Cd	Discharge coefficient
d	Orifice diameter (mm)
e	Eccentricity ratio
f	Approximate solution
Fy	External force (N)
$\overline{h}$	Dimensionless air film thickness
H	Dimensionless groove depth (H = gd/c)
l	Length between orifice to edge
L	Bearing length(mm)
m	Rotor mass (kg)
mt	Mass flow rate (kg/s)
$m_u$	Unbalanced mass (kg)
P	Dimensionless air film pressure
$p_a$	Atmosphere pressure
$p_s$	Supply pressure
u, v	Velocity components in the x and z directions (m/s)
Fx, Fy	Moment in x- and y-direction(N)
$\overline{x}$, $\overline{z}$	Dimensionless coordinates
xGq, yGq	Rotor position
λ	Perturbation frequency ratio
ψ	Attitude angle
θ	Circumference angle
η	Air dynamic viscosity
${\xi }_i$	Delta function
ρ	Air density (kg/m3)
${\rho }_a$	Air density at atmosphere pressure (kg/m3)
∧	Bearing number
${\Lambda }_x$, ${\Lambda }_z$	Dimensionless bearing numbers in the x- and z-direction
κ	Specific heat ratio of air