consultants, Dubai and TRANSCO, Abu Dhabi where his work involved large scale water transmission systems and energy systems for high rise and industrial buildings in the UAE. Prior to moving to the UAE, he served as the Associate Dean for research and graduate programs and Chairman of the Department of Mechanical Engineering at the College of Engineering, University of Mosul from 2003 till 2006 and was as a Faculty of Mechanical Engineering since 1987.

Email: gykcad@rit.edu