Gas-ionizing shock and combustion waves in magnetogasdynamics

1962 ◽  
Vol 14 (3) ◽  
pp. 405-419 ◽  
Author(s):  
J. B. Helliwell
Keyword(s):  
Shock Wave ◽  
Electromagnetic Field ◽  
Shock Waves ◽  
Combustion Wave ◽  
Density Ratio ◽  
Combustion Waves ◽  
One Dimensional ◽  
Inviscid Gas ◽  
Density Ratios ◽  
Hugoniot Curves

Some general properties of one-dimensional deflagration waves in a non-conducting inviscid gas at rest are discussed when ionization of the gas takes place across a shock wave which precedes the flame front, and electromagnetic fields are present. The direction of wave propagation, the electric field and magnetic field are taken as a mutually orthogonal triad of vectors. The jump relationships across the gas-ionizing shock wave and magnetogasdynamic combustion wave are investigated and the two Hugoniot curves analysed in detail in the pressure-specific volume plane. The possible types of wave are indicated for arbitrary magnitudes of the upstream electromagnetic field. It is shown that weak gasionizing shock waves cannot exist. For suitably chosen electromagnetic field strenghts the density ratio across the shock wave may be greater than the ordinary gasdynamic limit and, in such cases, the pressure and density ratios are related in an inverse manner, in contrast to the behaviour for ordinary gasdynamic or magnetogasdynamic shock waves. The magnetogasdynamic combustion wave has similar properties to that in ordinary gasdynamics.

Analysis of Normal Combustion Waves in CH4-Air System

2014 ◽  
Vol 656 ◽  
pp. 101-109 ◽  
Author(s):  
Daniel Eugeniu Crunteanu ◽  
Dan Racoti ◽  
Corneliu Berbente
Keyword(s):  
Shock Waves ◽  
Algebraic Equation ◽  
Combustion Wave ◽  
Normal Shock ◽  
Combustion Waves ◽  
Conservation Equations ◽  
One Dimensional ◽  
Air System ◽  
The One

In this study one analyses the detonation and deflagration waves starting with Euler one-dimensional conservative equations. We present two methods of computing the normal combustion waves and normal shock waves parameters. The second one, called Cpm method, uses the one dimensional conservation equations system of mass, impulse and energy reduced to an quadratic algebraic equation. Combustion wave ,in CH4-air system is presented as an application.

Thermodynamics and one dimensional shock waves in materials with memory

1966 ◽  
Vol 292 (1431) ◽  
pp. 562-574 ◽  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Long Range ◽  
Materials With Memory ◽  
One Dimensional ◽  
Small Intensity ◽  
Linear Viscoelastic ◽  
Hugoniot Curves ◽  
With Memory ◽  
Arbitrary Intensity

We consider one dimensional shock waves in materials which do not conduct heat. We show that most of the classical theory of Hugoniot curves can be broadly generalized to substances having long range, non-linear, viscoelastic memory. For example, the presence of memory does not destroy the conclusion that the jump in entropy across a shock wave of small intensity is of order three or higher in the jump in the strain. The theorems of Bethe and Weyl on shocks of arbitrary intensity also can be generalized to materials with memory.

Magnetogasdynamic deflagration and detonation waves with ionization

1963 ◽  
Vol 16 (2) ◽  
pp. 243-261 ◽  
Author(s):  
J. B. Helliwell
Keyword(s):  
Shock Wave ◽  
Electromagnetic Field ◽  
Combustion Wave ◽  
Detonation Waves ◽  
Ionized Gas ◽  
One Dimensional ◽  
Jouguet Point ◽  
Electric And Magnetic Fields ◽  
The Waves ◽  
Steady Detonation

The propagation of a one-dimensional combustion wave into a non-ionized gas at rest in the presence of an electromagnetic field is considered when ionization of the gas occurs across either the combustion wave or a preceding shock wave. The electric and magnetic fields in the undisturbed gas ahead of the waves are mutually perpendicular and orthogonal to the direction of wave propagation. It is shown that steady detonation occurs at a point which is analogous to the Chapman-Jouguet point of ordinary gasdynamic combustion theory. Numerical calculations are made of the state of the gas between and behind the waves in two particlar models, in both of which the upstream electric field is zero. The models are then equivalent to magnetogasdynamic phenomena in a perfectly conducting gas. First, the case of steady detonation is studied. Secondly, steady deflagration in a tube, closed at one end, is discussed.

