The flexible asymmetric shock tube (FAST): a Ludwieg tube facility for wave propagation measurements in high-temperature vapours of organic fluids

Abstract

(2) the process start-up time of the valve has been found to be between 2.1 and 9.0 ms, (3) preliminary rarefaction wave experiments in the dense vapour of siloxane D 6 (dodecamethylcyclohexasiloxane, an organic fluid) were successfully accomplished up to temperatures of 300 • C, and (4) a method for the estimation of the speed of sound from wave propagation experiments is proposed. Results are found to be within 2.1 % of accurate model predictions for various gases. The method is then applied to estimate the speed of sound of D 6 in the NICFD regime. List of symbols cSpeed of sound The set-up is equipped with a special fast-opening valve, separating the high-pressure charge tube from the lowpressure plenum. When the valve is opened, a wave propagates into the charge tube. The wave speed is measured using a time-of-flight technique employing four pressure transducers placed at known distances from each other. The first tests led to the following results: (1) the leakage rate of 5 × 10 −4 mbar l s −1 for subatmospheric and 5 × 10 −2 mbar l s −1 for a superatmospheric pressure is compatible with the purpose of the conceived experiments,

Analysis of turbulence characteristics in a temporal dense gas compressible mixing layer using direct numerical simulation

“…Since then, works of , Colonna et al (2008), Spinelli et al (2010) and Spinelli et al (2013) enabled the design of shock tubes and test rigs, such as the Test Rig for Organic Vapors (TROVA) at Politecnico di Milano or the Flexible Asymmetric Shock Tube (FAST) built at Delft University of Technology (Mathijssen et al 2015). The experimental proof of rarefaction shock waves remains an active research area.…”

Direct numerical simulations of supersonic turbulent channel flows of dense gases

“…Furthermore, most of the facilities presently under development are thought to provide average pressure and temperature profiles and, in some cases, flow visualizations, but are not expected to provide a detailed description of the turbulence structure, at least in the short term. A review of recent experimental research on dense-gas flows can be found in Spinelli et al (2013) and Mathijssen et al (2015). For these reasons, in this work we choose to investigate wall-bounded turbulent dense-gas flows by means of direct numerical simulations (DNS) of the Navier-Stokes equations, supplemented by suitable thermodynamic and transport property models.…”

A novel self-seeding method for particle image velocimetry measurements of subsonic and supersonic flows

“…There have been a couple of attempts for measuring the flow characteristics of this flow but they have remained on the design step or point measurement such as TU Delft (flexible asymmetric shock tube) 8,9 , Politecnico de Milano (test rig for organic vapors) 10 and by White and Sayma 11 where a closed-loop of organic vapors was designed. One of the important methods for quantitative measurements of flow structures of the desired flow is Particle Image Velocimetry (PIV).…”