Document jBvZZGv44oXvMYy01dg4D3p5O
12 .
CHAPTER 2
4949 Guide
Direct-current (as adjective) Electromotive Force............... Feet per minute....................... Feet per second....................... Foot.............................................
Foot-pound............................... Foot-pound-second (system). Freezing point......................... Gallon..................................... . Gallons per minute...........
.d-c .emf .fpm . .fps ...ft
ft-lb . .fps ...fp . gal .gpm
Gallons per second............ Gram.................. Gram-calorie...................... Horsepower............... Horsepower-hour........
gps
....... .g-'cal ............:-hp ...... .hp-hr
Hour. ......................................................................... :................................ ........................... ,hr
Inch.-.......... ...................................... ........... - ................................................................... -"liu
Inch-pound........ ........ ................................................................................. ............m*h
Indicated horsepower..............................
................................... ....................... ; l"P
Indicated horsepower-hour............................
................ ............................... lhp-nr
Kilogram........ Kilowatt........ Kilowatthour. Mass............... Melting point
Meter. Micron.......... Miles per hour. Millimeter....... Minute.............
Molecular weight............ Mol........ ......................... Ounce.................. .............. Pound.................... ......... Pounds per square inch:
Pounds per square.inch, gage. .... Pounds, per square inch, absolute. Revolutions per minute........ ......... Revolutions per second............... Second..................................................
Specific gravity. Specific heat.... Square foot....... Square inch.... Watt?................... Watthour. i-----
...kg .. .kw kwhr .mass .. mp
........m M () .... mph .. .min
. min.
mol. wt .... mol ..........oz ..........lb ........psi
psig . psia . rpm . .rps . sec
..:.sp gr .. .;sp ht ... .sq ft.
. .sq in. ........ . .w ..... whr
SYMBOLS
' --
A letter symbol is a single character, with subscript or .superscfipt if required, used to designate a physical magnitude in mathematical-equa tions and expressions. Two or more symbols together always represent a_ product. The following have been compiled from a selected list of approved standards. Additional symbols, and. variations in the standard symbols
> Letter' Symbols [or Mechanics of Solid Bodies, Z10.3-1942, and Letter Symbols for Heat and Thermodynamics,. ZlO.4-1943 {American Standards Association). -
Abbreviations and Symbols
13
found necessary in the individual-chapters will'be found in a list at the end of Chapters 3, 4, 5, 7, 15, 16, 39, and 41.
Acceleration,.due to gravity................................ ........................................................... . .g Acceleration, linear.................................................................. ........................ ................... 0 Area......................... r..............................................!................................................................... A Change in specific volume during vaporization.............................................................. Density, Weight per unit volume; Specific weight.............. ........ ................dor p (rho).
v
Distance, linear................................................................................................
8
Dry saturated vapor, Dry saturated gas at saturation pressure and temperature,
vapor in contact with liquid.......... ........................ ......................... .. Subscript g
Efficiency.:.......................... ......... .................... ............;................._________________ij
Elevation above some datum........................... .......... ............
........................z z
Emissivity........ .....................................................................................
e
Energy in general; work, total; work, molal......................................................................E
Entropy. (The capital should be used for any weight, and the small letter for........
unit weight)..................................... :................................................................. ......... S or s
Force, total load..........................................................................................................................p
Gas Constant, in equation pV = nRT............. ....... .......... ................................. ... ..R
Head..................................................................................................................................H or h Heat content; Total heat, Enthalpy. (The capital should be used for any
weight and the small letter for unit weight).: ..........i..................... H or h
Heat content of saturated liquid, Total heat of saturated liquid, Enthalpy of saturated liquid, sometimes called heat of the liquid................................... ......hf
Heat content of dry saturated vapor, Total heat of dry saturated vapor, En
thalpy of dry-saturated vapor.......................................................................................h
Heat of vaporization at constant pressure...............................................................Z, or Aft
Hydraulic radius.....................................i...............................................................................rh
Internal energy, Intrinsic energy. (The capital should be used for any weight
and the small letter for unit weight).................................................................... U or u
Length of path of heat flow, thickness........................................................ ..
L
Load, total......................................................................................... ........................................ jy Mechanical efficiency..................... ...................................... ............................. . * ' ^ -Mechanical equivalent of heat........................................................... .................................j Power, Horsepower, Work per unit time..!.............................................................. ..P Pressure, Absolute pressure, Gage pressure, Force per unit area.
Quantity (total) of fluid, water, gas; heat; Quantity by. volume; Total quantity . -
of heat transferred.................................................................................................
q
Quality of steam, Pounds of dry steam per pound of mixture.......:........ .............. x . Reynolds Number................................................................ ............... WRe
Saturated liquid at saturation pressure and temperature, Liquid in contact with
r, ................ ;......................................................'................... .......... .Subscript {
Specific heat............................. ...................
.'................ I
... c
Specific heat at constant pressure...............
. .. ............................. ... .c
Specific heat at constant volume..!.
........
\:c*
Specific volume, Volume per unit weight, Volume per unit
........ ........ . //..v
Temperature (ordinary) E or.C.T (Theta is used;preferably only when l is used'
for Time in.the.same discussion).......... ..
V............................. .t or 0 {theta)
Temperature (absolute) F abs or K. (Capital theta is used preferably only when
small theta is used for ordinary temperature)......................... T or O {capital theta)
Thermal'conductance4: heat transferred per (unit time) (degree)............... ..........C
* Terms ending vntp designate properties independent of si*e or shape, sometimes called specific propcrties. Examples: conductivity, resistivity. Terms ending.cnee designate quantities-depending not only on the material, but also upon sue and shape, sometimes called total quantities'. Examples: conductance,
transmittance. Terms ending ion designate rate of heat transfer. Examples: conduction, transmission /S