scholarly journals Analysis of sub-grid scale modeling of the ideal-gas equation of state in hydrogen–oxygen premixed flames

2019 ◽  
Vol 37 (2) ◽  
pp. 2345-2351 ◽  
Author(s):  
Guillaume Ribert ◽  
Pascale Domingo ◽  
Luc Vervisch
Keyword(s):  
Equation Of State ◽  
Premixed Flames ◽  
Ideal Gas ◽  
Scale Modeling ◽  
The Ideal

Simple Predictions for the Sonic Conditions in a Real Gas

1977 ◽  
Vol 99 (1) ◽  
pp. 217-225 ◽  
Author(s):  
P. A. Thompson ◽  
D. A. Sullivan
Keyword(s):  
Equation Of State ◽  
Closed Form ◽  
Thermodynamic Parameters ◽  
Ideal Gas ◽  
Accurate Prediction ◽  
Bernoulli Equation ◽  
Real Gas ◽  
Similarity Principle ◽  
Isentropic Flow ◽  
The Ideal

The steady isentropic flow of a fluid which satisfies an arbitrary equation of state is treated, with emphasis on the prediction of pressure, density, velocity, and massflow at the sonic state. The isentrope P(v) is described by a limited number of thermodynamic parameters, the most important ones being the soundspeed c and fundamental derivative Γ. Using this description, an application of the Bernoulli equation and appropriate thermodynamic relations yields simple closed-form predictions for the sonic state. These predictions are recognizable as generalizations of well-known ideal gas formulas, but are applicable to fluids very far removed from the ideal gas state, even including liquids. Comparisons in several cases for which precise independent solutions are available suggest that the methods found here are accurate. A derived similarity principle allows the accurate prediction of sonic properties from any single given sonic property.

Extremes in Dependences of Enthalpy and Entropy of Saturated Vapour on Temperature

1997 ◽  
Vol 62 (5) ◽  
pp. 679-695
Author(s):  
Josef P. Novák ◽  
Anatol Malijevský ◽  
Jaroslav Dědek ◽  
Jiří Oldřich
Keyword(s):  
Heat Capacity ◽  
Equation Of State ◽  
Ideal Gas ◽  
Corresponding States ◽  
Saturated Vapour ◽  
Enthalpy And Entropy ◽  
The Ideal

It was proved that the enthalpy of saturated vapour as a function of temperature has a maximum for all substances. The dependence of the entropy of saturated vapour on temperature can be monotonous, has a minimum and a maximum, or has only a maximum. The thermodynamic relations were derived for the existence of the extremes which enable their computation from the knowledge of dependence of the ideal-gas heat capacity on temperature and an equation of state. A method based on the theorem of corresponding states was proposed for estimating the extremes, and its results were compared with literature data. The agreement between the literature and estimated temperatures corresponding to the extremes is very good. The procedure proposed can serve for giving precision to the H-p and T-S diagrams commonly used in applied thermodynamics.

A comparative study of thermodynamic models to describe the VLE of the ternary electrolytic mixture H2O–NH3–CO2

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Licianne P. S. Rosa ◽  
Natan Cruz ◽  
Glória M. N. Costa ◽  
Karen V. Pontes
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Equation Of State ◽  
Activity Coefficient ◽  
Vapor Phase ◽  
Large Scale ◽  
Optimization Problems ◽  
Ideal Gas ◽  
Simultaneous Optimization ◽  
The Ideal

Abstract This study aims to ascertain the influence of the activity coefficient model and equation of state for predicting the vapor–liquid equilibrium (VLE) of the multi-electrolytic system H2O–NH3–CO2. The non-idealities of the liquid phase are described by the eUNIQUAC and eNRTL models. The vapor phase is modeled with the Nakamura equation, which is compared with the ideal gas assumption. The models are validated with experimental data from literature on total pressure and ammonia partial pressure. Results show that the models UNIQUAC and NRTL without dissociation can only reproduce the experimental conditions in the absence of CO2. When the electrolytic term is considered, the eUNIQUAC model is able to reproduce the experimental data with greater accuracy than the eNRTL. The equation of state which describes the vapor phase plays no major role in the accuracy of the VLE prediction in the operational conditions evaluated here. Indeed, the accuracy relies on the activity coefficient, therefore the ideal gas equation can be considered if the non-idealities of the liquid phase are described by a well-tuned model. These findings could be useful for equipment design, flowsheet simulations and large-scale simultaneous optimization problems.

scholarly journals CONCERNING THE EQUATION OF STATE FOR A PARTIALLY IONIZED SYSTEM

2009 ◽  
Vol 23 (20n21) ◽  
pp. 3968-3978
Author(s):  
GEORGE A. BAKER
Keyword(s):  
Equation Of State ◽  
Ideal Gas ◽  
Thermodynamic Quantities ◽  
Low Density ◽  
Cellular Model ◽  
Density Region ◽  
Cellular Models ◽  
Maxwell Construction ◽  
Actual Region ◽  
The Ideal

I will discuss the expansion of various thermodynamic quantities about the ideal gas in powers of the electric charge, and I will discuss some cellular models. The first type of cellular model is appropriate for hydrogen. The second type is for Z > 1. It has the independent electron approximation within the atoms. These models are cross compared and minimal regions of validity are determined. The actual region of validity is expected to be larger. In the cellular models, the phase boundaries for liquid-gas transitions are found. For the second type of cellular model, in the part of the low-temperature, low-density region where there is not much expectation of validity of these methods, a non-thermodynamic region is found. I have devised a construction, similar in spirit to the Maxwell construction, to bridge this region so as to leave a thermodynamically valid equation of state. The non-thermodynamic region does not occur in hydrogen and it seems to be due to the inadequacy of the aforementioned approximation in that region.

