Parcourir par auteur "Naris, S."
Voici les éléments 1-20 de 21
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Acceleration schemes of the discrete velocity method: Gaseous flows in rectangular microchannels
Valougeorgis, D.; Naris, S. (2003)The convergence rate of the discrete velocity method (DVM), which has been applied extensively in the area of rarefied gas dynamics, is studied via a Fourier stability analysis. The spectral radius of the continuum form ... -
Analytical lattice Boltzmann solutions for thermal flow problems
Valougeorgis, D.; Naris, S. (2003)Analytical solutions based on two 13-bit (hexagonal and square) and one 17-bit square lattice Boltzmann BGK models have been obtained for the Couette flow, with a temperature gradient at the boundaries. The analytical ... -
Boundary-driven nonequilibrium gas flow in a grooved channel via kinetic theory
Naris, S.; Valougeorgis, D. (2007)The nonequilibrium flow of a gas in a two-dimensional grooved channel, due to the motion of the wall of the channel, is investigated based on kinetic theory. The presence of the rectangular grooves that are placed periodically ... -
Computational and experimental study of gas flows through long channels of various cross sections in the whole range of the Knudsen number
Varoutis, S.; Naris, S.; Hauer, V.; Day, C.; Valougeorgis, D. (2009)A computational and experimental study has been performed for the investigation of fully developed rarefied gas flows through channels of circular, orthogonal, triangular, and trapezoidal cross sections. The theoretical- ... -
Design and optimization of a Holweck pump via linear kinetic theory
Naris, S.; Koutandou, E.; Valougeorgis, D. (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 ... -
Discrete velocity modelling of gaseous mixture flows in MEMS
Naris, S.; Valougeorgis, D.; Sharipov, F.; Kalempa, D. (2004)The need of developing advanced micro-electro-mechanical systems (MEMS) has motivated the study of fluid-thermal flows in devices with micro-scale geometries. In many MEMS applications the Knudsen number varies in the range ... -
The driven cavity flow over the whole range of the Knudsen number
Naris, S.; Valougeorgis, D. (2005)The flow of a rarefied gas in a rectangular enclosure due to the motion of the upper wall is solved over the whole range of the Knudsen number. The formulation is based on the two-dimensional linearized Bhatnagar-Gross-Krook ... -
Flow of gaseous mixtures through rectangular microchannels driven by pressure, temperature, and concentration gradients
Naris, S.; Valougeorgis, D.; Kalempa, D.; Sharipov, F. (2005)The flow of binary gaseous mixtures through rectangular microchannels due to small pressure, temperature, and molar concentration gradients over the whole range of the Knudsen number is studied. The solution is based on a ... -
Formulation and stability analysis of rapidly convergent iteration schemes for the 2-D linearized BGK equation
Lihnaropoulos, J.; Naris, S.; Valougeorgis, D. (2007)Various H-N rapidly convergent schemes are proposed to speed up the slow convergence of the iterative solution of 2-D linearized Bhatnagar-Gross-Krook (BGK) kinetic equation containing up to the first moments of the ... -
Gas flow and heat transfer simulation in MEMS via a mesoscopic approach
Naris, S.; Valougeorgis, D.; Kalempa, D.; Sharipov, F. (2004)The flow problem of binary gaseous mixtures in rectangular micro channels due to small pressure, temperature and molar concentration gradients over the whole range of the Kn number is solved. The solution is based on a ... -
Gas flow in a grooved channel due to pressure and temperature gradients
Naris, S.; Valougeorgis, D. (2006)The flow of a gas in a grooved nano or micro channel, due to the imposed pressure and temperature gradients in the longitudinal direction, is investigated via a kinetic approach. The solution is valid in the whole range ... -
Gaseous mixture flow between two parallel plates in the whole range of the gas rarefaction
Naris, S.; Valougeorgis, D.; Kalempa, D.; Sharipov, F. (2004)The flow of binary gaseous mixtures between two parallel plates driven by gradients of pressure, temperature and concentration is studied, based on the McCormack model of the Boltzmann equation. The coupled kinetic equations ... -
Hybrid modeling of time-dependent rarefied gas expansion
Vargas, M.; Naris, S.; Valougeorgis, D.; Pantazis, S.; Jousten, K. (2014)The time evolution of the flow parameters in a system where gas is expanded from a high pressure chamber through a tube toward a low pressure chamber is investigated. During the process, the pressure in the two chambers ... -
Kinetic modeling of a tapered Holweck pump
Naris, S.; Tantos, C.; Valougeorgis, D. (2014)The Holweck pump is a device widely used in many pumping systems. It can be a self-standing device or part of a multi-stage system, usually combined with a turbo-molecular pump (TMP). In the present work, an existing ... -
Nonlinear vacuum gas flow through a short tube due to pressure and temperature gradients
Pantazis, S.; Naris, S.; Tantos, C.; Valougeorgis, D.; Andre, J.; Millet, F.; Perin, J. P. (2013)The flow of a rarefied gas through a tube due to both pressure and temperature gradients has been studied numerically. The main objective is to investigate the performance of a mechanical vacuum pump operating at low ... -
Pressure- and Temperature-Driven Flow Through Triangular and Trapezoidal Microchannels
Ritos, K.; Lihnaropoulos, Y.; Naris, S.; Valougeorgis, D. (2011)A detailed study of pressure- and temperature-driven flows through long channels of triangular and trapezoidal cross sections is carried out. Due to the imposed pressure and temperature gradients there is a combined gas ... -
Rarefied gas flow in a triangular duct based on a boundary fitted lattice
Naris, S.; Valougeorgis, D. (2008)The rarefied fully developed flow of a gas through a duct of a triangular cross section is solved in the whole range of the Knudsen number. The flow is modelled by the BGK kinetic equation, subject to Maxwell diffuse ... -
Rarefied gas mixture flow between plates of arbitrary length due to small pressure difference
Tantos, C.; Naris, S.; Valougeorgis, D. (2012)The linearized flow of a binary gas mixture between two parallel plates of any length driven by a small pressure difference is numerically solved based on the McCormack kinetic model. In this case the flow is not fully ... -
Shear driven micro-flows of gaseous mixtures
Valougeorgis, D.; Naris, S. (2004)A mesoscale kinetic-type approach is proposed to solve shear driven micro flows of binary gas mixtures in MEMS. The coupled linear integral-differential equations, which formally describe the flow, are solved using the ... -
Shear driven micro-flows of gaseous mixtures
Naris, S.; Valougeorgis, D. (2006)A mesoscale kinetic-type approach is proposed to solve shear driven micro flows of binary gas mixtures in MEMS. The coupled linear integro-differential equations, which formally describe the flow, are solved using the ...