A robust experiment design for the investigation of non-ideal compressible-fluid flow effects

This paper presents the design process of a converging-diverging nozzle operating with a siloxane MM flow in a highly Non-Ideal regime. In particular, the value of the static pressure and of the Mach number are expected to be measured at selected locations within the nozzle. The goal is to extend the database of experimental results concerning non-ideal compressible-fluid flows. The Method of Characteristics (MOC) is used to design a set of possible nozzle layouts which are suitable for the observation of a non-monotonic Mach number trend throughout a supersonic expansion. To verify that the design satisfies the objectives, a Non-Ideal Computational Fluid Dynamics solver is used to carry out a sensitivity analysis of the Mach number by considering the aleatory uncertainties that necessarily affect the nominal operating conditions. The most robust layout, with respect to the considered uncertainties, is then chosen among a four different configurations. The selected nozzle will be eventually employed within an experimental test rig to collect data regarding Non-Ideal flows.