Interaction of Liquid Droplets With Planar Shock Waves

1990 ◽  
Vol 112 (4) ◽  
pp. 481-486 ◽  
Author(s):  
T. Yoshida ◽  
K. Takayama
Keyword(s):  
Mach Number ◽  
Shock Waves ◽  
Reynolds Numbers ◽  
Liquid Droplets ◽  
Double Exposure ◽  
Cross Sectional ◽  
Planar Shock ◽  
Shock Mach Number ◽  
Holographic Interferogram ◽  
Double Exposure Holographic Interferometry

Interactions and breakup processes of 1.50-mm-diameter ethyl alcohol droplets and 5.14-mm-diameter water bubbles with planar shock waves were observed using double-exposure holographic interferometry. Experiments were conducted in a 60 mm × 150 mm cross-sectional shock tube for shock Mach number 1.56 in air. The Weber numbers of droplets and liquid bubbles were 5.6 × 103 and 2.9 × 103, respectively, while the corresonding Reynolds numbers were 4.2 × 10 and 1.5 × 105. It is shown that the resulting holographic interferogram can eliminate the effect of the mists produced by the breakup of the droplets and clearly show the structure of a disintegrating droplet and its wake. This observation was impossible by conventional optical flow visualization. It is demonstrated that the time variation of the diameter of a breaking droplet measured by conventional optical techniques has been overestimated by up to 35 percent.

Equilibrium Thermodynamic Properties Behind Strong Shocks in Helium

1968 ◽  
Vol 72 (686) ◽  
pp. 155-159
Author(s):  
M. Lalor ◽  
H. Daneshyar
Keyword(s):  
Mach Number ◽  
Partition Function ◽  
Shock Waves ◽  
Thermodynamic Properties ◽  
Strong Shock ◽  
Equilibrium Thermodynamic ◽  
Ionized Gas ◽  
Number Range ◽  
Shock Mach Number ◽  
Strong Shock Waves

Summary Tables of equilibrium thermodynamic properties of the ionized gas formed behind strong shock waves in Helium are presented, in the Mach number range 10 to 30, for initial pressures of 0-1, 0-5, 1, 5, 10, 50, 100 torr. The effect of the inclusion of the full partition function series is demonstrated in the Mach number range 20 to 30. A numerical solution has been developed such that the only experimental quantities required for its use are the shock Mach number and the pre-shock conditions.

scholarly journals Exploring the role of cosmological shock waves in the Dianoga simulations of galaxy clusters

2021 ◽  
Author(s):  
S Planelles ◽  
S Borgani ◽  
V Quilis ◽  
G Murante ◽  
V Biffi ◽  
...  
Keyword(s):  
Mach Number ◽  
Shock Waves ◽  
Galaxy Clusters ◽  
Cluster Mass ◽  
Mach Number Distribution ◽  
Disturbed Systems ◽  
Shock Mach Number ◽  
Formation And Evolution ◽  
Massive Clusters

Abstract Cosmological shock waves are ubiquitous to cosmic structure formation and evolution. As a consequence, they play a major role in the energy distribution and thermalization of the intergalactic medium (IGM). We analyse the Mach number distribution in the Dianoga simulations of galaxy clusters performed with the SPH code GADGET-3. The simulations include the effects of radiative cooling, star formation, metal enrichment, supernova and active galactic nuclei feedback. A grid-based shock-finding algorithm is applied in post-processing to the outputs of the simulations. This procedure allows us to explore in detail the distribution of shocked cells and their strengths as a function of cluster mass, redshift and baryonic physics. We also pay special attention to the connection between shock waves and the cool-core/non-cool core (CC/NCC) state and the global dynamical status of the simulated clusters. In terms of general shock statistics, we obtain a broad agreement with previous works, with weak (low-Mach number) shocks filling most of the volume and processing most of the total thermal energy flux. As a function of cluster mass, we find that massive clusters seem more efficient in thermalising the IGM and tend to show larger external accretion shocks than less massive systems. We do not find any relevant difference between CC and NCC clusters. However, we find a mild dependence of the radial distribution of the shock Mach number on the cluster dynamical state, with disturbed systems showing stronger shocks than regular ones throughout the cluster volume.

Further results on the over-all density ratios of shock waves in carbon dioxide

1963 ◽  
Vol 17 (2) ◽  
pp. 267-270 ◽  
Author(s):  
H. K. Zienkiewicz ◽  
N. H. Johannesen ◽  
J. H. Gerrard
Keyword(s):  
Carbon Dioxide ◽  
Mach Number ◽  
Shock Waves ◽  
Density Ratio ◽  
Shock Mach Number ◽  
Density Ratios

Previous results on the over-all density ratio of shock waves in CO2, confirming experimentally the theoretical equilibrium value, have been extended to a shock Mach number of 7·3. The discrepancy between our results and earlier Princeton results approaches 18% at a Mach number of 7. Possible reasons for this are discussed, with particular reference to the interferometer technique, but no explanation has been found.

