Numerical Studies on Natural Convection in a Trapezoidal Enclosure With Discrete Heating

Abstract

A steady state laminar natural convection flow in a trapezoidal enclosure with discretely heated bottom wall, adiabatic top wall, and constant temperature cold inclined walls is performed. The finite volume based commercial code “ANSYS-FLUENT” is used to investigate the influence of discrete heating on natural convection flows in a trapezoidal cavity. The numerical solution of the problem covers various Rayleigh numbers ranging from 10³ to 10⁶, non-dimensional heating length ranging from 0.2 to 0.8 and Prandtl number is 0.7. The performance of the present numerical approach is represented in the form of streamfunction, temperature profile and Nusselt number. Heat transfer increases with increase of Rayleigh numbers at the corners of the cavity for same heating length from center of the bottom wall. However, the heat transfer rate is less and almost constant for the Rayleigh numbers considered. It is found that the average Nusselt number monotonically increases with increase of Rayleigh number and length of heat source. The variation of local and average Nusselt numbers is more significant for larger length of heating than smaller one. The heat transfer correlations useful for practical design problems have been predicted.

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Notes on contributors

Krishne Gowda B. Mote Gowda

Krishne Gowda B. Mote Gowda obtained his bachelor’s degree in Mechanical Engineering from NIE-MYSURU and M. Tech., from SIT-TUMKUR, in Thermal Power Engineering He started his career at Alpha College of Engineering as Lecturer in Mechanical Engineering Department and served for four years. Presently working as Assistant Professor at Sri Krishna Institute of Technology, Bangalore. His area of interest is natural convection heat transfer study using computational fluid dynamics.

Madurai S. Rajagopal

Maduari S. Rajagopal obtained his bachelor’s degree Mechanical Engineering from UVCE, Bangalore in 1981. His Masters and Ph.D. were obtained from IIT, Madras in Thermal Sciences. He started his career at Kirloskar Electric Co. Ltd and served for 15 years in various departments such as Design, Development and Research. He was one of the main contributors in developing energy efficient Motors and the next generation Alternators. He joined NIIT Ltd. In 1999 to head their new Engineering Services division. Subsequently, he joined GE, John Welch Technology Research Centre and was heading the Advanced Design and Methods group. Later he made a conscious shift towards a career in Academics and worked at PESIT and BMSIT. Subsequently he worked at Geometric Ltd for two years in CAE as Project Manager before joining Oxford College of Engineering. Presently he is working as Professor and Head at Global Academy of Technology, Bengaluru. He has 14 publications in International journals and conferences. His areas of research include computational heat transfer and fluid dynamics applications in engineering, pulsating heat pipes and natural convection simulation studies.

Aswatha

Aswatha obtained his bachelor’s degree in Mechanical Engineering from Bangalore University, Bangalore in 1998. His Masters and Ph.D. were obtained from Visvevaraya Technological University, Belgaum. He is presently working as Associate Professor in the Department of Mechanical Engineering at Bangalore Institute of Technology, Bangalore. His areas of interest are fluid flow, natural convection heat and mass transfer in enclosures, thermal management in data centers and electronic systems, and computational fluid dynamics. He has about 10 international journal publications.

Kankanhalli N. Seethramu

Kanakanhalli N. Seetharamu is a chair professor in the thermal engineering at the PES university Bangalore. Earlier he worked at IIT Madras as a professor of Mechanical Engineering. He has also worked as professor at the University Sains Malaysia. His areas of interest are heat and mass transfer in porous media, natural convection in enclosures, thermal management in electronic systems, analysis of heat exchangers with finite element methods, and computational fluid dynamics. He has about 190 international journal publications. He is author of three books on the finite element analysis to heat and mass transfer published by John Wiley UK.