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Convection zones comprise hot, light, upwelling fluid; and cold, dense, downwelling fluid. Ergo, convection zones are characterized by two types of fluids, having (two) separate temperatures, at every altitude / depth. Convection zones must be mathematically modeled accordingly. The following figure sketches a star's temperature profile (T vs. r), qualitatively indicating a convection zone, with steep (supra-adiabatic) overall average temperature gradient, spanning the distance between an interior, and another exterior, region wherein the temperature profile is shallow (sub-adiabatic), and so stable against convection. Upon reaching the convection zone, fluid rises along the "hot" adiabat to the top of the zone, whereat it cools, and then sinks along the "cold" adiabat to the bottom of the zone, whereat it (re-)heats, etc. Convection zones form natural heat engines. Their two-fluid character defines their properties; they must be mathematically modeled commensurately. Temperature-dependent density contrast (δρ) determines the relative buoyancy force, counteracted by viscosity between the cells, which depends upon velocity contrast (δv) and characteristic cell size; mass continuity (δ(ρv)=0) helps solve the system for the unknown variables.
66.235.38.214 ( talk) 14:19, 20 October 2012 (UTC)
I hate to call a university link unreliable. But the first link gives a discussion of convection that is flat out wrong. What is being described is conduction, not convection.
Remove the link? -- Yaush ( talk) 23:50, 24 September 2013 (UTC)
This
level-5 vital article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||
|
Convection zones comprise hot, light, upwelling fluid; and cold, dense, downwelling fluid. Ergo, convection zones are characterized by two types of fluids, having (two) separate temperatures, at every altitude / depth. Convection zones must be mathematically modeled accordingly. The following figure sketches a star's temperature profile (T vs. r), qualitatively indicating a convection zone, with steep (supra-adiabatic) overall average temperature gradient, spanning the distance between an interior, and another exterior, region wherein the temperature profile is shallow (sub-adiabatic), and so stable against convection. Upon reaching the convection zone, fluid rises along the "hot" adiabat to the top of the zone, whereat it cools, and then sinks along the "cold" adiabat to the bottom of the zone, whereat it (re-)heats, etc. Convection zones form natural heat engines. Their two-fluid character defines their properties; they must be mathematically modeled commensurately. Temperature-dependent density contrast (δρ) determines the relative buoyancy force, counteracted by viscosity between the cells, which depends upon velocity contrast (δv) and characteristic cell size; mass continuity (δ(ρv)=0) helps solve the system for the unknown variables.
66.235.38.214 ( talk) 14:19, 20 October 2012 (UTC)
I hate to call a university link unreliable. But the first link gives a discussion of convection that is flat out wrong. What is being described is conduction, not convection.
Remove the link? -- Yaush ( talk) 23:50, 24 September 2013 (UTC)