Design of a fast diaphragmless shock tube driver

Abstract

In this paper, we developed a one-dimensional compressible flow model to study the behavior of various diaphragmless drivers numerically. We determined that the diameter ratio, β d , for the discharge orifice of the back chamber controls driver actuation. Driver performance is optimized by accelerating the barrier element before breaching to minimize the opening time of the driver. Our new two-body driver outperforms various designs and exhibits opening times comparable to those of aluminum burst diaphragms. Experimental results verify the effectiveness of the new driver and show that it closely follows the pressure-Mach curve for the ideal case. Planar laser-induced fluorescence images and pressure traces confirm the consistent formation of shock waves about 41 diameters from the driver.

The effect of initial conditions on mixing transition of the Richtmyer–Meshkov instability

“…All experiments are conducted at the Los Alamos National Laboratory (LANL) Vertical Shock Tube (VST) facility (figure 1a). A diaphragmless plug and sleeve two-piston driver (Mejia-Alvarez et al 2015) is used to produce a Mach 1.2 planar shock wave in a 7 m tall 127 mm × 127 mm square cross-section shock tube. The VST consists of three diagnostic stations (figure 1b).…”

“…A diaphragmless plug and sleeve two-piston driver (Mejia-Alvarez et al. 2015) is used to produce a Mach 1.2 planar shock wave in a 7 m tall square cross-section shock tube. The VST consists of three diagnostic stations (figure 1 b ).…”

The Effect of Geometrical Factors on the Surface Pressure Distribution on a Human Phantom Model Following Shock Exposure: A Computational and Experimental Study

“…The driver section pressure is gradually increased until the point of mechanical failure of the membrane upon which the driver gas is entering the test section, pressurizing the ambient gas and resulting in the formation of the shock wave. Alternative designs employ membraneless drivers where the piston [10][11][12][13], or fast acting valve [14][15][16], are used eliminating the need for membrane replacement between consecutive tests. Both designs have been demonstrated to allow generation of shock waves with diverse magnitudes and characteristics.…”

A concept study for a piston driven sCO2 turbine test facility

“…It is important to note that the instantaneous rupture of a diaphragm in the order of 0.2 milliseconds, contrasting significantly to that of a valve which can take up to 100 times longer to fully open. [21] …”

“…Mejia-Alvarez et al devised a number of analytical correlations for the driver gas and valve opening displacement with respect to time, for a piston valve, a piston with lips valve, and a sleeve valve, which are discussed extensively in [21]. It is important to note that these correlations work under the assumption that the flow is both inviscid, one-dimensional and compressible, and therefore, would be replicable in the L1d3 CFD software utilised and could form the first basis for analysing a potential model of the valve.…”