scholarly journals Non-ideal oblique shock waves

2018 ◽  
Vol 847 ◽  
pp. 266-285 ◽  
Author(s):  
Davide Vimercati ◽  
Giulio Gori ◽  
Alberto Guardone
Keyword(s):  
Mach Number ◽  
Shock Waves ◽  
Finite Amplitude ◽  
Oblique Shock ◽  
Saturation Curve ◽  
Close Proximity ◽  
Post Shock ◽  
Shock Mach Number ◽  
Molecular Complexity ◽  
Oblique Shocks

From the analysis of the isentropic limit of weak compression shock waves, oblique shock waves in which the post-shock Mach number is larger than the pre-shock Mach number, named non-ideal oblique shocks, are admissible in substances characterized by moderate molecular complexity and in the close proximity to the liquid–vapour saturation curve. Non-ideal oblique shocks of finite amplitude are systematically analysed, clarifying the roles of the pre-shock thermodynamic state and Mach number. The necessary conditions for the occurrence of non-ideal oblique shocks of finite amplitude are singled out. In the parameter space of pre-shock thermodynamic states and Mach number, a new domain is defined which embeds the pre-shock states for which the Mach number increase can possibly take place. The present findings are confirmed by state-of-the-art thermodynamic models applied to selected commercially available fluids, including siloxanes and hydrocarbons currently used as working fluids in renewable energy systems.

Experimental Investigation of Two Cylindrical Water Columns Subjected to Planar Shock Wave Loading

2003 ◽  
Vol 125 (2) ◽  
pp. 325-331 ◽  
Author(s):  
D. Igra ◽  
K. Takayama
Keyword(s):  
Shock Wave ◽  
Drag Coefficient ◽  
Water Column ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Planar Shock ◽  
Water Columns ◽  
Planar Shock Wave ◽  
Shock Tube Test ◽  
Double Exposure Holographic Interferometry

Two water columns with identical initial diameters of 4.8 mm were placed 30 mm apart inside a shock tube test section and were loaded by a shock wave of Mach number 1.47 in atmospheric air. The Weber and Reynolds numbers corresponding to these flow conditions are 6900 and 112,000, respectively. Double-exposure holographic interferometry was used to visualize the shock/water columns interaction. The process of the water columns deformation, displacement, and acceleration was well visualized and hence the drag coefficient of shock loaded water columns was evaluated. The front water column behaved virtually the same as a single water column under the same flow conditions. However, the displacement and acceleration of the rear water column was less significant than that of the front one. Hence, its drag coefficient is less. These results show that the front water column has affected the flow field around the rear water column.

Study of Two Cylindrical Water Columns Subjected to Planar Shock Wave Loading

2000 ◽  
Author(s):  
D. Igra ◽  
K. Takayama
Keyword(s):  
Shock Wave ◽  
Drag Coefficient ◽  
Water Column ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Planar Shock ◽  
Water Columns ◽  
Planar Shock Wave ◽  
Shock Tube Test ◽  
Double Exposure Holographic Interferometry

Abstract Two water columns with identical initial diameters of 4.8 mm were placed 30 mm apart inside a shock tube test section and loaded by a shock wave of Mach number 1.47 in atmospheric air. The Weber and Reynolds numbers corresponding to these flow conditions are 6,900 and 112,000, respectively. Double exposure holographic interferometry was used to visualize the shock/water columns interaction. The process of the water columns deformation, displacement, acceleration was well visualized and hence the drag coefficient of shock loaded water columns was evaluated. The water column in the front behaved virtually the same as a single water column. However the displacement and acceleration of the rear water column was less significant than that of the front one. Hence its drag coefficient is less. These results show that the frontal water column has affected the flow field around the rear water column.

Plane shock waves and Haff’s law in a granular gas

2015 ◽  
Vol 779 ◽  
Author(s):  
M. H. Lakshminarayana Reddy ◽  
Meheboob Alam
Keyword(s):  
Mach Number ◽  
Shock Waves ◽  
Energy Equation ◽  
Navier Stokes ◽  
Maximum Temperature ◽  
Plane Shock ◽  
Density Peak ◽  
Granular Gas ◽  
Planar Shock ◽  
Weak Shocks

The Riemann problem of planar shock waves is analysed for a dilute granular gas by solving Euler- and Navier–Stokes-order equations numerically. The density and temperature profiles are found to be asymmetric, with the maxima of both density and temperature occurring within the shock layer. The density peak increases with increasing Mach number and inelasticity, and is found to propagate at a steady speed at late times. The granular temperature at the upstream end of the shock decays according to Haff’s law (${\it\theta}(t)\sim t^{-2}$), but the downstream temperature decays faster than its upstream counterpart. Haff’s law seems to hold inside the shock up to a certain time for weak shocks, but deviations occur for strong shocks. The time at which the maximum temperature deviates from Haff’s law follows a power-law scaling with the upstream Mach number and the restitution coefficient. The origin of the continual build-up of density with time is discussed, and it is shown that the granular energy equation must be ‘regularized’ to arrest the maximum density.

scholarly journals Study on Mach stems induced by interaction of planar shock waves on two intersecting wedges

2015 ◽  
Vol 32 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Gaoxiang Xiang ◽  
Chun Wang ◽  
Honghui Teng ◽  
Yang Yang ◽  
Zonglin Jiang
Keyword(s):  
Shock Waves ◽  
Planar Shock
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