Systems and states

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Equation Of State ◽  
Ideal Gas ◽  
State Function ◽  
System State ◽  
Molecular Interpretation ◽  
Definition Of ◽  
Key Terms ◽  
Boyle’S Law ◽  
The Ideal

An introduction to thermodynamics, its scope, applications and importance. Definition and exploration of key terms such as system, state, surroundings, boundary, intensive state function, extensive state function, and change in state. Definition of a key intensive state function, pressure. Introduction of the concept of an equation-of-state, with Boyle’s law as an example. Introduction to the ideal gas. Molecular interpretation of pressure.

scholarly journals Equation of state problems in inertial confinement fusion

1985 ◽  
Vol 3 (3) ◽  
pp. 207-236 ◽  
Author(s):  
Shalom Eliezer ◽  
Aaron D. Krumbein ◽  
Henrique Szichman ◽  
Heinrich Hora
Keyword(s):  
Equation Of State ◽  
Inertial Confinement Fusion ◽  
Ideal Gas ◽  
Inertial Confinement ◽  
Self Similarity ◽  
Confinement Fusion ◽  
Linear Force ◽  
Isothermal Diagrams ◽  
Two Temperature ◽  
The Ideal

An analysis is made of the equation of state problems in inertial confinement fusion. After reviewing the need for compression for inertial confinement fusion along the lines of the classical self similarity model which is derived in a modified way with indications of the equation of state, the problems of the central core ignition are examined with respect to the equation of state. A basic difficulty is elaborated in the ‘scape goat diagram’. After describing alternative compression schemes such as non-linear force and cannon ball, the two temperature equation of state is developed with electronic and ionic contributions following the ideal gas, the Debye-Grüneisen equation of state, the solid-gas interpolation and the SESAME tables. A remarkable discrepancy for the isothermal diagrams is shown between the general result and the result based on the earlier McCarthy–Kalitkin scheme.

scholarly journals Solutions of the Noh problem for various equations of state using LIE groups

2000 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
ROY A. AXFORD
Keyword(s):  
Equation Of State ◽  
Lie Groups ◽  
Equations Of State ◽  
Spherical Geometry ◽  
Ideal Gas ◽  
Explicit Solutions ◽  
Special Case ◽  
General Method ◽  
The Ideal

A method for developing invariant equations of state (EOS) for which solutions of the Noh problem will exist is developed. The ideal gas EOS is shown to be a special case of the general method. Explicit solutions of the Noh problem in planar, cylindrical, and spherical geometry are determined for a Mie–Gruneisen and the stiff gas equation of state.

NUMERICAL SIMULATION OF THE EQUATION OF STATE FOR HADRONIC MATTER WITHIN THE STRING MODEL

1989 ◽  
Vol 04 (02) ◽  
pp. 437-449 ◽  
Author(s):  
K. SAILER ◽  
B. MÜLLER ◽  
W. GREINER
Keyword(s):  
Numerical Simulation ◽  
Asymptotic Behavior ◽  
Mass Spectrum ◽  
Equation Of State ◽  
Bosonic Strings ◽  
String Model ◽  
Ideal Gas ◽  
Hadronic Matter ◽  
Hadronic Resonances ◽  
The Ideal

The mass spectrum of classical open bosonic strings and the equation of state of their ideal gas has been found by means of numerical simulation. The mass spectrum obtained has an exponential asymptotic behavior and is in good qualitative agreement with the experimental data on hadronic resonances. It has been established that the temperature of the ideal gas of classical open bosonic strings cannot exceed a maximal value determined by the asymptotic behavior of the mass spectrum.

Isentropic Compressible Flow for Non-Ideal Gas Models for a Venturi

2004 ◽  
Vol 126 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Kenneth C. Cornelius ◽  
Kartik Srinivas
Keyword(s):  
Mach Number ◽  
Equation Of State ◽  
Compressible Flow ◽  
Mathematical Formulation ◽  
Compressibility Factor ◽  
Ideal Gas ◽  
Ideal Gas Law ◽  
Thermodynamic Variables ◽  
Analytical Result ◽  
The Ideal

The non-ideal gas equations and mathematical formulation developed in this work using the compressibility factor in the equation of state closely resemble the derivations used for the ideal gas mathematical formulation for a direct comparison of the differences between the ideal versus the non-ideal gas law. The local Mach number is defined for the non-ideal gas. The plenum total variables used in compressible flow are expressed in terms of the local Mach number for the polytrope and Rayleigh models. A power law relationship is derived between the thermodynamic variables that allow an analytical result for the mass flow under certain constraints.

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