ID 288

Characterization of ethane jet from sub-critical to super-critical conditions through visible light and X-ray imaging

 

Abstract:

The injection of fuel in a high-pressure gaseous environment, for automotive, aeronautical or rocket applications leads to thermodynamic conditions where pressure exceeds the critical pressure of working fluids and thus, the supercritical state of matter is reached. Providing reliable experimental results under these particular conditions is still nowadays a challenge, but it is of great importance for the validation of numerical codes. Indeed, at such a high pressure, the distinction between gaseous and liquid phases becomes blurred as surface tension decreases and the interface disappears completely. For such special conditions, experimental data are scarce and need to be consolidated. As an example, the modification of the local refractive index induced by density gradient makes the visible-light imaging technique to be used with care. The REFINE test bench (Real-gas Effect on Fluid Injection: a Numerical and Experimental study) has been designed at CORIA Lab to study the non-reactive injection of Ethane and Propane under sub- and supercritical conditions. The ambient gas pressure can be raised up to 6 MPa and warmed up to 573 K to scan sub- and trans-critical injection conditions. The chamber is equipped with two perpendicular accesses allowing different simultaneous diagnostics to be applied to the jet. Experimental data are collected from shadowgraph, diffused backlight illumination techniques and X-Ray. Quantitative measurements of jet spreading angle, breakup length and density maps are compared to literature results.