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.

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.

scholarly journals Mathematical modeling and numerical investigation of density wave instability of supercritical natural circulation loop

2021 ◽  
Vol 321 ◽  
pp. 04004
Author(s):  
Santosh Kumar Rai ◽  
Neha Ahlawat ◽  
Pardeep Kumar ◽  
Vinay Panwar
Keyword(s):  
Energy Conservation ◽  
Natural Circulation ◽  
Density Wave ◽  
Circulation Loop ◽  
Wave Instability ◽  
Conservation Equations ◽  
One Dimensional ◽  
Natural Circulation Loop ◽  
The One ◽  
Riser Height

In present paper, a mathematical model based on the one dimensional nonlinear mass, momentum and energy conservation equations has been developed to study the density wave instability (DWI) in horizontal heater and horizontal cooler supercritical water natural circulation loop (HHHC-SCWNCL). The one dimensional nonlinear mass, momentum and energy conservation equations are discretized by using finite difference method (FDM). The numerical model is validated with the benchmark results (NOLSTA model). Numerical simulations are performed to find the threshold stability zone (TSZ) and draw the stability map for natural circulation loop. Further, effect of change in diameter and riser height on the density wave instability of SCWNCL has been investigated.

Probing of Flow Fields with Shock Waves—The Swing Probe

1971 ◽  
Vol 49 (10) ◽  
pp. 1340-1349 ◽  
Author(s):  
J. D. Strachan ◽  
B. Ahlborn
Keyword(s):  
Shock Waves ◽  
Source Term ◽  
Flow Fields ◽  
Inhomogeneous Media ◽  
Shock Propagation ◽  
Local Velocity ◽  
One Dimensional ◽  
Density Distributions ◽  
The One ◽  
Velocity Pressure

The one dimensional equations governing shock propagation into inhomogeneous media have been developed to allow a shock to be used as a probe. Shock waves which collide with unknown gas or plasma flow fields suffer a change in velocity. Pressure, density, particle velocity, and local energy input at the edge of an unknown flow can be determined from the measurement of unknown flow. The steady variation of the velocity of strong probing shocks reveals details of the local velocity and density distributions inside the unknown flow field. One further result is the extension of the general theory of shock propagation into inhomogeneous media to cover the case when an energy source term appears at the front.

Diesel Electro-injector: A Numerical Simulation Code

1995 ◽  
Vol 117 (4) ◽  
pp. 792-798 ◽  
Author(s):  
P. Digesu ◽  
D. Laforgia
Keyword(s):  
Flow Rate ◽  
Parametric Analysis ◽  
Magnetic Force ◽  
Simulation Code ◽  
Conservation Equations ◽  
One Dimensional ◽  
Element Simulation ◽  
System Energy ◽  
The One ◽  
Volume Method

A simulation code of an electro-injector for diesel engines is presented with the preliminary parametric analysis carried out with the code. The simulation code is based upon the concentrated volume method as for the chambers of the system. Energy and flow rate conservation equations and dynamic equations are used for the movable parts of the system under stress or friction. The magnetic force acting on the electro-injector actuator has been calculated by means of a finite element simulation. The one-dimensional code simulated the propagation in feeding pipes and the control of the electro-injector. The program, in fact, uses the method of the characteristic equations to solve conservation equations, simulating the propagation in a pipe between two chambers. The sensitivity analysis has pointed out that the parameters that are influenced by the propagation in the pipes are: needle lift, injected flow rate, pressure in each chamber, and volume. The perturbations reduce the effective pressure of injection and are influenced by pipe lengths and diameters.

scholarly journals Propagation of combustion waves in the shell–core energetic materials with external heat losses

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160937
Author(s):  
V. V. Gubernov ◽  
V. N. Kudryumov ◽  
A. V. Kolobov ◽  
A. A. Polezhaev
Keyword(s):  
Solid Fuel ◽  
Energetic Materials ◽  
Energetic Material ◽  
Front Propagation ◽  
Heat Losses ◽  
Combustion Waves ◽  
One Dimensional ◽  
The One ◽  
Composite Solid ◽  
Linear Stability Problem

In this paper, the properties and stability of combustion waves propagating in the composite solid energetic material of the shell–core type are numerically investigated within the one-dimensional diffusive-thermal model with heat losses to the surroundings. The flame speed is calculated as a function of the parameters of the model. The boundaries of stability are determined in the space of parameters by solving the linear stability problem and direct integration of the governing non-stationary equations. The results are compared with the characteristics of the combustion waves in pure solid fuel. It is demonstrated that a stable travelling combustion wave solution can exist for the parameters of the model for which the flame front propagation is unstable in pure solid fuel and it can propagate several times faster even in the presence of significant heat losses.

scholarly journals Calculation of Two-Phase Dispersed Droplet-In-Vapor Flows Including Normal Shock Waves

1978 ◽  
Vol 100 (3) ◽  
pp. 355-362 ◽  
Author(s):  
W. J. Comfort ◽  
T. W. Alger ◽  
W. H. Giedt ◽  
C. T. Crowe
Keyword(s):  
Shock Waves ◽  
Normal Shock ◽  
Vapor Flow ◽  
Dimensional Model ◽  
Two Phase ◽  
One Dimensional ◽  
Pressure Profiles ◽  
Pressure Equilibrium ◽  
Temperature And Pressure ◽  
Measured Pressure

A method for calculating quasi-one-dimensional, steady-state, two-phase dispersed droplet-in-vapor flow has been developed. The technique is applicable to both subsonic and supersonic single component flow in which normal shock waves may occur, and is the basis for a two-dimensional model. The flow is assumed to be inviscid except for droplet drag. Temperature and pressure equilibrium between phases is assumed, although this is not a requirement of the technique. Example calculations of flow in one-dimensional nozzles with and without normal shocks are given and compared with experimentally measured pressure profiles for both low quality and high quality two-phase steam-water flow.

The Effect of Water Droplets on the Relaxation Zone Developed Behind Strong Normal Shock Waves

1984 ◽  
Vol 106 (2) ◽  
pp. 154-159 ◽  
Author(s):  
Z. Rakib ◽  
O. Igra ◽  
G. Ben-Dor
Keyword(s):  
Shock Waves ◽  
Water Droplet ◽  
Normal Shock ◽  
Wave Flow ◽  
Water Droplets ◽  
Flow Properties ◽  
One Dimensional ◽  
Relaxation Zone ◽  
Droplet Concentration ◽  
Post Shock

The propagation of strong normal shock waves into quiescent argon gas seeded with water droplet is studied. For evaluating the effect of the water droplets on the post shock-wave flow field, i.e., the relaxation zone, the conservation equations appropriate to a steady, one-dimensional suspension flow are formulated and solved numerically. The solution, carried out for a range of shock Mach numbers 13 ≤ M ≤ 17 and a few different values for the water droplet concentration, indicates that the presence of the water droplets has a significant effect on the extent of the relaxation zone and on the values obtained for the flow properties throughout this zone.

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