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Effects of Contamination and Power‐Law Fluid Viscosity on Heat Transfer Phenomena of Spherical Bubbles
Author(s) -
Nalajala Venkata Swamy,
Kishore Nanda
Publication year - 2014
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201400004
Subject(s) - nusselt number , mechanics , power law , momentum (technical analysis) , power law fluid , heat transfer , thermodynamics , conservation of mass , first law of thermodynamics , law , classical mechanics , physics , mathematics , reynolds number , flow (mathematics) , statistics , finance , political science , turbulence , economics
Abstract Heat transfer phenomena of spherical bubbles in unbounded contaminated power‐law liquids were numerically studied within the framework of a stagnant spherical cap model by solving the governing conservation equations of mass, momentum, and energy using a segregated approach. The governing equations were solved with the semi‐implicit method for pressure‐linked equations. The momentum terms were discretized by quadratic upstream interpolation for convective kinematics. Isotherm contours reveal that the thermal boundary layer becomes thinner with the decreasing power‐law index and/or the stagnant cap angle. The surface Nusselt number distributions indicate a sudden decrease at the leading edge of the stagnant cap and this reduction is found to be a strong function of all pertinent parameters. The average Nusselt numbers of contaminated spherical bubbles rise with the smaller cap angle and/or the lower power‐law index.