Author
Stuart W. Churchill
Bio: Stuart W. Churchill is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Laminar flow & Turbulence. The author has an hindex of 32, co-authored 172 publications receiving 7392 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a simple expression for the space-mean Nu (or Sh ) for all Ra and Pr (or Sc) in terms of the model of Churchill and Usagi was developed.
1,618 citations
TL;DR: In this article, a simple empirical expression for the mean value of Nu over the cylinder for all Ra and all Pr is developed in terms of the model of Churchill and Usagi.
1,162 citations
TL;DR: In this article, a single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available.
Abstract: A single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available. This expression is a lower bound (except possibly for RePr < 0.2); free-stream turbulence, end effects, channel blockage, free convection, etc., may increase the rate. In the complete absence of free convection, the theoretical expression of Nakai and Okazaki may be more accurate for RePr < 0.2. The correlating equation is based on theoretical results for the effect of Pr in the laminar boundary layer, and on both theoretical and experimental results for the effect of Re. The process of correlation reveals the need for theoretical results for the effect of Pr in the region of the wake. Additional experimental data for the effect of Pr at small Pe and for the effect of Re during the transition in the point of separation are also needed.
849 citations
TL;DR: The expression Y = (1 + Zn)1/n where Y and Z are expressed in terms of the solutions for asymptotically large and small values of the independent variable is shown to be remarkably successful in correlating rates of transfer for processes which vary uniformly between these limiting cases as discussed by the authors.
Abstract: The expression Y = (1 + Zn)1/n where Y and Z are expressed in terms of the solutions for asymptotically large and small values of the independent variable is shown to be remarkably successful in correlating rates of transfer for processes which vary uniformly between these limiting cases. The arbitrary exponent n can be evaluated simply from plots of Y versus Z and Y/Z versus 1/Z. The expression is quite insensitive to the choice of n and the closest integral value can be chosen for simplicity. The process of correlation can be repeated for additional variables in series. Illustrative applications are presented only for flow, conduction, forced convection, and free convection, but the expression and procedure are applicable to any phenomenon which varies uniformly between known, limiting solutions.
784 citations
TL;DR: In this paper, a correlating equation for assisting convection was developed by combining correlating equations for pure free and pure forced convection, based on laminar boundary-layer theory for an isothermal, vertical plate.
Abstract: A correlating equation for assisting convection was developed by combining correlating equations for pure free and pure forced convection. These component equations are based on laminar boundary-layer theory for an isothermal, vertical plate. Theoretical values for assisting convection indicate that the third root of the sum of the third powers gives the best representation, as contrasted with the choice and rationalization of the second or fourth power by prior investigators.
This expression was modified by the addition of a limiting value Nuo to obtain a better representation below the domain of boundary-layer theory and was generalized for uniform heating and for spheres and horizontal cylinders by the appropriate choice of the characteristic length.
257 citations
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TL;DR: In this paper, the authors used the finite volume technique to solve the governing equations of heat transfer and fluid flow due to buoyancy forces in a partially heated enclosure using nanofluids.
1,783 citations
TL;DR: In this paper, a simple expression for the space-mean Nu (or Sh ) for all Ra and Pr (or Sc) in terms of the model of Churchill and Usagi was developed.
1,618 citations
TL;DR: In this article, a simple empirical expression for the mean value of Nu over the cylinder for all Ra and all Pr is developed in terms of the model of Churchill and Usagi.
1,162 citations
TL;DR: In this article, a single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available.
Abstract: A single comprehensive equation is developed for the rate of heat and mass transfer from a circular cylinder in crossflow, covering a complete range of Pr (or Sc) and the entire range of Re for which data are available. This expression is a lower bound (except possibly for RePr < 0.2); free-stream turbulence, end effects, channel blockage, free convection, etc., may increase the rate. In the complete absence of free convection, the theoretical expression of Nakai and Okazaki may be more accurate for RePr < 0.2. The correlating equation is based on theoretical results for the effect of Pr in the laminar boundary layer, and on both theoretical and experimental results for the effect of Re. The process of correlation reveals the need for theoretical results for the effect of Pr in the region of the wake. Additional experimental data for the effect of Pr at small Pe and for the effect of Re during the transition in the point of separation are also needed.
849 citations