Premium
Prandtl number effect on combined free and forced laminar convection in the thermal entrance region of a horizontal tube
Author(s) -
Chou F. C.,
Hwang G. J.
Publication year - 1988
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450660322
Subject(s) - prandtl number , nusselt number , mechanics , vorticity , laminar flow , forced convection , heat flux , physics , tube (container) , natural convection , thermodynamics , classical mechanics , convection , materials science , heat transfer , reynolds number , vortex , turbulence , composite material
This note presents the Prandtl number effect on combined free and forced laminar convection in the thermal entrance region of a horizontal tube by a numerical vorticity‐velocity method. The tube wall is heated with a uniform wall heat flux. Vorticity‐velocity governing equations in cylindrical coordinates and an evaluation of boundary vorticity on the tube wall are presented along with a numerical method of solution. Local Nusselt number variations are shown for Pr = 100 and 10 and compared with the existing data for Pr → ∞. It is observed that the large Prandtl number assumption is valid for Pr = 10 within a difference of 4% at Ra = 1 × 10 5 . The numerical results are compared against the available experimental data with good agreement.