Head-on collision of normal shock waves with rigid porous materials

Levy, Avi; Ben‐Dor, G.; Skews, B. W.; Sorek, S.

doi:10.1007/bf00189885

Cited by 59 publications

(45 citation statements)

References 14 publications

(8 reference statements)

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“…Instead, a filtration process during which the pressure on the wall increases gradually takes place (Seitz & Skews 1996;Britan et al 2001Kitagawa et al 2006;Britan, Shapiro & Ben-Dor 2007). This filtration effect is well documented for rigid porous media, in which the porous skeleton remained rigid when impinged by a shock wave (Levy et al 1993;Levy, Ben-Dor & Sorek 1996a, 1998Andreopoulos, Xanthos & Subramaniam 2007;Kazemi-Kamyab, Subramaniam & Andreopoulos 2011). In their investigations rigid porous samples were placed either adjacent to the supporting wall or with a predetermined gap, i.e.…”

Section: Introductionmentioning

confidence: 97%

A simple constitutive model for predicting the pressure histories developed behind rigid porous media impinged by shock waves

Ram

Sadot

2013

J. Fluid Mech.

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Shock wave attenuation by means of rigid porous media is often applied when protective structures are dealt with. The passage of a shock wave through a layer of porous medium is accompanied by diffractions and viscous effects that attenuate and weaken the transmitted shock, thus reducing the load that develops on the target wall that is placed behind the protective layer. In the present study, the parameters governing the pressure build-up on the target wall are experimentally investigated using a shock tube facility. Different porous samples are impinged by normal shock waves of various strengths and the subsequent pressure histories that are developed on the target wall are recorded. In addition, different standoff distances from the target wall are investigated. Assuming that the flow through the porous medium is close to being isentropic enabled us to develop a general constitutive model for predicting the pressure history developed on the target wall. This model can be applied to predict the pressure build-up on the target wall for any pressure history that is imposed on the front face of the porous sample without the need to conduct numerous experiments. Results obtained by other investigators are found to be in very good agreement with the predictions of the presently developed constitutive model.

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Section: Introductionmentioning

confidence: 97%

A simple constitutive model for predicting the pressure histories developed behind rigid porous media impinged by shock waves

Ram

Sadot

2013

J. Fluid Mech.

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“…Numerical simulations with the one-dimensional version of this model (Levy et al, 1996) proved to yield excellent agreement with experimental observations, concerning almost nondeformable porous materials. The results of the experimental study of Levy et al (1993) with 40 mm long sample made of SiC having 10 pores per inch and an incident-shock-wave Mach number of 1.378, for the pressure histories of air at various locations along the shock tube, are presented in Figure 1. In Levi-Hevroni et al (2002), following Levy et al (1995), we consider a solid matrix that is capable to undergo extremely large deformations.…”

Section: Shock Waves Through a Highly Deformable Porous Mediummentioning

confidence: 99%

“…To verify the performance of this approach, simulations were compared against the shock tube experiments of Levy et al (1993) and the onedimensional simulations (Levy et al, 1996) of a porous matrix undergoing small deformations. The gas pressure histories upstream of the porous material, on the side-wall inside the porous material and at the end-wall are shown in Figure 1(a)-(c), respectively.…”

Section: Shock Waves Through a Highly Deformable Porous Mediummentioning

confidence: 99%

Extensions to the Macroscopic Navier–Stokes Equation

Sorek

Levi-Hevroni²,

Levy³

et al. 2005

Transp Porous Med

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A development is provided showing that for any phase, by not neglecting the macroscopic terms of the deviation from the intensive momentum and of the dispersive momentum, we obtain a macroscopic secondary momentum balance equation coupled with a macroscopic dominant momentum balance equation that is valid at a larger spatial scale. The macroscopic secondary momentum balance equation is in the form of a wave equation that propagates the deviation from the intensive momentum while concurrently, in the case of a Newtonian fluid and under certain assumptions, the macroscopic dominant momentum balance equation may be approximated by Darcy's equation to address drag dominant flow. We then develop extensions to the dominant macroscopic NavierStokes (NS) equation for saturated porous matrices, to account for the pressure gradient at the microscopic solid-fluid interfaces. At the microscopic interfaces we introduce the exchange of inertia between the phases, accounting for the relative fluid square velocities and the rate of these velocities, interpreted as Forchheimer terms. Conditions are provided to approximate the extended dominant NS equation by Forchheimer quadratic momentum law or by Darcy's linear momentum law. We also show that the dominant NS equation can conform into a nonlinear wave equation. The one-dimensional numerical solution of this nonlinear wave equation demonstrates good qualitative agreement with experiments for the case of a highly deformable elasto-plastic matrix.

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“…standoff distance (SOD), between the rear face of the porous sample and the shock tube end wall. The investigations revealed that the pressure that was developed on the end wall was affected by the shock wave strength, the fluid properties, the porous sample properties and the standoff distance, which determines the volume of the abovementioned air gap (Levy et al 1993 In more recent research, Kazemi-Kamyab et al (2011) studied experimentally the stress transmitted to the end wall of a shock tube shielded by a rigid porous medium. They showed that the introduction of a fixed air gap between the porous sample and the end wall decreased the stress transmitted to the end wall.…”

mentioning

confidence: 99%

“…Shock interaction with a rigid porous medium Skews, Atkins & Seitz (1992), Levy et al (1993), Levy, Ben-Dor & Sorek (1996, 1998, Andreopoulos, Xanthos & Subramaniam (2007) and Kazemi-Kamyab et al (2011) have conducted several studies on the interaction of shock waves with rigid porous media in which the skeleton of the porous medium remained incompressible when impinged by the shock waves. In these studies, the filtration effect was well documented to be the governing mechanism affecting the shock wave passage through the porous medium and the development of the flow field inside and in the vicinity of the porous medium.…”

mentioning

confidence: 99%

Analysis of the pressure buildup behind rigid porous media impinged by shock waves in time and frequency domains

Ram

Sadot

2015

J. Fluid Mech.

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The transformation of a time-dependent pressure pulse imposed on the front face of a rigid porous medium sample, mounted in a tunnel, through the sample and a fixed-volume air gap between the rear face of the sample and the end wall of a tunnel is studied both experimentally and analytically. In the experiments, rigid porous samples that are placed at various distances from a shock tube end wall are subjected to the impingement of shock waves. The pressure buildup behind the porous sample is monitored and compared with the pressure imposed at the front face of the porous sample. The shock tube is fitted with a short driver section in order to generate blast-like decaying pressure profiles, which continue to decay after the initial shock impingement. In this scenario, the measured pressure profile at the end wall, which is affected by the properties of the porous medium and the size of the air gap separating its rear face and the shock tube end wall, is significantly different from the pressure profile imposed on the front face of the porous sample. The mechanism governing the pressure transformation provided by the porous medium is attributed to a selective filtration process that attenuates the pressure changes associated with high frequencies. The results of the present study are also analysed in conjunction with previously published analytical and numerical models to achieve a broader understanding of the physical mechanisms affecting the pressure buildup.

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Head-on collision of normal shock waves with rigid porous materials

Cited by 59 publications

References 14 publications

A simple constitutive model for predicting the pressure histories developed behind rigid porous media impinged by shock waves

A simple constitutive model for predicting the pressure histories developed behind rigid porous media impinged by shock waves

Extensions to the Macroscopic Navier–Stokes Equation

Analysis of the pressure buildup behind rigid porous media impinged by shock waves in time and frequency domains

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