Shock Wave - Film Cooling Interactions in Transonic Flows

2001 ◽  
Author(s):  
P. M. Ligrani ◽  
C. Saumweber ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Shock Waves ◽  
Film Cooling ◽  
Cross Flow ◽  
Injection Velocity ◽  
Film Cooling Effectiveness ◽  
Mach Numbers ◽  
Density Ratios ◽  
Film Cooling Holes

Interactions between shock waves and film cooling are described as they affect magnitudes of local and spanwise-averaged adiabatic film cooling effectiveness distributions. A row of three cylindrical holes is employed. Spanwise spacing of holes is 4 diameters, and inclination angle is 30 degrees. Freestream Mach numbers of 0.8 and 1.10–1.12 are used, with coolant to freestream density ratios of 1.5–1.6. Shadowgraph images show different shock structures as the blowing ratio is changed, and as the condition employed for injection of film into the cooling holes is altered. Investigated are film plenum conditions, as well as perpendicular film injection cross-flow Mach numbers of 0.15, 0.3, and 0.6. Dramatic changes to local and spanwise-averaged adiabatic film effectiveness distributions are then observed as different shock wave structures develop in the immediate vicinity of the film-cooling holes. Variations are especially evident as the data obtained with a supersonic Mach number are compared to the data obtained with a freestream Mach number of 0.8. Local and spanwise-averaged effectiveness magnitudes are generally higher when shock waves are present when a film plenum condition (with zero cross-flow Mach number) is utilized. Effectiveness values measured with a supersonic approaching freestream and shock waves then decrease as the injection cross-flow Mach number increases. Such changes are due to altered flow separation regions in film holes, different injection velocity distributions at hole exits, and alterations of static pressures at film hole exits produced by different types of shock wave events.

Rankine–Hugoniot-Berechnungen für Nichtgleichgewichts-Plasmen

1966 ◽  
Vol 21 (11) ◽  
pp. 1960-1963
Author(s):  
J. Artmann
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Pressure Ratio ◽  
Density Ratio ◽  
Charged Particles ◽  
Strong Shock ◽  
Ion Temperature ◽  
Saha Equation ◽  
Wave Parameters ◽  
Strong Shock Waves

In optically thin plasmas produced by strong shock waves the SAHA equation is no longer valid to describe the conditions directly behind the shock wave. Photoionisation may be neglected in the balance of production and recombination of charged particles. For the case of nonequilibrium a calculation assuming various ratios of electron to ion temperature (ϑ= TeT) shows that the shock wave parameters are described sufficiently well by the Korona-equation. Temperature, density ratio and electron density are increased with increasing ϑ whereas the pressure ratio is independent of the kind of equilibrium and ϑ.

scholarly journals Normal Reflection Characteristics of One-Dimensional Unsteady Flow Shock Waves on Rigid Walls from Pulse Discharge in Water

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Dong Yan ◽  
Jinchang Zhao ◽  
Shaoqing Niu
Keyword(s):  
Shock Wave ◽  
Hydrostatic Pressure ◽  
Shock Waves ◽  
Pulse Discharge ◽  
Weak Shock ◽  
Rigid Wall ◽  
Wave Source ◽  
One Dimensional ◽  
Normal Reflection ◽  
Rigid Walls

Strong shock waves can be generated by pulse discharge in water, and the characteristics due to the shock wave normal reflection from rigid walls have important significance to many fields, such as industrial production and defense construction. This paper investigates the effects of hydrostatic pressures and perturbation of wave source (i.e., charging voltage) on normal reflection of one-dimensional unsteady flow shock waves. Basic properties of the incidence and reflection waves were analyzed theoretically and experimentally to identify the reflection mechanisms and hence the influencing factors and characteristics. The results indicated that increased perturbation (i.e., charging voltage) leads to increased peak pressure and velocity of the reflected shock wave, whereas increased hydrostatic pressure obviously inhibited superposition of the reflection waves close to the rigid wall. The perturbation of wave source influence on the reflected wave was much lower than that on the incident wave, while the hydrostatic pressure obviously affected both incident and reflection waves. The reflection wave from the rigid wall in water exhibited the characteristics of a weak shock wave, and with increased hydrostatic pressure, these weak shock wave characteristics became more obvious.

scholarly journals Approaching the “cold curve” in laser-driven shock wave experiment of a matter precompressed by a partially perforated diamond anvil

