Fundamentals of Heat and Mass
Transfer - Chap 1
, Stefan-Boltzmann Law - correct answer-E=σT^4 (W/m^2)
This is the upper limit of radiative heat flux, where ε = 1. It is also known as a black body
and is a perfect emitter of radiation heat.
Stefan-Boltzmann Constant - correct answer-σ = 5.67*10^-8 (W/(m^2*K^4))
Conductive heat flux equation - correct answer-q''= -k*A*dT/dx (W/m^2)
k is the thermal conductivity, which can vary across a medium and has units of: W/(m*k)
Convective heat flux equation - correct answer-q''=h(ts-t∞) (W/m^2)
q'' is positive here when heat is transferred from the surface to the fluid, which is what
the two symbols for T are in this equation.
Radiative heat flux - correct answer-E=εσT^4
ε is a radiative property of the surface termed the emissivity.
Emissivity of a surface - correct answer-(ε) the radiative property of a surface, it is unit-
less.
Absolute Surface temperature - correct answer-Ts
Newton's law of cooling - correct answer-q''=h(ts-t∞) (W/m^2)
Convection heat transfer coefficient - correct answer-h: units are W/(m^2*K)
This coefficient depends on conditions in the boundary layer, which are influenced by
surface geometry, the nature of the fluid motion, and an assortment of fluid
thermodynamic and transport properties.
Forced Convection - correct answer-When the flow is caused by external means, such
as by a fan, a pump, or atmospheric winds. p. 6
Transfer - Chap 1
, Stefan-Boltzmann Law - correct answer-E=σT^4 (W/m^2)
This is the upper limit of radiative heat flux, where ε = 1. It is also known as a black body
and is a perfect emitter of radiation heat.
Stefan-Boltzmann Constant - correct answer-σ = 5.67*10^-8 (W/(m^2*K^4))
Conductive heat flux equation - correct answer-q''= -k*A*dT/dx (W/m^2)
k is the thermal conductivity, which can vary across a medium and has units of: W/(m*k)
Convective heat flux equation - correct answer-q''=h(ts-t∞) (W/m^2)
q'' is positive here when heat is transferred from the surface to the fluid, which is what
the two symbols for T are in this equation.
Radiative heat flux - correct answer-E=εσT^4
ε is a radiative property of the surface termed the emissivity.
Emissivity of a surface - correct answer-(ε) the radiative property of a surface, it is unit-
less.
Absolute Surface temperature - correct answer-Ts
Newton's law of cooling - correct answer-q''=h(ts-t∞) (W/m^2)
Convection heat transfer coefficient - correct answer-h: units are W/(m^2*K)
This coefficient depends on conditions in the boundary layer, which are influenced by
surface geometry, the nature of the fluid motion, and an assortment of fluid
thermodynamic and transport properties.
Forced Convection - correct answer-When the flow is caused by external means, such
as by a fan, a pump, or atmospheric winds. p. 6
