Abstract
The propagation of planar decaying shock and blast waves in non-uniform channels is investigated with the use of a two-equation approximation of the generalized CCW theory. The effects of flow non-uniformity for the cases of an arbitrary strength decaying shock and blast wave in the strong shock limit are considered. Unlike the original CCW theory, the two-equation approximation takes into account the effects of initial temporal flow gradients in the flow properties behind the shock as the shock encounters an area change. A generalized order-of-magnitude analysis is carried out to analyze under which conditions the classical area–Mach (A–M) relation and two-equation approximation are valid given a time constant of decay for the flow properties behind the shock. It is shown that the two-equation approximation extends the applicability of the CCW theory to problems where flow non-uniformity behind the shock is orders of magnitude above that for appropriate use of the A–M relation. The behavior of the two-equation solution is presented for converging and diverging channels and compared against the A–M relation. It is shown that the second-order approximation and A–M relation have good agreement for converging geometries, such that the influence of flow non-uniformity behind the shock is negligible compared to the effects of changing area. Alternatively, the two-equation approximation is shown to be strongly dependent on the initial magnitude of flow non-uniformity in diverging geometries. Further, in diverging geometries, the inclusion of flow non-uniformity yields shock solutions that tend toward an acoustic wave faster than that predicted by the A–M relation.
Similar content being viewed by others
Abbreviations
- a :
-
Sound speed (m/s)
- A :
-
Channel cross-sectional area (m2)
- \(h_0\) :
-
Starting channel height (m)
- M :
-
Mach number
- n :
-
Geometric index
- p :
-
Pressure (N/m2)
- \(Q_1\) :
-
\(\partial p / \partial t + \rho a \partial u / \partial t\) (kg/m s\(^3\))
- \(Q_2\) :
-
\(\partial Q_1/ \partial t\) (kg/m s\(^4\))
- t :
-
Time coordinate (s)
- u :
-
Velocity (m/s)
- W :
-
Shock wave velocity (m/s)
- x :
-
Axial coordinate (m)
- \(\alpha \) :
-
Coefficient function
- \(\beta \) :
-
Coefficient function
- \(\gamma \) :
-
Ratio of specific heats
- \(\theta \) :
-
Channel half-angle
- \(\rho \) :
-
Density (kg/m3)
- \(\tau \) :
-
Time constant of flow property decay (s)
- 0:
-
Initial or undisturbed gas state
- s:
-
Property on the shock
References
Chester, W.: The quasi-cylindrical shock tube. Philos. Mag. 45(371), 1293–1301 (1954). https://doi.org/10.1080/14786441208561138
Chisnell, R.F.: The motion of a shock wave in a channel, with applications to cylindrical and spherical shock waves. J. Fluid Mech. 2(3), 286–298 (1957). https://doi.org/10.1017/S0022112057000130
Whitham, G.B.: On the propagation of shock waves through regions of non-uniform area or flow. J. Fluid Mech. 4(4), 337–360 (1958). https://doi.org/10.1017/S0022112058000495
Russell, D.A.: Shock-wave strengthening by area convergence. J. Fluid Mech. 27(2), 305–314 (1967). https://doi.org/10.1017/S0022112067000333
Setchell, R.E., Storm, E., Sturtevant, B.: An investigation of shock strengthening in a conical convergent channel. J. Fluid Mech. 56(3), 505–522 (1972). https://doi.org/10.1017/S0022112072002484
Nettleton, M.A.: Shock attenuation in a ‘gradual’ area expansion. J. Fluid Mech. 60(2), 209–5223 (1973). https://doi.org/10.1017/S0022112073000121
Igra, O., Elperin, T., Falcovitz, J., Zmiri, B.: Shock wave interaction with area changes in ducts. Shock Waves 3(3), 233–238 (1994). https://doi.org/10.1007/BF01414717
Whitham, G.B.: A new approach to problems of shock dynamics. Part I. Two dimensional problems. J. Fluid Mech. 2(2), 145–171 (1957). https://doi.org/10.1017/S002211205700004X
Ridoux, J., Lardjane, N., Monasse, L., Coulouvrat, F.: Comparison of geometrical shock dynamics and kinematic models for shock-wave propagation. Shock Waves 28(2), 401–416 (2017). https://doi.org/10.1007/s00193-017-0748-2
Best, J.P.: A generalization of the theory of geometrical shock dynamics. Shock Waves 1(4), 251–273 (1991). https://doi.org/10.1007/BF01418882
Kirkwood J.G., Bethe H.A.: The pressure wave produced by an underwater explosion. Office of Scientific Research and Development Report No. 588 (1942)
Sharma, V.D., Ram, R., Sachdev, P.L.: Uniformly valid analytical solution to the problem of a decaying shock wave. J. Fluid Mech. 185, 153–170 (1987). https://doi.org/10.1017/S0022112087003124
Sedov, L.I.: Similarity and Dimensional Methods in Mechanics, Chapter IV, “One-Dimensional Unsteady Motion of a Gas”. Academic Press, New York (1959). https://doi.org/10.1016/B978-1-4832-0088-0.50011-6
Bethe, H.A., Fuchs, K., Hirschfelder, J.O., Magee, J.L., Peierls, R.E., von Neumann, J.: Blast waves. Los Alamos Scientific Laboratory Report LA-2000 (1947)
Taylor, G.I.: The formation of a blast wave by a very intense explosion. Proc. R. Soc. Lond. A 201, 159–174 (1950). https://doi.org/10.1098/rspa.1950.0049
Han, Z., Yin, X.: Shock Dynamics, Chapter 1, “Relation Between M and A for a Uniform Quiescent Gas Ahead of a Shock Wave”. Kluwer, Beijing (1993). https://doi.org/10.1007/978-94-017-2995-6_2
Kamm J.R.: Evaluation of the Sedov–von Newman–Taylor blast wave solution. Los Alamos Scientific Laboratory Report LA-UR-00-6055 (2000)
Takayama, K., Kleine, H., Grönig, H.: An experimental investigation of the stability of converging cylindrical shock waves in air. Exp. Fluids 5(5), 315–322 (1987). https://doi.org/10.1007/BF00277710
Zha, Z., Si, T., Luo, X., Yang, J., Liu, C., Tan, D., Zou, L.: Parametric study of cylindrical converging shock waves generated based on shock dynamics theory. Phys. Fluids 24, 026101 (2012). https://doi.org/10.1063/1.3682376
Liverts, M., Apazidis, N.: Limiting temperatures of spherical shock wave implosion. Phys. Rev. 116, 014501 (2016). https://doi.org/10.1103/PhysRevLett.116.014501
Friedlander, F.G.: The diffraction of sound pulses I. Diffraction by a semi-infinite plane. Proc. R. Soc. A 186(1006), 322–343 (1946). https://doi.org/10.1098/rspa.1946.0046
Milton, B.E.: Mach reflection using ray-shock theory. AIAA J. 13(11), 1531–1533 (1975). https://doi.org/10.2514/3.60566
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by D. Zeitoun and A. Higgins.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
An abridged version of this paper was presented at the 22nd International Shock Interaction Symposium, July 4–8, 2016, Glasgow, UK.
Rights and permissions
About this article
Cite this article
Peace, J.T., Lu, F.K. On the propagation of decaying planar shock and blast waves through non-uniform channels. Shock Waves 28, 1223–1237 (2018). https://doi.org/10.1007/s00193-018-0818-0
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00193-018-0818-0