An analysis for jet discharging tests with stop valve by PRTHRUST-J1 code

An analysis was made by PRTHRUST-J1 code for the jet discharging tests with stop valve performed in the preliminary pipe rupture test. In this analysis, the stop valve which was installed between the first elbow and the discharging end was assumed to open linearly with time. The time required for valve opening was decided from the time variation of pressure in the discharging nozzle. The analysis was performed for the jet discharging tests using the discharging nozzles of 2 in. and 3 in. in diameter by varying the value of discharging coefficient. The analytical blowdown thrust force and pressure in the discharging nozzle were compared with experimental results. Qualitative agreement was found between both of the blowdown thrust forces. It was also found that generally speaking the blowdown thrust forces obtained from the experiments were between the analytical results of discharging coefficient of 1.0 and 0.6. The discharging coefficient which was best coincident with experimental results could not, however, be obtained from this analysis. (author)