Laminar forced convection heat transfer of a non-newtonian fluid in a square duct
01 Dec 1977-International Journal of Heat and Mass Transfer (Pergamon)-Vol. 20, Iss: 12, pp 1315-1324
TL;DR: In this article, numerical solutions for laminar heat transfer of a non-Newtonian fluid in the thermal entrance region of a square duct are presented for three thermal boundary conditions.
About: This article is published in International Journal of Heat and Mass Transfer.The article was published on 1977-12-01. It has received 85 citations till now. The article focuses on the topics: Nusselt number & Churchill–Bernstein equation.
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07 Apr 2017
TL;DR: In this article, a comparative study of laminar forced convective heat transfer in the simultaneously developing regions of heated square ducts is performed to make a comparative analysis of Laminar Forced Convective Heat Transfer.
Abstract: Numerical analysis is performed to make a comparative study of laminar forced convective heat transfer in the simultaneously developing regions of heated square ducts. A non-conjugate case, a square duct with single-solid and a square duct with two-solids are selected for the present study. The square duct with two-solids is formed by cladding steel duct over the single-solid Aluminium square duct. The contact resistance between the two solids is neglected. A constant uniform temperature boundary condition is specified over the exterior wall for the ducts and the thermo physical properties of the fluid is assumed to be constant. The non-conjugate case is formed by applying a constant uniform temperature throughout the bulk of the single-solid duct wall. The chtMultiRegionFoam solver in OpenFOAM is used to solve the multiregional heat transfer problem using Finite Volume Method. The results are plotted for longitudinal and transverse distributions of average Nusselt number, local Nusselt number, friction factor and drag coefficient along various curves in the computational domain. The results shows that the average Nusselt number is generally higher for square duct with two solids when compared with single-solid square duct and non-conjugate case.
2 citations
Cites methods from "Laminar forced convection heat tran..."
...Sastri [7] studied the thermal entrance problem in a square duct for laminar flow of non-Newtonian fluid using finite difference method....
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2 citations
1 citations
Journal Article•
TL;DR: In this paper, a non-orthogonal boundary-fitted coordinate transformation method is applied to the solution of steady three-dimensional momentum and energy equations in laminar flow to obtain temperature field and Nusselt numbers in the thermal entry region of straight ducts of different cross sectional geometries.
Abstract: The non-orthogonal boundary-fitted coordinate transformation method is applied to the solution of steady three-dimensional momentum and energy equations in laminar flow to obtain temperature field and Nusselt numbers in the thermal entry region of straight ducts of different cross sectional geometries. The conservation equations originally written in Cartesian coordinates are parabolized in the axial direction and then transformed to the non-orthogonal curvilinear coordinate system to handle arbitrary duct geometries. The transformed equations are discretized using the control-volume finite-difference approach in which the convective and diffusive terms are discretized by the upwind and central difference schemes respectively. The discretization equations are solved by a line-by-line TDMA algorithm. Numerical results of Nusselt numbers and temperature profiles are obtained for constant wall temperature boundary condition and Pr = 6.78.
1 citations
Cites background or result from "Laminar forced convection heat tran..."
...The results obtained by Chandrupatla and Sastri [27] are with no secondary flow and no viscous dissipation effects....
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...The results obtained for square ducts for Newtonian fluids ( T,zNu , T,mNu ) are compared with the numerical solutions of Chandrupatla & Sastri [27] in Tables 4 and 5....
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...The results obtained for square ducts for Newtonian fluids ( T , z Nu , T , m Nu ) are compared with the numerical solutions of Chandrupatla & Sastri [27] in Tables 4 and 5....
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...Chandrupatla and Sastri [27] ignores the effect of Prandtl number on T,mNu by reasoning that it is included in the relevant ( )4X Pr term....
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...Chandrupatla and Sastri [27] ignores the effect of Prandtl number on T , m Nu by reasoning that it is...
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References
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01 Nov 1971
TL;DR: Theoretical laminar flow solutions for heat transfer and flow friction are of importance in the development of compact heat exchangers as discussed by the authors, generally the higher the degree of compactness, the lower is the Reynolds number and the greater is the relevance of the theory solutions.
Abstract: : Theoretical laminar flow solutions for heat transfer and flow friction are of importance in the development of compact heat exchangers. Generally the higher the degree of compactness, the lower is the Reynolds number and the greater is the relevance of the theory solutions. In the report these solutions are compiled for twenty one straight ducts and four curved ducts. Some new analytical solutions are obtained by writing a general computer program for three ducts. Application of the analytical solutions to the gas turbine regenerator is discussed.
101 citations
01 Jan 2019
18 citations
TL;DR: In this paper, the authors used the momentum and energy integral method of von Karman and Pohlhausen to solve the entrance heat transfer problem for a non-Newtonian fluid in a flat duct.
Abstract: The momentum and energy integral method of von Karman and Pohlhausen is used to solve the entrance heat transfer problem for a non-Newtonian fluid in a flat duct. The initial temperature and velocity profiles are assumed to be flat. The fluid is assumed to obey the Ostwald-de Wael model and its physical properties are assumed to be constant. Dimensionless expressions for temperature and velocity profiles are obtained by numerical methods.
The results of this investigation indicate that, similar to the case of Newtonian fluid, the parameters which influence entrance heat transfer are x/b ratio, Reynolds number and Prandtl number, provided these groups are properly defined.
La methode tenant compte du momentum et de l'energie de von Karman et de Pohlhausen est utilisee pour resoudre le probleme de la transmission de chaleur a l'entree d'un conduit plat pour un fluide non-Newtonien. Les profils initiaux de temperature et vitesse sont supposes uniformes. Le fluide est conforme au modele Ostwald-de Wael et ses proprieties sont supposees constantes. Les expressions sans dimensions sont obtenues a l'aide d'analyses numeriques pour les profils de temperature et vitesse.
Les resultats de cette recherche indiquent que, similarement au cas des fluides non-Newtoniens, les parametres influencant la transmission de chaleur a l'entree, sont x/b, Re et Pr en autant que ces groupes son definis adequatement.
16 citations