DIERS Benchmarks.
Case 8 Liquid Water (Two-phase Engine)
The Mach II two-phase engine confirms the results for the single-phase even after the reduction in flow due to inlet pressure loss. The single-phase results have been reprinted to compare the results. It is really amazing to see how both the single and two-phase methods agree with each other. The outlet pressure drops are almost identical. The slight difference in pressure drop is due to the lower two-phase flowrate caused by the inlet pressure drop reducing the relieving pressure.
Mach II Nozzle Results & Piping Restyles
Single-phase Engine Results Download
Liquid Water Flowrate (lbs/hr) Choke (psia) Quality (x) Inlet dP / %Pset Outlet dP /% Pset Piping
803,133 ------- 0 10.97 / 20.87 4.03 / 7.67 4 X 6
803,133 . ------- 0 3.16 / 6.0 4.03 / 7.67 6 X 6
803,133 ------- 0 2.1 / 4.2 4.03 / 7.67 8 X 6
Two-phase Engine Results Download
Liquid Water Flowrate (lbs/hr) Exit (psia) Quality (x) Inlet dP / %Pset Outlet dP /% Pset Piping 779,398 14.7 0 ------- ------- nozzle
678,822 14.7 0 11.2/ 21.4 3.7 / 7.1 4 X 6
740,820 14.7 0 5.3 / 10.1 3.9/ 7.4 6 X 6
749,735 14.7 0 4.4 / 8.3 3.9 / 7.5 8 X 6
DIERS Results
Liquid Water Flowrate (lbs/hr) Exit (psia) Quality (x) Inlet dP / %Pset Outlet dP /% Pset Piping
RRERSP 835,422 14.7 0 ------- ------- nozzle
RRERSP 720,922 14.7 0 8.4 / 16.5 3.9 / 7.6 4 X 6
RRERSP 773,012 14.7 0 1.8 / 3.4 4.0 / 7.6 6 X 6
RRERSP 782,754 14.7 0 0.5 / 1.0 4.0 / 7.7 8 X 6
The inlet and outlet pressure drop for the 4 X 6 agrees with the DIERS results. However, the 6 X 6, and 8 X 6, do not. The reason for this is that the Mach II uses crane to determine the reducer resistance for the inlet piping and it has been shown to be very conservative. See Hooper article on 2K and 3 K method for reducer resistance. Download
