Showing papers by "Suhas V. Patankar published in 1987"
TL;DR: Fluid flow and heat transfer in two-dimensional finned passages were analyzed for constant property laminar flow as discussed by the authors, where the passage is formed by two parallel plates to which fins are attached in a staggered fashion.
Abstract: Fluid flow and heat transfer in two-dimensional finned passages were analyzed for constant property laminar flow. The passage is formed by two parallel plates to which fins are attached in a staggered fashion. Both the plates are maintained at a constant temperature. Streamwise periodic variation of the cross-sectional area causes the flow and temperature fields to repeat periodically after a certain developing length. Computations were performed for different values of the Reynolds number, the Prandtl number, geometric parameters, and the fin-conductance parameter. The fins were found to cause the flow to deflect significantly and impinge upon the opposite wall so as to increase the heat transfer significantly. However, the associated increase in pressure drop was an order of magnitude higher than the increase in heat transfer. Streamline patterns and local heat transfer results are presented in addition to the overall results.
175 citations
TL;DR: In this article, an analysis is made of the laminar natural convection in a vertical shrouded fin array, in which the flow is induced from the surroundings by the chimney effect.
Abstract: An analysis is made of the laminar natural convection in a vertical shrouded fin array, in which the flow is induced from the surroundings by the chimney effect. This involves the calculation of developing flow in a duct. The results are obtained numerically for representative values of the parameters describing the system geometry and ducts of different lengths. The axial development of various flow quantities, such as the Nusselt number and the bulk temperature, has been presented. In addition, the overall flow and heat transfer characteristics have been discussed.
47 citations
46 citations
01 Aug 1987
TL;DR: In this paper, a modification to the production term in the turbulent kinetic energy equation is proposed which is based on a simple stability criterion and correlated to the free-stream turbulence level, but is shown to improve both the qualitative and quantitative characteristics of the transition predictions.
Abstract: The prediction characteristics and capabilities of two popular two-equation low-Reynolds-number turbulence models (Jones, Launder 1972; Lam, Bremhorst 1981) have been evaluated with respect to the prediction of transition of a flat plate under the influence of free-stream turbulence. The sensitivity of the predictions to free-stream turbulence intensity, initial starting location of the calculation, and the assumed initial starting profiles for k and epsilon has been determined and presented. Although both models predict the correct qualitative characteristics of transition, they also exhibit significant quantitative deficiencies with regard to both the predicted location and the length of transition. A modification to the production term in the turbulent kinetic energy equation is proposed which is based on a simple stability criterion and correlated to the free-stream turbulence level. The modification becomes inactive in the fully turbulent regime, but is shown to improve both the qualitative and quantitative characteristics of the transition predictions.
14 citations
TL;DR: In this article, a finite-element method for predicting flow through ducts of arbitrary and varying cross sections is presented, where the governing differential equations are discretized using a control-volume approach.
Abstract: A finite-element method for predicting flow through ducts of arbitrary and varying cross sections is presented. The governing differential equations are discretized using a control-volume approach. For this purpose, specially constructed three-dimensional control volumes are employed. The method is of the marching type and is based an a fully implicit formulation. Here, in part I of the paper, only the basic methodology is described; in the accompanying pan II, results of application of the method to some test problems are presented.
10 citations
01 Oct 1987
TL;DR: In this paper, a modified form of the Lam-Bremhorst low-Reynolds number kappa-epsilon turbulence model was developed for predicting transitional boundary layer flows under conditions characteristic of gas turbine blades.
Abstract: A modified form of the Lam-Bremhorst low-Reynolds number kappa-epsilon turbulence model was developed for predicting transitional boundary layer flows under conditions characteristic of gas turbine blades. The application of the model to flows with pressure gradients is described. Tests against a number of turbine blade cascade data sets are included. Some additional refinements of the model that were made in recent months are explained.
1 citations