Verification Case 20
PRODUCT: AFT Arrow
MODEL FILE: AroVerify20.ARO
REFERENCE: Mohinder L. Nayyar, Piping Handbook, Seventh Edition, McGraw-Hill, New York, 2000, Page B.399, Example B8.6
GAS: Air
ASSUMPTIONS: 1) Adiabatic flow, 2) Perfect gas
RESULTS:
Parameter | Nayar | AFT Arrow |
M1– Mach number at valve | 0.235 | 0.235 |
P1– Pressure at valve (psia) | 661.96 | 662.27 |
DISCUSSION:
The problem assumes an unusual inlet boundary condition where the flow rate is known and the stagnation temperature. AFT Arrow uses the static temperature at the inlet because it is typically associated with a flow rate. To match the 120 F stagnation temperature, the inlet static temperature was iterated a few times.
The conditions result in sonic choking at the discharge.
The predictions agree very closely.