Experiments to study the gaseous discharge and filling of vessels

Two experiments are described that have been developed to demonstrate the fundamentals of unsteady, compressible flow. The experiments involve the discharge of gas from a pressurized vessel and the filling of an initially evacuated vessel. The hardware, software, and procedures for the experiments are summarized. In addition, theoretical solutions for the entire vessel filling and discharge process (choked and unchoked operation) are developed using both adiabatic and isothermal models of the processes. Example measurements from the discharge and filling experiments are presented and compared to the adiabatic and isothermal theories. The data are found to agree well with the theoretical predictions and follow the expected trends with respect to the rapidity of the processes.