Heat transfer Flashcards
1
Q
Heat energy consists of
A
(Ta-Tb)
A(area)
t (time)
Thermal resistance (R)
2
Q
Heat energy (H)
A
(Ta-Tb) x t x A / R
unit: joul
3
Q
rate of heat energy or power
A
P= H/t
= (Ta-Tb) x A /R
unit: Watt
4
Q
rate of heat energy per unit area (w)
A
q= H/ t x A
= (Ta-Tb)/R
unit : watt/m2
5
Q
Thermal resistance (solid)
A
R= x/k
x= thickness
K= w/mk
6
Q
Thermal resistance (fluid)
A
R= 1/h
h= heat transfer coefficient
