Mechanics of Fluids

Table A4.1 (contd.)
Symbol Definition Dimensional
formula
M total mass [M]
M Mach number [1]
M
M
relative molecular mass [1]
′ virtual mass [M]
Mk2 moment of inertia [ML2 ]
m mass [M]
m mass flow rate (Chapter 11) [MT −1 ]
m hydraulic mean depth, A/P [L]
m strength of source or sink (two-dimensional
flow)
[L2T−1 ]
m 2π /wavelength [L−1 ]
N a dimensionless parameter [1]
N rotational speed in rev/s [T−1 ]
n a number [1]
n distance normal to streamline [L]
n Manning’s roughness coefficient (a number) [1]
P perimeter in contact with fluid [L]
P power [ML2T−3 ]
p pressure [ML−1T−2 ]
pa atmospheric pressure [ML−1T−2 ]
pi inertia pressure [ML−1T−2 po stagnation pressure
]
[ML−1T−2 pv vapour pressure
]
[ML−1T−2 p
]
∗ piezometric pressure, p + ϱgz [ML−1T−2 ]
Q discharge (volume/time) [L3T−1 ]
Q heat added [ML2T−2 ]
q discharge divided by width, Q/b [L2T−1 ]
q velocity = (u2 + v2 ) 1/2 (Chapter 9) [LT −1 ]
q heat added divided by mass of fluid [L2T−2 ]
R radius [L]
R gas constant, p/ϱT [L2T−2�−1 ]
R relative velocity in machines [LT −1 ]
Re Reynolds number, ul/v (suffixes l, t, x to
indicate l = l, l = transition length, l = x
respectively)
[1]
r radius [L]
S plan area of wing [L2 ]
S surface area of solid particle [L2 ]
s a distance, especially in direction of flow [L]
s bed slope of open channel [1]
s specific entropy [L2T−2�−1 ]
T torque [ML2T−2 ]
T thrust divided by width of bearing (Chapter 6) [MT −2 ]
T wave period (Chapter 10) [T]
T absolute temperature [�]
T0 t
stagnation temperature (absolute)
interval of time
[�]
[T]
continued overleaf
Appendix 4: Algebraic symbols 681