The humidity effect on air flow rates in a critical flow venturi nozzle

Experimental and numerical studies on self-excited periodic oscillation of vapor condensation in a sonic nozzle

“…However, two independent high-accuracy humidity experiments by Lim [8] in 2011 and Chahine [14] in 2013 showed that all experimental data were less than the ones obtained with correction equations. The most likely reason is that the mass flow-rate will be reduced by the complex diverse condensation phenomenon.…”

“…For the condensation phenomena in a sonic nozzle, Aschenbrenner firstly researched and thought that the condensation does not affect the moist air flow-rate of a sonic nozzle [7]. The humidity correction factor without vapor condensation was obtained by Lim [8], Aschenbrenner [9], Britton [10], Stewart [11], Li [12] and Mickan [13], respectively. However, there exist considerable errors among these correction equations.…”

Feature Extraction of Oscillating Flow With Vapor Condensation of Moist Air in a Sonic Nozzle

“…The sonic nozzle is widely used to measure mass flow rate [1]- [2]. The discharge coefficient is a crucial performance parameter for ISO 9300 sonic nozzle which is affected by humidity (by Li [3], Lim [4], Chahine [5]), roughness (by Anthony [6], Alper [7], Wang [8]), geometry (by Park [9], Kim [10]) and vapor condensation (by Li [11], Ding [12]- [13]). The non-equilibrium condensation in sonic nozzle can result in the lower measurement accuracy, due to both steady and unsteady flow which is caused by the supercritical heat addition, namely thermal choking [14], depending on the inlet stagnation condition [15], especially subcooled temperature or humidity of the moist gas.…”