Chapter H: H Hysteresis Loss

H

hydrogen (element)

Hagen Poiseuille law

See also FLUID FLOW.

hand

unit of measure used for measuring the height of a horse.

hand =

• 10.16 cm

• 4 in.

hardness of materials

See also Brinell Hardness Number (BHN).

He

helium (element)

heat capacity

See also HEAT TRANSFER.

heat of combustion

See also heat value of a material.

heat of fusion

See also HEAT TRANSFER.

heat of solidification

See also HEAT TRANSFER.

heat of sublimation

See also HEAT TRANSFER.

heat of vaporization

See also HEAT TRANSFER.

HEAT TRANSFER

where

a	= coefficient of linear thermal expansion, length change/unit length/ F
A	= area of contact surface, ft 2
b	= coefficient of cubical expansion, volume change/unit volume/ F
B	= heat energy absorbed, Btu
C	= specific heat, Btu/lb/ F
C P	= specific heat at constant pressure, Btu/lb/ F
C v	= specific heat at constant volume, Btu/lb/ F
d	= depth (thickness), in.
e	= radiation factor
E	= electrical potential, volts
F	= radiation factor, combined for two surfaces
h	= convection coefficient, Btu/hr-ft 2- F
h F	= heat of fusion, Btu/lb
h V	= heat of vaporization, Btu/lb
H	= heat flow, Btu/hr
I	= electric current flow, amperes
k	= conduction coefficient, Btu-in./hr-ft 2- F
L	= length, in.
Q	= flow, ft 3/min
r	= resistance, electrical, ohms
R	= resistance, thermal, hr-ft 2- F/Btu
S	= Stefan Boltzmann constant, 0.174 E ? 08 Btu/hr-ft 2- R 4
t 1	= initial temperature, F
t