Browsing by Author "Valougeorgis, D."
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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 ... 
An analytical discreteordinates solution of the Smodel kinetic equations for flow in a cylindrical tube
Siewert, C. E.; Valougeorgis, D. (2002)An integrodifferential form of the linearized Smodel kinetic equations for describing flow in a cylindrical tube is projected in such a way as to yield a pair of coupled transport equations that defines the desired ... 
Analytical lattice Boltzmann solutions for thermal flow problems
Valougeorgis, D.; Naris, S. (2003)Analytical solutions based on two 13bit (hexagonal and square) and one 17bit square lattice Boltzmann BGK models have been obtained for the Couette flow, with a temperature gradient at the boundaries. The analytical ... 
An analytical solution of the Smodel kinetic equations
Valougeorgis, D. (2003)An analytical variation of the discrete ordinates method is used to establish a concise and accurate solution to the plane Poiseuille and thermal creep problems based on the Smodel kinetic equations. The results are of ... 
Application of the integromoment method to steadystate twodimensional rarefied gas flows subject to boundary induced discontinuities
Varoutis, S.; Valougeorgis, D.; Sharipov, F. (2008)The computational efficiency of the integromoment method for solving steadystate twodimensional rarefied gas flows is investigated. The twodimensional boundary driven flow of a single gas in a cavity is used as a model ... 
Boundarydriven nonequilibrium gas flow in a grooved channel via kinetic theory
Naris, S.; Valougeorgis, D. (2007)The nonequilibrium flow of a gas in a twodimensional 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 ... 
Comparative study between computational and experimental results for binary rarefied gas flows through long microchannels
Szalmas, L.; Pitakarnnop, J.; Geoffroy, S.; Colin, S.; Valougeorgis, D. (2010)A comparative study between computational and experimental results for pressuredriven binary gas flows through long microchannels is performed. The theoretical formulation is based on the McCormack kinetic model and the ... 
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 ... 
Concise and accurate solutions to halfspace binarygas flow problems defined by the McCormack model and speculardiffuse wall conditions
Siewert, C. E.; Valougeorgis, D. (2004)An analytical version of the discreteordinates method (the ADO method) is used to establish concise and particularly accurate solutions to the viscousslip and the halfspace thermalcreep problems for a binary gas mixture. ... 
Conductive heat transfer in a rarefied polyatomic gas confined between coaxial cylinders
Tantos, C.; Valougeorgis, D.; Pannuzzo, M.; Frezzotti, A.; Morini, G. L. (2014)The conductive heat transfer through rarefied gases composed by rigid rotators and confined between coaxially placed cylinders maintained at different temperatures is investigated on the basis of the Holway and Rykov kinetic ... 
Conductive heat transfer in rarefied polyatomic gases confined between parallel plates via various kinetic models and the DSMC method
Tantos, C.; Valougeorgis, D.; Frezzotti, A. (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 ... 
Couette flow with heat transfer in the whole range of the Knudsen number
Misdanitis, S.; Valougeorgis, D. (2008)The steadystate onedimensional flow of a gas between two parallel plates moving with relative velocity and maintained at different temperatures is examined on the basis of the nonlinear BhatnagarGrossKrook (BGK) model ... 
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 ... 
Design of micro distribution systems consisting of long channels with arbitrary cross sections
Misdanitis, S.; Valougeorgis, D. (2012)Gas flows through long microchannels of various cross sections have been extensively investigated over the years both numerically and experimentally. In various technological applications including microfluidics, these ... 
Design of steadystate isothermal gas distribution systems consisting of long tubes in the whole range of the Knudsen number
Misdanitis, S.; Valougeorgis, D. (2011)A novel algorithm is developed to solve steadystate isothermal vacuum gas dynamics flows through pipe networks consisting of long tubes based on linear kinetic theory. For a pipe network of known geometry the algorithm ... 
Discrete velocity modelling of gaseous mixture flows in MEMS
Naris, S.; Valougeorgis, D.; Sharipov, F.; Kalempa, D. (2004)The need of developing advanced microelectromechanical systems (MEMS) has motivated the study of fluidthermal flows in devices with microscale 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 twodimensional linearized BhatnagarGrossKrook ... 
DSMC simulation of pressure driven binary rarefied gas flows through short microtubes
Szalmas, L.; Valougeorgis, D.; Colin, S. (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 ... 
Efficient simulation of rarefied gas flows through tubes of finite length based on kinetic model equations
Pantazis, S.; Valougeorgis, D. (2011)The flow of a rarefied gas through tubes of circular crosssection and finite length, driven by arbitrarily large gradients of pressure is simulated in a computationally efficient manner based on kinetic model equations. ... 
End corrections for rarefied gas flows through capillaries of finite length
Pantazis, S.; Valougeorgis, D.; Sharipov, F. (2013)The influence of end effects on rarefied gas flows through moderately long capillaries is investigated by implementing the concept of effective capillary length, representing a sum of the real length of capillary and its ...