Computational Heat Transfer in Heat Exchanger Analysis and Design (Invited)

2005 ◽  
Author(s):  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Rapid Development ◽  
Flow Fields ◽  
Analysis And Design ◽  
Recirculating Flow ◽  
Numerical Solution Methods ◽  
Solution Methods ◽  
Laminar And Turbulent Flow ◽  
Grid Points

Rapid development of computer capacity and advances in numerical solution methods for the governing equations of fluid flow and heat transfer have enabled CFD (computational fluid dynamics) methods to gradually become useful tools in research and development, engineering design and analysis of heat transfer equipment. However, turbulence modelling still presents a problem as accurate and reliable predictions of flow separation, reattachment, impingement and recirculating flow fields are requested. For heat exchangers both laminar and turbulent flow fields are of significance and in addition the geometries are complex, of small dimensions sometimes and turbulators or enhanced surfaces are applied. Still the demands on computers are strong as analysis of full scale equipment requires a huge amount of grid points and the computation times are long. The present paper concerns current CFD methods for thermal problems in analysis and design of heat exchangers. Application examples are presented and associated problems and limitations are discussed.

A Survey of Heat Transfer in Separated and Reattached Flows

2000 ◽  
Vol 53 (8) ◽  
pp. 219-235 ◽  
Author(s):  
Terukazu Ota
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Exchangers ◽  
Plane Channel ◽  
Review Article ◽  
Sudden Expansion ◽  
Expansion Tube ◽  
Geometric Configurations ◽  
Laminar And Turbulent Flow ◽  
Flow Configurations

Heat and mass transfer in the separated, reattached, and redeveloping regions of incompressible or compressible flow is very important in relation to many types of heat exchangers. There have been numerous works published describing these flows for a wide variety of geometric configurations, In the present article, a survey is made of published studies of heat transfer in the separated, reattached, and redeveloping regions of incompressible flow around or in a wide variety of flow configurations. Flow configurations cited in the article are the downward facing step, the sudden expansion plane channel, the abrupt expansion tube, the blunt flat plate, the longitudinal blunt circular cylinder, and the surface mounted obstacle. The laminar and turbulent flow cases using both experimental and numerical methodologies are reviewed. This review article includes 268 references.

Inclination Angle Optimization for “Inclined Projected Winglet Pair” Vortex Generator

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Oneissi ◽  
Charbel Habchi ◽  
Serge Russeil ◽  
Daniel Bougeard ◽  
Thierry Lemenand
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Inclination Angle ◽  
Heat Exchangers ◽  
Vortex Generator ◽  
Working Fluid ◽  
Static Mixers ◽  
Thermal Enhancement ◽  
Laminar And Turbulent Flow ◽  
Inclination Angles

Abstract Vortex generators (VG) are widely used in multifunctional heat exchangers/reactors for augmenting the heat transfer from fin plates to the working fluid. In this study, numerical simulations for longitudinal VGs are performed for both laminar and turbulent flow regimes. The shear-stress transport (SST) κ–ω model is used for modeling turbulence. Inclination angle for a new streamlined VG configuration called inclined projected winglet pair (IPWP) was varied to study the effect of this angle on the heat transfer enhancement and pressure drop. Response surface methodology (RSM) was used to deduce the inclination angle effects on heat transfer, pressure drop, and vorticity from both local and global points of view. Such study highlights the optimization for this VG configuration for better heat transfer intensification, based on thermal enhancement factor (TEF). Finally, it is found that the VG with inclination angle ranging from 30 deg to 35 deg exhibits the best global performance compared to other inclination angles. This type of studies is important for the enhancement of the thermal performance of heat exchangers and static mixers in various engineering applications.

Numerical Calculation of Convective Heat Transfer Between Rotating Coaxial Cylinders With Periodically Embedded Cavities

1992 ◽  
Vol 114 (3) ◽  
pp. 589-597 ◽  
Author(s):  
T. Hayase ◽  
J. A. C. Humphrey ◽  
R. Greif
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Finite Volume Scheme ◽  
Two Dimensional ◽  
Constant Property ◽  
Analysis And Design ◽  
Coaxial Cylinders ◽  
Recirculating Flow

A numerical study has been performed for the flow and heat transfer in the space between a pair of coaxial cylinders with the outer one fixed and the inner one rotating. Of special interest is the case where either one of the cylinders has an axially grooved surface resulting in twelve circumferentially periodic cavities embedded in it. The ends of the cylinder are bounded by flat impermeable walls that are either fixed to the outer cylinder or rotate with the inner one. Such a geometry is common in electric motors where an improved understanding of thermophysical phenomena is essential for analysis and design. Discretized transport equations are solved for two-dimensional and three-dimensional, steady, constant property laminar flow using a second-order accurate finite volume scheme within the context of a SIMPLER-based iterative methodology. The two-dimensional calculations reveal a shear-induced recirculating flow in the cavities. For supercritical values of the Reynolds number, the three-dimensional calculations show how the flow in a cavity interacts with Taylor vortices in the annular space to enhance heat transfer. Relative to coaxial cylinders with smooth surfaces, for the conditions of this study the transport of momentum and heat is raised by a factor of 1.2 in the case of cavities embedded in the inner cylinder and by a factor of 1.1 in the case of cavities embedded in the outer cylinder.

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