Boundary conditions in a multicomponent gas mixture flow past a volatile nonspherical surface at knudsen numbers 0.01 and 0.3

1997 ◽  
Vol 70 (4) ◽  
pp. 668-673
Author(s):  
E. I. Alekhin
Keyword(s):  
Boundary Conditions ◽  
Gas Mixture ◽  
Mixture Flow ◽  
Flow Past ◽  
Knudsen Numbers ◽  
Multicomponent Gas ◽  
Multicomponent Gas Mixture

Method to optimize high-pressure, multicomponent gas mixing

1976 ◽  
Vol 41 (6) ◽  
pp. 960-963 ◽  
Author(s):  
R. Scacci
Keyword(s):  
High Pressure ◽  
Gas Mixture ◽  
Gas Mixing ◽  
Arbitrary Size ◽  
Multicomponent Gas ◽  
Pressure Storage ◽  
Multicomponent Gas Mixture

By use of the equations derived herein, a method is outlined to determine the optimum filing sequence and to obtain the maximum possible pressure when two or more pure high-pressure gases are to be transferred to a receiver cylinder in order to prepare a multicomponent gas mixture. The method is valid for any number of gas components, originating from high-pressure storage cyclinders of arbitrary size and pressure and for a receiver cylinder to contain initially one or more of the component gases. Percentage concentrations within 1% of desired are easily obtained with this method.

Multicomponent gas mixture analysis using a single tin oxide sensor and dynamic pattern recognition

2001 ◽  
Vol 1 (3) ◽  
pp. 207-213 ◽  
Author(s):  
E. Llobet ◽  
R. Ionescu ◽  
S. Al-Khalifa ◽  
J. Brezmes ◽  
X. Vilanova ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Tin Oxide ◽  
Gas Mixture ◽  
Mixture Analysis ◽  
Dynamic Pattern ◽  
Multicomponent Gas ◽  
Multicomponent Gas Mixture

scholarly journals The simulation of the atmospheric flow with emmisions

2019 ◽  
Vol 213 ◽  
pp. 02050
Author(s):  
Martin Kyncl ◽  
Jaroslav Pelant
Keyword(s):  
Boundary Conditions ◽  
Gas Flow ◽  
Gravitational Force ◽  
Ground Surface ◽  
Gas Mixture ◽  
Computational Results ◽  
Mixture Flow ◽  
Atmospheric Flow ◽  
Wall Functions ◽  
Computational Code

The aim of this work is to simulate the flow of the passive gas mixture and estimate the resulting concentration of the potentionally dangerous pollutant emmisions. We assume non-stationary compressible gas flow in the gravitational field described by the system of the RANS equations, equipped with the equation for the concentration of additional specie. Due to gravitational force effect we modify the boundary conditions and data resulting admissible situations. The real simulations of the atmospheric flow require the use of the wall functions for the boundary condition simulating the ground surface with given roughness. We show the modification of such wall functions. The computational results are obtained with the own-developed CFD code for the compressible turbulent mixture flow. The originality of this work lies with the special handling of the boundary conditions, and own computational code.

scholarly journals Properties of the aggregated quasi-hydrodynamic system of equations for a homogeneous gas mixture with a common regularizing velocity

2021 ◽  
pp. 1-26
Author(s):  
Alexander Anatolievich Zlotnik ◽  
Anna Sergeevna Fedchenko
Keyword(s):  
Original System ◽  
New Technique ◽  
Gas Mixture ◽  
System Of Equations ◽  
Symmetric Form ◽  
Hydrodynamic System ◽  
Constant Solution ◽  
Multicomponent Gas ◽  
A New Technique ◽  
Multicomponent Gas Mixture

We study a quasi-hydrodynamic system of equations for a homogeneous (with common velocity and temperature) multicomponent gas mixture in the absence of chemical reactions, with a regularizing velocity common for the components. We derive the entropy balance equation with a non-negative entropy production taking into account the diffusion fluxes of the mixture components. In the absence of diffusion fluxes, a system of equations linearized at a constant solution is constructed by a new technique, In the absence of diffusion fluxes, a system of equations linearized on a constant solution is constructed by a new technique. It is reduced to a symmetric form, the L^2-dissipativity of its solutions is proved, and a degeneration (with respect to the densities of the mixture components) of the parabolicity property for the original system is established. Actually, the system has the composite type. The obtained properties strictly reflect its physical correctness and dissipative nature of the quasi-hydrodynamic regularization.

scholarly journals Application of a hybrid large-particle method for calculating multicomponent gas mixture flows

2019 ◽  
pp. 489-497
Author(s):  
Д.В. Садин
Keyword(s):  
Large Particle ◽  
Order Approximation ◽  
Particle Method ◽  
Numerical Results ◽  
Gas Mixture ◽  
Wide Range ◽  
Multicomponent Gas ◽  
Self Similar ◽  
Similar Solutions ◽  
Multicomponent Gas Mixture

Статья посвящена обобщению гибридного метода крупных частиц для численного моделирования течений многокомпонентных газовых смесей при наличии границ раздела газов с различными термодинамическими свойствами. Метод относится к алгоритмам сквозного расчета разрывов. Разностная схема является консервативной, однородной и имеет второй порядок аппроксимации по пространству и времени на гладких решениях. Результаты проверки на тестовых задачах в широком диапазоне чисел Маха и отношений газодинамических параметров подтвердили работоспособность метода. Выполнен анализ численных ошибок в окрестности контактных разрывов на сетках различного разрешения, свидетельствующий о сходимости результатов расчета к автомодельным решениям. This paper is devoted to a generalization of a hybrid large-particle method for the numerical simulation of multicomponent gas mixture flows in the presence of gas interfaces with various thermodynamic properties. The method belongs to the class of shock-capturing and interface-capturing algorithms. The employed difference scheme is conservative and uniform and possesses the second order approximation in space and time on smooth solutions. The obtained numerical results show the efficiency of the method in a wide range of Mach numbers and ratios of gas dynamic parameters. The error analysis performed near the contact discontinuities on grids of various resolutions confirms the convergence of numerical results to the self-similar solutions.

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