APPD

: an abbreviation for arbitrary pressure pulsation generating device

C

: sonic conductance, dm³/(s・MPa)

E

: input voltage of the servo valve, V

E_ave

: average input voltage of the servo valve, V

E_amp

: amplitude of the input voltage of the servo valve, V

f

: frequency, Hz

P

: pressure, Pa

P₀

: upstream pressure, MPa (G)

P₁

: pressure at pipe inlet, Pa

P₂

: pressure at pipe outlet, Pa

P_amp

: amplitude of pressure pulsation

Q

: volumetric flow rate, dm³/s (ANR)

UFG

: an abbreviation for unsteady flow rate generator

t

: time, s

θ

: air temperature, K