Browsing by Subject "Reynolds number"

Now showing items 41-57 of 57

    • Conference Object  

      Solution of viscoplastic flows with the finite volume / multigrid method 

      Syrakos, A.; Georgiou, G. C.; Alexandrou, Andreas N. (National Technical University of Athens, 2013)
      We investigate the performance of the finite volume method in solving viscoplastic flows. The square lid-driven cavity flow of a Bingham plastic is chosen as the test case and the constitutive equation is regularised as ...
    • Article  

      Statistical measures of structural anisotropy in MHD turbulence subjected to mean shear and frame rotation 

      Kassinos, Stavros C.; Knaepen, B.; Wray, A. (2006)
      We consider homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field while being sheared in fixed and rotating frames. We take both the frame-rotation axis and the applied magnetic ...
    • Article  

      The steady annular extrusion of a Newtonian liquid under gravity and surface tension 

      Housiadas, Kostas D.; Georgiou, Georgios C.; Tsamopoulos, J. (2000)
      The steady extrusion of a Newtonian liquid through an annular die and its development outside and away from the die are studied under the influence of gravitational and surface tension forces. The finite element method ...
    • Article  

      Steady Herschel-Bulkley fluid flow in three-dimensional expansions 

      Alexandrou, Andreas N.; McGilvreay, T. M.; Burgos, G. (2001)
      In this paper we study steady flow of Herschel-Bulkley fluids in a canonical three-dimensional expansion. The fluid behavior was modeled using a regularized continuous constitutive relation, and the flow was obtained ...
    • Article  

      Structure and scales in turbulence modeling 

      Reynolds, W. C.; Langer, C. A.; Kassinos, Stavros C. (2002)
      The enstrophy of the large-scale energy-containing turbulence is proposed as the second turbulence scale for use, in conjunction with the turbulence energy, in two-scale one-point engineering turbulence models. Its transport ...
    • Conference Object  

      Structure anisotropy in MHD turbulence subjected to mean shear and frame rotation 

      Kassinos, Stavros C.; Wray, A. (Affiliation: Dept. of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, CyprusAffiliation: Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, United StatesAffiliation: Center for Turbulence Research, NASA Ames Research Center, United StatesCorrespondence Address: Kassinos, S.C.Dept. of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprusemail: kassinos@ucy.ac.cy, 2005)
      We consider homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field while being sheared in fixed and rotating frames. We take both the frame-rotation axis and the applied magnetic ...
    • Article  

      Structure-based turbulence model: Application to a rotating pipe flow 

      Poroseva, S. V.; Kassinos, Stavros C.; Langer, C. A.; Reynolds, W. C. (2002)
      A new approach for modeling the one-point turbulence statistics, which takes into account the information on turbulence structure, has been suggested in Kassinos and Reynolds (Report TF-61, Thermosciences Division, Department ...
    • Article  

      Structure-based turbulence modeling for wall-bounded flows 

      Kassinos, Stavros C.; Langer, C. A.; Haire, S. L.; Reynolds, W. C. (2000)
      The performance of Reynolds stress transport (RST) models in non-equilibrium flows is limited by the lack of information about two dynamically important effects: The role of energy-containing turbulence structure ...
    • Article  

      A study of various factors affecting Newtonian extrudate swell 

      Mitsoulis, Evan C.; Georgiou, Georgios C.; Kountouriotis, Zacharias (2012)
      Finite-element simulations have been undertaken for the benchmark problem of extrudate swell present in extrusion. Both cases of planar and axisymmetric domains were considered under laminar, isothermal, steady-state ...
    • Article  

      Surfactant destabilization and non-linear phenomena in two-fluid shear flows at small Reynolds numbers 

      Kalogirou, Anna; Papageorgiou, Demetrios T.; Smyrlis, Yiorgos-Sokratis (2012)
      The flow of two superposed fluids in a channel in the presence of an insoluble surfactant is studied. Asymptotic analysis when one of the layers is thin yields a system of coupled weakly non-linear evolution equations for ...
    • Article  

      Thixotropic flow past a cylinder 

      Syrakos, A.; Georgiou, Georgios C.; Alexandrou, Andreas N. (2014)
      We study the flow of a thixotropic fluid around a cylinder. The rheology of the fluid is described by means of a structural viscoplastic model based on the Bingham constitutive equation, regularised using the Papanastasiou ...
    • Article  

      Thixotropic flow past a cylinder 

      Syrakos, A.; Georgiou, G. C.; Alexandrou, Andreas N. (2014)
      We study the flow of a thixotropic fluid around a cylinder. The rheology of the fluid is described by means of a structural viscoplastic model based on the Bingham constitutive equation, regularised using the Papanastasiou ...
    • Article  

      Three dimensional flow around a circular cylinder confined in a plane channel 

      Kanaris, N.; Grigoriadis, D. G. E.; Kassinos, Stavros C. (2011)
      This paper presents two- and three-dimensional direct numerical simulations of the flow around a circular cylinder placed symmetrically in a plane channel. Results are presented in the Reynolds number range (based on the ...
    • Article  

      Three-dimensional numerical simulations of magnetohydrodynamic flow around a confined circular cylinder under low, moderate, and strong magnetic fields 

      Kanaris, N.; Albets, X.; Grigoriadis, D. G. E.; Kassinos, Stavros C. (2013)
      This paper presents three-dimensional direct numerical simulations of liquid metal flow around a circular cylinder placed symmetrically in a rectangular duct, under a wide range of magnetic field intensities. Results are ...
    • Article  

      The transport of a passive scalar in magnetohydrodynamic turbulence subjected to mean shear and frame rotation 

      Kassinos, Stavros C.; Knaepen, B.; Carati, D. (2007)
      We consider the transport of a passive scalar under the influence of homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field while being sheared in fixed and rotating frames. The ...
    • Article  

      Viscoplastic flow development in tubes and channels with wall slip 

      Philippou, Maria; Kountouriotis, Zacharias; Georgiou, Georgios C. (2016)
      The development of Bingham plastic flow in tubes and channels is investigated numerically using the Papanastasiou regularization and finite element simulations. It is assumed that slip occurs along the wall following ...
    • Conference Object  

      When structure makes a difference: Computation of rotating wall-bounded flows with an algebraic structure-based model 

      Kassinos, Stavros C.; Langer, C. A.; Kalitzin, G.; Iaccarino, G. (Affiliation: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, CyprusAffiliation: Center for Turbulence Research, Stanford University, Stanford, CA 94305, United StatesCorrespondence Address: Kassinos, S.C.Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprusemail: kassinos@ucy.ac.cy, 2005)
      Two linear eddy-viscosity models, the ν 2-f and κ-ω models, have been combined with an algebraic structure-based algorithm for the evaluation of the Reynolds stresses. This closure was originally designed as an integral ...