Pressure, regime, then flow

Set the pressures first. The regime says choked or subsonic. Flow uses that regime. Gauge pressure adds 1.013 bar to become absolute.

PressureUpstream pressure P1 (bar)Downstream pressure P2 (bar)Pressure unitPressure basis

Upstream temperature T1 (K)Temperature unit

Critical ratio bSonic conductance C (dm3/(s·bar))

Worked example

Pressure ratio 0.285714

ratio = P2 / P1 after conversion to absolute bar

Flow regime choked

Choked: P2/P1 is at or below b, so the mass-flow elliptic factor is 1.

choked when P2/P1 <= b, otherwise subsonic

Normal flow 4200 normal L/min

Q_N = 600 * C * P1 * sqrt(293.15 / T1), P1 in bar and T1 in kelvin

Mass flow is omitted because reference density or reference temperature is blank. Enter rho0 and T0. A blank is not the same as 0.

Effective area 5

S about 5.0 * C

Cv 1.136364

Cv about C / 0.88

Pressures are converted to bar. Gauge adds 1.013 bar to reach absolute. Temperatures are converted to kelvin. rho0 and T0 stay blank until you enter them.

Flow inputsReference density rho0Reference temperature T0 (K)

Pressure, regime, then flow

Worked example

Worked examples

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