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.

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.

Design Considerations for Aerodynamically Quenching Gas Sampling Probes

1984 ◽  
Vol 106 (2) ◽  
pp. 460-466 ◽  
Author(s):  
L. Chiappetta ◽  
M. B. Colket
Keyword(s):  
Sensitivity Study ◽  
Operating Conditions ◽  
Dimensional Model ◽  
Quenching Temperature ◽  
One Dimensional ◽  
Trade Offs ◽  
Transfer Equations ◽  
Method Of Solution ◽  
Internal Aerodynamics ◽  
Temperature And Pressure

An aerodynamic quench is the most rapid method for quenching temperature and pressure-dependent chemical reactions. Attempts have been made to quench gas samples aerodynamically, but many of these attempts have been unsuccessful because of a lack of understanding of the internal aerodynamics of sampling probes. A one-dimensional model developed previously by the authors has been used for the design and analysis of aerodynamically quenching probes. This paper presents in detail the important aerodynamic and heat transfer equations used in the model, a description of the method of solution, and the results of a sensitivity study. These calculations demonstrate the limitations and important trade-offs in design and operating conditions of probes using an aerodynamic quench.

Mathematical modeling of dispersed media flows in the presence of nucleation, coagulation and phase transitions

2021 ◽  
Vol 102 (2) ◽  
pp. 14-24
Author(s):  
T.R. Amanbaev ◽  
◽  
G.E. Tilleuov ◽  
A. Zuparbekova ◽  
◽  
...  
Keyword(s):  
Phase Transitions ◽  
Saturation Temperature ◽  
Dimensional Model ◽  
Two Phase ◽  
One Dimensional ◽  
Dispersed Medium ◽  
Nucleation Model ◽  
Coagulation Equation ◽  
Media Flows ◽  
Vapor Temperature

A model of motion of a gas-dispersed medium in the presence of processes of nucleation, coagulation and phase transitions has been constructed. A homogeneous nucleation model is used to describe the nucleation process. It is believed that the process of cluster coagulation occurs due to their Brownian motion. The analysis of the solution of the coagulation equation in the particular case of monodisperse clusters in the presence of a source and sink of particles is carried out. To determine the rate of phase transitions the Hertz-KnudsenLangmuir formula is used. The calculations were carried out on the basis of a quasi-one-dimensional model within the equilibrium approximation (when the velocities and temperatures of the phases coincide). As a result of the study the main properties of the flow of a two-phase mixture in a channel in the presence of nucleation, coagulation, and phase transformations have been established. It is shown that the vapor temperature increases along the channel and reaches the saturation temperature at some distance from the channel entrance. Calculations have shown that the coagulation process has a rather strong effect on the distribution of cluster sizes along the channel.

Dependence of Shock Characteristics on Droplet Size in Supersonic Two-Phase Mixtures

1980 ◽  
Vol 102 (1) ◽  
pp. 54-58 ◽  
Author(s):  
W. J. Comfort ◽  
C. T. Crowe
Keyword(s):  
Shock Waves ◽  
Droplet Size ◽  
Size Dependence ◽  
Supersonic Nozzle ◽  
Mass Effect ◽  
Normal Shock ◽  
Virtual Mass ◽  
Two Phase ◽  
Phase Mixture ◽  
Phase Normal

In a dispersed two-phase flow, the mixture chokes at a velocity well below the vapor choking velocity, as shown by the velocity at the throat of a converging-diverging, two-phase, supersonic nozzle. The formation and abruptness of a normal shock wave in a two-phase mixture depends strongly on the coupling between phases, particularly upon droplet size. As droplet size becomes small, the mixture behaves as a continuum, and sharp discontinuities can occur at velocities above the two-phase choking velocity but below the vapor sonic velocity. An approximate analysis is performed to incidate the droplet size at which continuum behavior might be expected to occur. A numerical model, which includes the drag, buoyancy, Basset force, and the force associated with the virtual mass effect, is used to show droplet-size dependence in two-phase normal shock waves. For the examples presented, continuum behavior apparently is approached at droplet diameters between 1 and 2 μm, even through normal shock waves.

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