NomenclatureΒΆ

General conventions for variable names:

  • Symbol or numeric subscripts are not separated by underscores: Vx, Alpha1.

  • Accents and descriptive subscripts are separated by underscores: Vt2_rel, mdot_stall.

  • Stagnation quantities are denoted by a subscript letter oh: Po, ho_rel.

  • Depending on context, concatenation of symbols is either: a product, such as rhoVx; or a stack along the first array dimension, like xrt.

The yaw angle, Alpha or \(\alpha\), is defined as the angle between the flow direction and the meridional direction:

\[\alpha = \arctan\left(\frac{V_\theta}{V_m}\right)\]

where \(V_\theta\) is the tangential and \(V_m\) the meridional components of flow velocity. In the rotating frame, the relative yaw angle, Alpha_rel or \(\alpha^\mathrm{rel}\), is defined as:

\[\alpha^\mathrm{rel} = \arctan\left(\frac{V_\theta^\mathrm{rel}}{V_m}\right)\]

The pitch angle, Beta, is defined as the angle between the meridional flow direction and the axial direction:

\[\beta = \arctan\left(\frac{V_r}{V_x}\right)\]

where \(V_r\) is the radial velocity component. Throughout the code, angles have units of degrees.

Symbol

Quantity

Units

a

Acoustic Speed

m/s

cp

Specific heat capacity at constant pressure

J/kg/K

cv

Specific heat capacity at constant volume

J/kg/K

gamma

Ratio of specific heats

h

Specific enthalpy

J/kg

mu

Dynamic viscosity

kg/m/s

P

Pressure

Pa

Pr

Prandtl number

rgas

Specific gas constant

J/kg/K

rho

Mass density

kg/m^3

s

Specific entropy

J/kg/K

T

Temperature

K

u

Specific internal energy

J/kg

x

Axial coordinate

m

r

Radial coordinate

m

t

Tangential coordinate

rad

m

Meridional coordinate

m

Omega

Shaft angular velocity

rad/s

y

Cartesian vertical coordinate

m

z

Cartesian horizontal coordinate

m

spf

Span fraction coordinate

V

Velocity

m/s

mdot

Mass flow rate

kg/s

Alpha

Yaw angle

deg

Beta

Pitch angle

deg

U

Blade speed

m/s

e

Specific total energy

J/kg

I

Rothalpy

J/kg

Ma

Mach number

A

Area

m^2

zeta

Surface distance coordinate

m