Numerical Study of Shock Wave Attenuation in Two-Dimensional Ducts Using Solid Obstacles: How to Utilize Shock Focusing Techniques to Attenuate Shock Waves

Abstract

Research on shock wave mitigation in channels has been a topic of much attention in the shock wave community. One approach to attenuate an incident shock wave is to use obstacles of various geometries arranged in different patterns. This work is inspired by the study from Chaudhuri et al. (2013), in which cylinders, squares and triangles placed in staggered and non-staggered subsequent columns were used to attenuate a planar incident shock wave. Here, we present numerical simulations using a different obstacle pattern. Instead of using a matrix of obstacles, an arrangement of square or cylindrical obstacles placed along a logarithmic spiral curve is investigated, which is motivated by our previous work on shock focusing using logarithmic spirals. Results show that obstacles placed along a logarithmic spiral can delay both the transmitted and the reflected shock wave. For different incident shock Mach numbers, away from the logarithmic spiral design Mach number, this shape is effective to either delay the transmitted or the reflected shock wave. Results also confirm that the degree of attenuation depends on the obstacle shape, effective flow area and obstacle arrangement, much like other obstacle configurations.

Shock Wave Propagation in an Obstructed Area

“…As a result, Skews et al [7] suggested trapping shock wave in a duct with first rows of convergent obstacles followed by rows of divergent obstacles. By confirming the results of Chaudhuri et al [5], Wan et al [8] showed that the obstacles with circular section are not the most efficient to mitigate shock wave. However, obstacles with circular section represent a good approximation of actual environment in urban configuration (poles, trees, traffic lights, humans…).…”

Shock Wave Attenuation Using Foam Obstacles: Does Geometry Matter?

“…The 3D simulation was conducted using Overture, which is an open-source object-oriented code framework to solve partial differential equations using finite differences on composite grids. More information regarding the solver and the method can be found at http://www.overtureframework.org/ or in our previous work [11]. In the simulation, cuboid elements are used to mesh the shock tube.…”

“…A review of the shock wave literature reveals many studies investigating various methods of mitigation. Some methods that have proven effective for this purpose include the introduction of bends inside a duct [1,2], the addition of rigid or semi-rigid structures in the path of the shock wave and baffles, orifices, perforated plates with holes or slits, grids and obstacles of varying geometries placed in different patterns [3][4][5][6][7][8][9][10][11].…”

Numerical investigation of shock wave attenuation in channels using water obstacles

“…Results showed that the staggered matrix of reversed triangular prisms most efficiently attenuated the incident shock wave. More recently, Wan and Eliasson (2015) numerically investigated the shock attenuation ability of a shock focusing geometry. Square and cylindrical rigid obstacles were equidistantly arranged along the edge of a logarithmic spiral, and fixed into a channel.…”