Free Convection Heat Transfer Coefficients From Rectangular Vertical Fins

Vertical, rectangular, finned surfaces are used to effect heat transfer on much equipment. Lack of data showing the effect of various fin geometries on free-convection heat transfer prompted this experimentation. The results provide preliminary design data. For a given temperature, an optimum value of the ratio of fin height to the distance between fins is indicated. The way this ratio varies with fin temperature is also given.

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Optimum Arrangement of Rectangular Fins on Horizontal Surfaces for Free-Convection Heat Transfer

Journal of Heat Transfer ◽

10.1115/1.3449648 ◽

1970 ◽

Vol 92 (1) ◽

pp. 6-10 ◽

Cited By ~ 114

Author(s):

Charles D. Jones ◽

Lester F. Smith

Keyword(s):

Heat Transfer ◽

Free Convection ◽

Design Method ◽

Convection Heat Transfer ◽

Transfer Coefficients ◽

Maximum Heat ◽

Heat Transfer Coefficients ◽

Maximum Heat Transfer ◽

Optimum Arrangement ◽

Free Convection Heat

Experimental average heat-transfer coefficients for free-convection cooling of arrays of isothermal fins on horizontal surfaces over a wider range of spacings than previously available are reported. A simplified correlation is presented and a previously available correlation is questioned. An optimum arrangement for maximum heat transfer and a preliminary design method are suggested, including weight considerations.

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Finite Element Predictions of Free Convection Heat Transfer Coefficients of Simulated Electronic Circuit Boards

Journal of Electronic Packaging ◽

10.1115/1.3226517 ◽

1989 ◽

Vol 111 (2) ◽

pp. 129-134 ◽

Cited By ~ 3

Author(s):

C. Rajakumar ◽

D. Johnson

Keyword(s):

Heat Transfer ◽

Finite Element ◽

Convection Heat Transfer ◽

Circuit Board ◽

Convection Heat ◽

Transfer Coefficients ◽

Heat Transfer Coefficients ◽

Heating Surfaces ◽

Free Convection Heat ◽

Microelectronic Components

A numerical simulation of the buoyancy-induced flow around microelectronic components mounted on a circuit board has been performed using the finite element method. The circuit board is modeled by a vertical plate on which rectangular strip heating surfaces are mounted. Computations have been performed in two-dimensional plane applying a simplifying assumption that the circuit board and the strip heating surfaces are infinitely long. The Navier-Stokes, the flow continuity and the energy equations for laminar flow have been considered in the finite element discretizations. Results of the computations are presented in the form of temperature contour plots and velocity vector plots in the flow field. The convection heat transfer coefficients at the surface of the microelectronic components are presented as a function of their height. The convection coefficients computed have been compared with experimental correlations of free convection heat transfer found in the literature.

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Why heat transfer coefficients are unnecessary and undesirable, and how heat transfer problems are solved without them.

10.21203/rs.3.rs-41275/v1 ◽

2020 ◽

Author(s):

EUGENE ADIUTORI

Keyword(s):

Heat Transfer ◽

Free Convection ◽

Thermal Behavior ◽

Convection Heat Transfer ◽

Nonlinear Function ◽

Convection Heat ◽

Transfer Coefficients ◽

Heat Transfer Coefficients ◽

Transfer Problems

Abstract Heat transfer coefficients (h) are unnecessary and undesirable . They are unnecessary because heat transfer problems are readily solved without them. They are undesirable because they greatly complicate problems that concern nonlinear thermal behavior. In order to understand why heat transfer coefficients are unnecessary and undesirable, it is necessary to know precisely what h is. The nomenclature in every heat transfer text should state “ h is a symbol for q/ D T ”. (Note that q = h D T and h = q/ D T are identical .) Problems in convection heat transfer are conventionally solved using q, h, and D T —ie using q, q/ D T, and D T . It is self-evident that any problem that can be solved using q, q/ D T , and D T can also be solved using only q and D T . Therefore h (ie q/ D T ) is unnecessary. h (ie q/ D T ) is undesirable because, when q is a nonlinear function of DT (as in free convection, condensation, and boiling), h (ie q/ D T ) is a third variable , and it greatly complicates problem solutions. The text includes example problems that support the conclusion that h (ie q/ D T ) is unnecessary and undesirable.

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