Premium
Dirichlet problems for laminar forced convection with heat sources and viscous dissipation in regular polygonal ducts
Author(s) -
Cheng K. C.
Publication year - 1967
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690130626
Subject(s) - nusselt number , laminar flow , heat transfer , mechanics , forced convection , convective heat transfer , thermodynamics , boundary layer , heat transfer coefficient , mathematics , physics , reynolds number , turbulence
Abstract The effects of viscous dissipation on fully developed laminar forced convection with heat sources in various regular polygonal ducts under the thermal boundary conditions of uniform wall heat transfer per unit duct length and circumferentially uniform wall temperature are approached by the method of point matching. The method uses the exact solutions to the governing partial differential equations and satisfies the boundary conditions exactly only at selected points. This method complements the method of complex variables for various noncircular geometrical configurations where the velocity and temperature fields are not deducible directly from the boundary equations. The relationship between the average velocity and the average of (grad u ) 2 over the cross section is pointed out. Other useful relationships between heat transfer quantities based on analogy or the observation of the results from literature and present investigation are also pointed out. The numerical results presented can be used to evaluate the effects of viscous dissipation on mean temperature, overall heat transfer rate at the boundary, heat transfer coefficient and Nusselt number. Graphical results for the representative cases are also presented for the heat transfer rate and the Nusselt number.