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Showing papers by "Ephraim M Sparrow published in 2002"


Journal ArticleDOI
TL;DR: In this paper, the singularities associated with the interaction of a wave front and a boundary may cause a violation of the imposed boundary condition, which may give rise to physically unacceptable results such as a temperature drop due to heating or a temperature rise due to cooling.
Abstract: The hyperbolic diffusion equation is often used to analyze laser heating of dielectric materials and in thermal processing of nonhomogeneous materials. Anomalies in existing solutions of the hyperbolic heat equation are identified. In particular, the singularities associated with the interaction of a wave front and a boundary may cause a violation of the imposed boundary condition. This violation may give rise to physically unacceptable results such as a temperature drop due to heating or a temperature rise due to cooling. The development of appropriate remedies for these happenings is a major focus of this paper. In addition, the unique mathematical features of the hyperbolic heat equation are studied and set forth. Green's function solutions for semi-infinite and infinite bodies are presented. For finite bodies, it is demonstrated that the relevant series solutions need special attention to accelerate their convergence and to deal with certain anomalies

42 citations


Journal ArticleDOI
TL;DR: In this article, a comprehensive experimental investigation has been performed to determine the heat transfer processes occurring within an oven-like enclosure, where the main focus was to identify the thermal response of a load to a number of operational parameters including the radiation surface finish of the load itself and the surface finishes of the oven temperature sensor and the oven walls.

17 citations


Journal ArticleDOI
TL;DR: In this article, the thermal response of the load to the presence of blockages situated either below or above the load was quantified, and the response was only slightly affected by the blockages when they were empty of water.

15 citations


Journal ArticleDOI
TL;DR: In this article, a numerical simulation was performed for the fluid flow and heat transfer in a flow passage consisting of a series of 180° bends connected by straight sections, where the basic passage cross-section geometry is that of a flat rectangular duct.
Abstract: A numerical simulation has been performed for the fluid flow and heat transfer in a flow passage consisting of a series of 180° bends connected by straight sections. The basic passage cross-section geometry is that of a flat rectangular duct. The simulation problem encompassed three-dimensional flows of both fluid and heat and involved the conjugate interaction of thermal phenomena in the fluid and in its bounding wall. The implementation of the numerical model was performed using FLUENT 5.0. Several results of practical interest were deduced from the simulation. With regard to the motivating application, the heating of biofluids prior to their introduction into the human body, local hotspots were found to occur whose presence could be injurious to living cells. The heating of the flowing fluid (a liquid to properly model the biofluid application) was found to be highly nonuniform at low values of the volumetric flowrate of the fluid despite the fact that the bounding walls of the flow passage were unifor...

8 citations