As a part of the research in non-ideal compressible fluid dynamics, the NICFD Lab of the Propulsion and Power group provides two facilities:

Flexible Asymmetric Shock Tube (FAST)

The FAST is a unique Ludwieg tube-type facility designed and built at the Delft University of Technology. It is made of a 9 m long tube for the experimental exploration of the propagation of rarefaction waves in the dense-vapour of high molecular weight organic fluids.

Research objectives:

  • Investigation of non-ideal gas dynamic effects on the propagation of pressure waves
  • First experimental observation of the theoretically predicted rarefaction shock wave
  • Accurate measurement of the fundamental derivative of gasdynamics


  • 9 m long modular tube
  • Temperature up to 400 °C accurately controlled all along the tube
  • Pressure as high as 20 bar
  • Fast opening valve
  • Two pairs of pressure sensors for wave speed measurement

Organic Vapour Acoustic Resonator

The OVAR is the first-of-its-kind acoustic resonator especially designed to be operated under the extreme conditions found near the critical region of organic fluids. It allows measuring the vapour‑phase speed of sound of various organic fluids.

Research objectives:

  • Testing of existing thermodynamic model
  • Development of new thermodynamic models
  • Direct estimation of the fundamental derivative of gas dynamic in the vapour phase


  • 280 mm long rectangular cavity
  • Low frequency piezoelectric stack excitor
  • Capable of measuring sound speeds ranging between 30 m/s and 300 m/s
  • Maximum temperature of 400 °C
  • Maximum pressure of 10 bar