Heat Transfer To Power-law Fluids Research Articles

LAMINAR FLOW AND HEAT TRANSFER IN POWER-LAW FLUIDS FLOWING IN ARBITRARY CROSS-SECTIONAL DUCTS

A numerical method capable of handling three-dimensional transport processes is devised to model the developing steady laminar flow and heat transfer to power-law fluids flowing in ducts of arbitrary but uniform cross section. The governing equations are the general momentum and energy equations parabolized in the axial direction and as such are applicable to flow systems with a predominant flow direction. An orthogonal body-fitted coordinate system is employed to handle complex cross-sectional geometries. The transformed equations are discretized in a finite-difference form, and the resulting algebraic equations are solved by line successive over-relaxation (SOR). For the purpose of testing the algorithms and the computer code, solutions are computed for the well-known case of a Newtonian fluid in a square duct. Excellent agreement with available numerical and experimental results is obtained. The versatility of the code is demonstrated by presentation of flow and heat transfer results for power-law flui...

Laminar Flow and Heat Transfer in Power-Law Fluids Flowing in Arbitrary Cross-Sectional Ducts

Laminar Flow and Heat Transfer in Power-Law Fluids Flowing in Arbitrary Cross-Sectional Ducts

Numerical analysis for forced convection over a flat plate in power law fluids

The analysis of forced convective heat transfer of power-law non-Newtonian fluids from a flat plate is studied. The cases of prescribed surface temperature and prescribed wall heat flux are considered. The results of local heat transfer are obtained by using implicit finite difference scheme to solve the nonsimilarity solution. It was found that local similarity solution is given the low accuracy results for the study of boundary layer heat transfer of power-law fluids.

Unsteady thermal entrance heat transfer of power-law fluids in pipes and plate slits

An instant-local similarity method is proposed to analyze the unsteady state Graetz problems. Unsteady heat transfer for fully-developed laminar flow of power-law non-Newtonian fluids in the thermal entrance region of pipes and plate slits, with viscous dissipation considered, is studied. For the unsteady thermal entrance heat transfer problems, only large Graetz numbers (small normalized axial distance) are concerned and the normalized time from transient up to steady state is of order 10 −1; therefore, the instant-local similarity approach gives results of high accuracy. The effects of the flow index, viscous dissipation and Graetz number on the heat transfer rate are demonstrated with numerical solutions. The corresponding steady-state Graetz problems are studied by the local similarity method whose solutions agree very well with the extended Leveque solutions particularly for large Graetz number and Brinkman number.