Abstract
This thesis describes a study undertaken to investigate the characteristics of a small high pressure gas source discharging under quasi-steady conditions. The design and construction of an experimental facility, associated instrumentation, and computer controlled data acquisition system is described. Experimental results are presented for gas discharge, at mass flow rates between 14 g/s and 70 g/s, from storage pressures up to 30.0 MN/m2; the gas storage temperature is nominally 293 K in all cases. Digital simulation models for the gas source and for a supply manifold downstream of a pressure regulator are proposed based on simplified step-by-step approaches using approximate thermodynamic relationships for real gases. Nitrogen gas only is considered, but similar methods could be applied-for Helium or other suitable gases. The quadratic functions used, derived from comprehensive published data, are shown to be adequate to provide agreement within 8% between the computer simulations and experimental results. The complex heat transfer process can be further simplified in the case of the-supply manifold by, for instance, the use of ideal gas equations; it is considered, however, that the simulation model proposed for the gas storage vessel represents the minimum complexity necessary to obtain reliable predictions of performance during discharge.