2012 ◽  
Vol 31 (1) ◽  
pp. 73-79 ◽  
Author(s):  
N. Nissim ◽  
S. Eliezer ◽  
M. Werdiger ◽  
L. Perelmutter
Keyword(s):  
Shock Wave ◽  
Diamond Anvil Cell ◽  
Compression Curve ◽  
One Dimensional ◽  
Cold Compression ◽  
Relative Contribution ◽  
Order Of Magnitude ◽  
Diamond Anvil ◽  
Hugoniot Curves ◽  
Shock Wave Experiment

AbstractThis paper suggests a novel route to approach the cold compression curve in laser-plasma induced shock waves. This effect is achieved with a precompression in a diamond anvil cell (DAC). In order to keep the necessary structure of one dimensional shock wave it is required to use a diamond anvil cell with a partially perforated diamond anvil. Precompression pressures of about 50 GPa, that are an order of magnitude higher than the currently reported pressures, are possible to obtain with presentley existing diamond anvil cell technology. The precompressed Hugoniot of Al was calculated for different precompression pressures and it was found that at precompression pressure of 50 GPa the Hugoniot follows the “cold curve” up to about 2 Mbar and 5.2 g/cc. Furthermore, the thermal relative contribution on the Hugoniot curves is calculated.

Precursor shock waves at a slow—fast gas interface

1976 ◽  
Vol 76 (1) ◽  
pp. 157-176 ◽  
Author(s):  
A. M. Abd–El–Fattah ◽  
L. F. Henderson ◽  
A. Lozzi
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Shock Wave ◽  
Shock Waves ◽  
Plane Shock ◽  
One Dimensional ◽  
Irregular Wave ◽  
Irregular Systems ◽  
Theory And Experiment ◽  
Good Agreement

This paper presents experimental data obtained for the refraction of a plane shock wave at a carbon dioxide–helium interface. The gases were separated initially by a delicate polymer membrane. Both regular and irregular wave systems were studied, and a feature of the latter system was the appearance of bound and free precursor shocks. Agreement between theory and experiment is good for regular systems, but for irregular ones it is sometimes necessary to take into account the effect of the membrane inertia to obtain good agreement. The basis for the analysis of irregular systems is one-dimensional piston theory and Snell's law.

One-dimensional spherical shock waves in an interstellar dusty gas clouds

2021 ◽  
Vol 76 (5) ◽  
pp. 417-425
Author(s):  
Astha Chauhan ◽  
Kajal Sharma
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Differential Equations ◽  
Shock Propagation ◽  
Dusty Gas ◽  
Shock Strength ◽  
Efficient System ◽  
One Dimensional ◽  
Arbitrary Strength ◽  
Spherical Shock

Abstract A system of partial differential equations describing the one-dimensional motion of an inviscid self-gravitating and spherical symmetric dusty gas cloud, is considered. Using the method of the kinematics of one-dimensional motion of shock waves, the evolution equation for the spherical shock wave of arbitrary strength in interstellar dusty gas clouds is derived. By applying first order truncation approximation procedure, an efficient system of ordinary differential equations describing shock propagation, which can be regarded as a good approximation of infinite hierarchy of the system. The truncated equations, which describe the shock strength and the induced discontinuity, are used to analyze the behavior of the shock wave of arbitrary strength in a medium of dusty gas. The results are obtained for the exponents from the successive approximation and compared with the results obtained by Guderley’s exact similarity solution and characteristic rule (CCW approximation). The effects of the parameters of the dusty gas and cooling-heating function on the shock strength are depicted graphically.

scholarly journals Modern infinitesimals and the entropy jump across an inviscid shock wave

2018 ◽  
Vol 17 (4-5) ◽  
pp. 502-520
Author(s):  
Roy S Baty ◽  
Len G Margolin
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Euler Equations ◽  
Nonstandard Analysis ◽  
Generalized Solutions ◽  
Perfect Gas ◽  
One Dimensional ◽  
Number Systems ◽  
Shock Thickness ◽  
Modern Mathematics

This article applies nonstandard analysis to study the generalized solutions of entropy and energy across one-dimensional shock waves in a compressible, inviscid, perfect gas. Nonstandard analysis is an area of modern mathematics that studies number systems that contain both infinitely large and infinitely small numbers. For an inviscid shock wave, it is assumed that the shock thickness occurs on an infinitesimal interval and that the jump functions for the field variables are smoothly defined on this interval. A weak converse to the existence of the entropy peak is derived and discussed. Generalized solutions of the Euler equations for entropy and energy are then derived for both theoretical and realistic normalized velocity profiles.

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