Shock Wave Properties of Inert and Chemically Active Porous Media

In a recent paper ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’, Malekolkalami and Mohammadi investigate nonlinear electrostatic solitary waves in a plasma comprising adiabatic electrons and positrons, and a stationary ion background. The paper contains two parts: First, the solitary wave properties are discussed through a pseudopotential approach, and then the influence of a small dissipation is intuitively sketched without theoretical underpinning. Small dissipation is claimed to lead to a shock wave whose wavelength is determined by linear oscillator analysis. Unfortunately, there are errors and inconsistencies in both the parts, and their combination is incoherent.

Download Full-text

Shock-wave properties of brittle solids

10.1063/1.50579 ◽

1996 ◽

Cited By ~ 13

Author(s):

D. E. Grady

Keyword(s):

Shock Wave ◽

Brittle Solids ◽

Wave Properties

Download Full-text

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

Journal of Fluid Mechanics ◽

10.1017/jfm.2012.627 ◽

2013 ◽

Vol 718 ◽

pp. 507-523 ◽

Cited By ~ 10

Author(s):

O. Ram ◽

O. Sadot

Keyword(s):

Shock Wave ◽

Porous Medium ◽

Porous Media ◽

Shock Waves ◽

Constitutive Model ◽

Wave Attenuation ◽

Front Face ◽

Viscous Effects ◽

Pressure History ◽

Target Wall

AbstractShock 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.

Download Full-text