Queries, comments, suggestions? Please contact us.



Area Physics for electrotechnology / Thermodynamics

IEV ref113-04-58

Symbol
Ra

en
Rayleigh number
quantity of dimension 1 characterizing the relative importance of natural convection and thermal conduction, defined by Ra= l 3 ρ 2 c p g α V ΔT ηλ = l 3 g α V ΔT να MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqk0di9Wr=fpeei0di9v8qiW7rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaadkfacaWGHbGaey ypa0ZaaSaaaeaacaWGSbWaaWbaaSqabeaajugabiaaiodaaaGccqaH bpGCdaahaaWcbeqaaKqzaeGaaGOmaaaakiaadogadaWgaaWcbaGaam iCaaqabaGccaaMi8Uaam4zaiaayIW7cqaHXoqydaWgaaWcbaGaamOv aaqabaGccaaMi8ocdaGae8hLdqKaamivaaqaaiabeE7aOjaayIW7cq aH7oaBaaGaeyypa0ZaaSaaaeaacaWGSbWaaWbaaSqabeaajugabiaa iodaaaGccaWGNbGaaGjcVlabeg7aHnaaBaaaleaacaWGwbaabeaaki aayIW7cqWFuoarcaWGubaabaGaeqyVd4MaaGjcVlabeg7aHbaaaaa@63F6@ , where l is a specified length, ρ is mass density, cp is specific heat capacity at constant pressure, g is acceleration of free fall, αv is the cubic expansion coefficient, T is thermodynamic temperature, η is dynamic viscosity, λ is thermal conductivity, and α is thermal diffusivity

NOTE The Rayleigh number is the product of the Grashof number Gr and the Prandtl number Pr, thus Ra = GrPr.


fr
nombre de Rayleigh, m
grandeur sans dimension caractérisant l’importance relative de la convection libre et de la conduction thermique, définie par Ra= l 3 ρ 2 c p g α V ΔT ηλ = l 3 g α V ΔT να MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqk0di9Wr=fpeei0di9v8qiW7rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaadkfacaWGHbGaey ypa0ZaaSaaaeaacaWGSbWaaWbaaSqabeaajugabiaaiodaaaGccqaH bpGCdaahaaWcbeqaaKqzaeGaaGOmaaaakiaadogadaWgaaWcbaGaam iCaaqabaGccaaMi8Uaam4zaiaayIW7cqaHXoqydaWgaaWcbaGaamOv aaqabaGccaaMi8ocdaGae8hLdqKaamivaaqaaiabeE7aOjaayIW7cq aH7oaBaaGaeyypa0ZaaSaaaeaacaWGSbWaaWbaaSqabeaajugabiaa iodaaaGccaWGNbGaaGjcVlabeg7aHnaaBaaaleaacaWGwbaabeaaki aayIW7cqWFuoarcaWGubaabaGaeqyVd4MaaGjcVlabeg7aHbaaaaa@63F6@ , où l est une longueur spécifiée, ρ est la masse volumique, cp est la capacité thermique massique à pression constante, g est l’accélération due à la pesanteur, αv est le coefficient de dilatation volumique, T est la température thermodynamique, η est la viscosité dynamique, λ est la conductivité thermique, et α est la diffusivité thermique

NOTE Le nombre de Rayleigh est le produit du nombre de Grashof Gr et du nombre de Prandtl Pr, soit: Ra = GrPr.


ar
عدد رايليه

de
Rayleigh-Zahl, f

es
número de Rayleigh

fi
Rayleighin luku

it
numero di Rayleigh

ja
レイリー数

pl
liczba Rayleigha

pt
número de Rayleigh

sv
rayleightal

zh
瑞利数

Publication date: 2011-04
Copyright © IEC 2017. All Rights Reserved.