Πλοήγηση ανά Θέμα "Gases"
Αποτελέσματα 1-20 από 38
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Analysis of gas separation, conductance and equivalent single gas approach for binary gas mixture flow expansion through tubes of various lengths into vacuum
(2016)The steady-state binary gas mixture expansion through tubes of various lengths into vacuum is considered, focusing on the intensity of gas separation, the computation of conductance and the implementation of the equivalent ... -
Applying Long Short-Term Memory Networks for natural gas demand prediction
(2019)Long Short-Term Memory (LSTM) algorithm encloses the characteristics of the advanced recurrent neural network methods and is used in this research study to forecast the natural gas demand in Greece in the short-term. LSTM ... -
Computational investigation and parametrization of the pumping effect in temperature-driven flows through long tapered channels
(2017)The temperature-driven rarefied gas flow and the associated pumping effects through long channels with linearly diverging or converging cross sections are computationally investigated. The implemented kinetic modeling is ... -
Conductive heat transfer in rarefied binary gas mixtures confined between parallel plates based on kinetic modeling
(2018)The kinetic model introduced by Kosuge (2009) is implemented to solve heat transfer through rarefied binary gas mixtures confined between two parallel plates maintained at different temperatures. The results have been found ... -
Conductive heat transfer in rarefied polyatomic gases confined between parallel plates via various kinetic models and the DSMC method
(2015)The conductive heat transfer through rarefied polyatomic gases confined between parallel plates maintained at different temperatures is investigated. The approach is based on three kinetic models namely the Holway, Rykov ... -
Design and optimization of a Holweck pump via linear kinetic theory
(2012)The Holweck pump is widely used in the vacuum pumping industry. It can be a self standing apparatus or it can be part of a more advanced pumping system. It is composed by an inner rotating cylinder (rotor) and an outer ... -
Design guidelines for thermally driven micropumps of different architectures based on target applications via kinetic modeling and simulations
(2019)The manufacturing process and architecture of three Knudsen type micropumps are discussed and the associated flow performance characteristics are investigated. The proposed fabrication process, based on the deposition of ... -
Determination of nitrous oxide concentration using a solid-electrolyte amperometric sensor
(2019)Herein, are presented the results of the investigation of an electrochemical sensor, based on oxygen-conducting yttria stabilized zirconia (YSZ) solid-state electrolyte, used for the determination of nitrous oxide in gas ... -
DSMC simulation of pressure driven binary rarefied gas flows through short microtubes
(2011)Binary gas flows driven by pressure gradient through short microtubes are studied by using an upgraded version of the Direct Simulation Monte Carlo (DSMC) method. Two types of mixtures, He/Xe and Ne/Ar, are examined. Several ... -
Effect of vibrational degrees of freedom on the heat transfer in polyatomic gases confined between parallel plates
(2016)Conductive stationary heat transfer through rarefied nonpolar polyatomic gases, confined between parallel plates maintained at different temperatures, is investigated. It is assumed that gas molecules possess both rotational ... -
An electrochemical method for the determination of concentration and diffusion coefficient of ammonia‑nitrogen gas mixtures
(2018)In the present investigation an electrochemical method for the determination of concentration and diffusion coefficient of ammonia in nitrogen (NH3/N2) is proposed by the means of a solid-state amperometric sensor based ... -
Experimental analysis of heat transfer between a heated wire and a rarefied gas in an annular gap with high diameter ratio
(2012)In this paper a first experimental attempt is performed to measure heat conduction through rarefied air at rest contained between two concentric cylinders. The heat transfer between a heated platinum wire having a diameter ... -
Forecasting of day-ahead natural gas consumption demand in Greece using adaptive neuro-fuzzy inference system
(2020)(1) Background: Forecasting of energy consumption demand is a crucial task linked directly with the economy of every country all over the world. Accurate natural gas consumption forecasting allows policy makers to formulate ... -
Gas flow towards an adsorbing planar wall subject to partial gas-surface thermal accommodation
(2016)The steady half-space single gas flow driven by an adsorbing planar wall is investigated based on the solution of the BGK kinetic model. The mass and heat transfer between the gas and the plate are characterized by the ... -
Gas mixing and final mixture composition control in simple geometry micro-mixers via DSMC analysis
(2019)The mixing process of two pressure driven steady-state rarefied gas streams flowing between two parallel plates was investigated via DSMC (Direct Simulation Monte Carlo) for different combinations of gases. The distance ... -
Gas-surface interaction in rarefied gas flows through long capillaries via the linearized Boltzmann equation with various boundary conditions
(2022)Reliable gas–surface interaction modeling is of major importance in consistent simulation of rarefied gas flows with applications in vacuum technology and micro-electromechanical systems. The effectiveness of the most ... -
Implementing fuzzy cognitive maps with neural networks for natural gas prediction
(2018)The goal of this research study is to test the hardiness of a novel hybrid computational intelligence model in day-ahead natural gas demand prediction. The proposed model combines an evolutionary learned FCM method with a ... -
Linear harmonic oscillatory rarefied gas flow with arbitrary frequency in comb finger blocks
(2021)The linear oscillatory two-dimensional rarefied gas flow in the zig-zag channel between the shuttle and stator fingers of typical comb elements, due to the harmonic motion of the shuttle finger with arbitrary frequency, ... -
Modeling of complex gas distribution systems operating under any vacuum conditions: Simulations of the ITER divertor pumping system
(2016)An integrated software tool for modeling and simulation of complex gas distribution systems operating under any vacuum conditions is presented and validated. The algorithm structure includes (a) the input geometrical and ... -
Modeling of time-dependent gas pumping networks in the whole range of the Knudsen number: Simulation of the ITER dwell phase
(2020)A hybrid time-dependent algorithm to simulate the transient response of gas distribution systems of arbitrary size and complexity, in the whole range of the Knudsen number, is proposed. The pressure evolution in the vessels ...