G0510406 Characteristics evaluation of ISO9300 type critical nozzle at high Reynolds number

Abstract

We measured the discharge coefficient of critical nozzles using hydrogen gas in high Reynolds number (Re = 2.5 x 10^5 - 1.6 x 10^6). It was confirmed to deviate from the universal curve prescribed in IS09300, and to indicate high value of the critical back pressure ratio. In high Reynolds number, it was not necessary to take large differential pressure in the use of critical nozzle.