• Conference Object  

      3-D flow of Herschel-Bulkley fluids 

      Burgos, Gilmer R.; Alexandrou, Andreas N. (ASME, 1998)
      The flow of Herschel-Bulkley fluids through a sudden 3-D square with expansion height ratio of 2:1 is studied numerically by solving the mass and momentum conservation equations along with a continuous constitutive relation. ...
    • Article  

      An analytical solution for rapidly distorted turbulent shear flow in a rotating frame 

      Akylas, Evaggelos; Kassinos, Stavros C.; Langer, A. C. (2006)
      In this study we apply rapid distortion theory to the case of nonstratified homogeneous turbulence that is sheared in a frame that counter-rotates at a rate that matches in magnitude the rotation associated with the mean ...
    • Article  

      The ASBM-SA turbulence closure: Taking advantage of structure-based modeling in current engineering CFD codes 

      Panagiotou, C. F.; Kassinos, Stavros C.; Aupoix, B. (2015)
      Structure-based turbulence models (SBM) carry information about the turbulence structure that is needed for the prediction of complex non-equilibrium flows. SBM have been successfully used to predict a number of canonical ...
    • Conference Object  

      Computational fluid dynamics (CFD) Simulations of aerosol deposition in the lungs 

      Koullapis, P. G.; Kassinos, Stavros C.; Lin, C.-L. (TSFP-9, 2015)
      In the current study, Large Eddy Simulations (LES) are used to investigate the transport and deposition of inhaled aerosol particles (dp = 0.1, 0.5, 1, 2.5, 5, 10 μm) in a realistic geometry of the human airways under ...
    • Article  

      The contribution of active and inactive structures to the statistics of a turbulent pipe flow 

      Stylianou, F. S.; Kassinos, Stavros C. (2017)
      The current study is a short follow-up to our most recent work (Stylianou et al., 2016), where among other things we have presented an effective criterion suitable for distinguishing large-scale coherent structures with ...
    • Article  

      Core of the magnetic obstacle 

      Votyakov, E. V.; Kassinos, Stavros C. (2010)
      Rich recirculation patterns have been recently discovered in the electrically conducting flow subject to a local external magnetic termed "the magnetic obstacle" (E.V. Votyakov, Y. Kolesnikov, O. Andreev, E. Zienicke, and ...
    • Article  

      Direct numerical simulation of particle laden flow in a human airway bifurcation model 

      Stylianou, F. S.; Sznitman, J.; Kassinos, Stavros C. (2016)
      During the delivery of inhaled medicines, and depending on the size distribution of the particles in the formulation, airway bifurcations are areas of preferential deposition. Previous studies of laminar flow through airway ...
    • Article  

      Dispersed-phase structural anisotropy in homogeneous magnetohydrodynamic turbulence at low magnetic Reynolds number 

      Rouson, D. I.; Kassinos, Stavros C.; Moulitsas, I.; Sarris, I. E.; Xu, X. (2008)
      A new tensor statistic, the dispersed-phase structure dimensionality Dp, is defined to describe the preferred orientation of clusters of discrete bodies. The evolution of Dp is calculated via direct numerical simulations ...
    • Article  

      Dispersed-phase structure in sheared MHD turbulence 

      Xu, X.; Rouson, D. W. I.; Kassinos, Stavros C.; Radhakrishnan, H. (2012)
      Direct numerical simulations are performed to examine particle dispersion in homogeneous turbulence subjected to mean shear and an externally applied magnetic field. We employ the Brucker et al. algorithm for simulating ...
    • Conference Object  

      Effect of turbulent pulsating flow around a near-wall submerged cylinder on the potential motion of bed and suspended loads 

      Fonias, E. N.; Grigoriadis, D. G. E. (International Society of Offshore and Polar Engineers, 2016)
      In the present work, the pulsating flow around a submerged cylinder close to the impermeable seabed is examined by means of Large Eddy Simulations (LES). A Reynolds number equal to Re = 5000 is considered, based on the ...
    • Article  

      Efficient treatment of complex geometries for large eddy simulations of turbulent flows 

      Grigoriadis, D. G. E.; Bartzis, J. G.; Goulas, A. (2004)
      Incompressible turbulent flow over a backward facing step at Reh=5100 is investigated by large eddy simulations (LES). The ratio of the oncoming boundary layer thickness δ to the step height h was set to 1.2. Additionally ...
    • Article  

      Flow development in compression of a finite amount of a Bingham plastic 

      Florides, G. C.; Alexandrou, Andreas N.; Georgiou, G. C. (2007)
      The flow and shape evolution during the compression of a finite amount of a Bingham plastic is investigated by means of numerical simulations. The problem relates to the popular compression test used for the rheological ...
    • Article  

      Flow instabilities of Herschel-Bulkley fluids 

      Alexandrou, Andreas N.; Menn, P. Le; Georgiou, G.; Entov, V. (2003)
      We investigate numerically the interactions of two-dimensional jets of Bingham plastic and Herschel-Bulkley fluids with a vertical surface at a distance from the die exit. This problem simulates the early stages of filling ...
    • Article  

      Inertial, viscous and yield stress effects in Bingham fluid filling of a 2-D cavity 

      Alexandrou, Andreas N.; Duc, E.; Entov, V. (2001)
      The present study concentrates on Bingham fluid filling of a 2-D cavity and examines the relative importance of inertial, viscous and yield stress effects on the filling profile. The results presented are obtained using ...
    • Article  

      Laminar free convection in a square enclosure driven by the Lorentz force 

      Sarris, I. E.; Grigoriadis, D. G. E.; Vlachos, N. S. (2010)
      A numerical study is presented of laminar free convection flow driven by magnetic forces. An external magnetic field with one spatially varying component is applied to an electrically conducting fluid in a square enclosure. ...
    • Article  

      Large Eddy Simulation of near-bed pipelines in oscillatory flow 

      Fonias, E. N.; Grigoriadis, D. G. E. (2018)
      A series of unsteady, three-dimensional numerical simulations of the incompressible, oscillatory flow around a near-bed pipeline is presented. A flow at Reynolds number equal to Reαo=20,000 with respect to the oscillatory ...
    • Article  

      Large-eddy simulations of the turbulent Hartmann flow close to the transitional regime 

      Sarris, I. E.; Kassinos, Stavros C.; Carati, D. (2007)
      A series of large-eddy simulations (LES) of turbulent and transitional channel flows of a conductive fluid under the effect of a uniform magnetic field applied in the wall-normal direction, usually referred to as Hartmann ...
    • Article  

      Large-eddy simulations of unidirectional water flow over dunes 

      Grigoriadis, D. G. E.; Balaras, E.; Dimas, A. A. (2009)
      The unidirectional, subcritical flow over fixed dunes is studied numerically using large-eddy simulation, while the immersed boundary method is implemented to incorporate the bed geometry. Results are presented for a typical ...
    • Article  

      Magnetohydrodynamic turbulence at moderate magnetic Reynolds number 

      Knaepen, B.; Kassinos, Stavros C.; Carati, D. (2004)
      We consider the case of homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field at low to moderate magnetic Reynolds numbers (by moderate we mean here values as high as 20). When ...
    • Article  

      MHD flow past a circular cylinder using the immersed boundary method 

      Grigoriadis, D. G. E.; Sarris, I. E.; Kassinos, Stavros C. (2010)
      The immersed boundary method (IB hereafter) is an efficient numerical methodology for treating purely hydrodynamic flows in geometrically complicated flow-domains. Recently Grigoriadis et als. [1] proposed an extension of ...