Symbol Flow Variable Or, Constant Represented

Ghosh - 550 Page 2 11/29/00

List of Engineering Symbols

Symbol Flow Variable or, Constant Represented

D Diameter

D/Dt Total, Material or, Substantial Derivative

E Energy

FB Body Force

FD Drag Force

FL Lift Force

FS Surface Force

h Enthalpy

i Electrical Current

K Minor Loss Coefficient (in pipe flow calculations)

L Characteristic Length in a fluid flow

Le Entrance length (or, Equivalent Length in pipe

flow calculations)

M Mach Number

N Extensive Property

P Linear Momentum

Q Volumetric Flow Rate (or, Heat Addition to a

system)

R Electrical Resistance, or, Radius

Re Reynolds Number

Rfl Flow Resistance

Rth Thermal Resistance

S Entropy

U Internal Energy

V Volume

V Magnitude of Velocity

Vr r-component of the velocity vector

Vt Terminal Velocity

Vq q-component of the velocity vector

Vz z-component of the velocity vector

W Work done on a system

b Span of an airplane wing

c Speed of Sound (or, chord of an airplane wing)

d Diameter

e Specific Energy

f Friction Factor used in the Moody Diagram

g Acceleration due to gravity

h Specific Enthalpy (or, height variable)

hl Head Loss

hl,maj Major Head Loss

hl,min Minor Head Loss

m Mass

p Static Pressure

p0 Total Pressure (i.e., Stagnation Pressure)

q Dynamic Pressure = rV2/2 (or, Strength of a

Source)

r Cylindrical Coordinate variable (or, radius)

s Distance variable (or, Tangential Coordinate

variable)

t Time (or, Tangential Coordinate axis direction)

u x-component of the velocity vector (or, specific

internal energy)

v y-component of the velocity vector

w z-component of the velocity vector

x Cartesian Coordinate variable

y Cartesian Coordinate variable

z Cartesian (or Cylindrical ) Coordinate variable

a  Kinetic Energy Flux Coefficient (or, angle of attack

of an airfoil)

d Boundary Layer Thickness

d* Displacement Thickness

e Normal Strain (or, Roughness Factor)

e/D Relative Roughness (for pipe flow calculations)

f Velocity Potential

g Shear Strain

h  Intensive Property (or, non-dimensional variable,

h = y/d)

m  Absolute or, Dynamic Viscosity or, Strength of a

Doublet

u Kinematic Viscosity

Q  Cylindrical Coordinate variable (or, Momentum

Thickness)

r Density

s Normal Stress

t Shear Stress

tw Wall Shear Stress

w Angular (or, Rotational) Velocity

Y Stream Function

D  Difference Operator (or, very small change

inducator)

G Circulation (or, Strength of a Vortex)

å Summation Symbol

W Vorticity (= 2w)