Showing papers by "Suhas V. Patankar published in 1992"

Numerical prediction of vortex shedding behind a square cylinder

Abstract: It is common knowledge that flow around bluff bodies exhibits oscillatory behaviour. The aim of the present study is to compute the steady two-dimensional flow around a square cylinder at different Reynolds numbers and to determine the onset of unsteadiness through a linear stability analysis of the steady flow. Stability of the steady flow to small two-dimensional perturbations is analysed by computing the evolution of these perturbations. An analysis of various time-stepping techniques is carried out to select the most appropriate technique for predicting the growth of the perturbations and hence the stability of the flow. The critical Reynolds number is determined from the growth rate of the perturbations. Computations are then made for periodic unsteady flow at a Reynolds number above the critical value. The predicted Strouhal number agrees well with experimental data. Heat transfer from the cylinder is also studied for the unsteady laminar flow.

Laminar, fully developed mixed convection in a vertical eccentric annulus

Abstract: This paper presents a numerical study of laminar, fully developed mixed convection in vertical eccentric annular duets. The equations governing the velocity and temperature are solved on a body-conforming grid by using a finite-volume technique. The effects of radius ratio, eccentricity, and Rayleigh number on the friction factor and the Nusselt number are discussed. The buoyancy forces significantly increase both friction and heat transfer. The effect of buoyancy is stronger for configuration with larger eccentricities.

Natural Convection in a Partitioned Cubic Enclosure

Abstract: Numerical solutions are obtained for fluid flow and heat transfer in a cubic enclosure with a vertical adiabatic partition. The two zones of the enclosure are connected by a single rectangular opening. The partition is oriented parallel to the isothermal sidewalls, one of which is heated and the other cooled while the remaining walls are adiabatic. Results have been presented for air for the Rayleigh numbers in the range 10{sup 4}-10{sup 7}. The width of the opening is held fixed while the height, relative to the enclosure height, is varied from 0.25 to 0.75. The effects of various parameters on the flow structure and heat transfer are investigated. The results of the three-dimensional simulation have also been compared with those for the corresponding two-dimensional configurations.