Τμήμα Μηχανικών Μηχανολογίας και Κατασκευαστικής / Department of Mechanical and Manufacturing Engineering: Recent submissions

Now showing items 981-1000 of 1036

    • 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 ...
    • Conference Object  

      Particle-fluid dynamics under variable gravity conditions 

      Alexandrou, Andreas N.; Lemdiasov, R. A.; Gatsonis, N. A.; Jr, A. Sacco (Affiliation: Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, United StatesAffiliation: Northeastern University, Boston, MA 02111, United StatesCorrespondence Address: Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609, United States, 2000)
      Crystals grown from specially prepared liquid solutions have important industrial applications. The efficiency of these crystals is usually a function of their size. Therefore, during the synthesis of the crystals, it is ...
    • Article  

      Viscoplastic fluids: From theory to application (VPF2009), Limassol, Cyprus, 1-5 November, 2009 

      Alexandrou, Andreas N.; Georgiou, G. C.; Ovarlez, G. (2011)
    • Article  

      Shear rejuvenation, aging and shear banding in yield stress fluids 

      Alexandrou, Andreas N.; Constantinou, N.; Georgiou, G. (2009)
      The purpose of this work is to simulate shear rejuvenation and aging effects in shear thinning yield stress fluids in a typical rotational rheometer and to provide a common framework to describe the behavior of yield stress ...
    • 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  

      On the steady-state advancement of fingers and bubbles in a Hele-Shaw cell filled by a non-Newtonian fluid 

      Alexandrou, Andreas N.; Entov, V. (1997)
      The problem of steady-state propagation of a finger or a bubble of inviscid fluid through a Hele-Shaw cell filled by a viscous non-Newtonian, including visco-plastic (Bingham) fluid is addressed. Only flows symmetric ...
    • Article  

      An inverse approach to three‐dimensional solidification problems 

      Alexandrou, Andreas N.; Elden, R.; McConnell, J. (1993)
    • Conference Object  

      Rheological effects of strusture breakdown in semisolid slurries 

      Alexandrou, Andreas N.; Florides, G. C.; Georgiou, G. C.; Apelian, D. (Affiliation: Department of Mechanical and Industrial Engineering, University Cyprus, P.O.Box 20537, 1678 Nicosia, CyprusAffiliation: Department of Mathematics and Statistics, University of Cyprus, P.O.Box 20537, 1678 Nicosia, CyprusAffiliation: Metal Processing Institute, WPI, Worcester, MA, United StatesCorrespondence Address: Alexandrou, A.N.Department of Mechanical and Industrial Engineering, University Cyprus, P.O.Box 20537, 1678 Nicosia, Cyprus, 2004)
      An essential element for the integration of the semisolid metal (SSM) process in the production of complex commercial components is the availability of accurate mathematical and computational tools that could describe both ...
    • Conference Object  

      Sedimentation of heavy crystal particles under microgravity conditions 

      Alexandrou, Andreas N.; Gatsonis, N. A.; Shi, H.; Sacco, A. (American Institute of Aeronautics and Astronautics Inc, AIAA, 1998)
      Crystals grown from specially prepared liquid solutions have important industrial applications such as in biochemical processes, refining etc. The efficiency of these crystals is usually a function of their size. Therefore, ...
    • Article  

      Predictions of structure breakdown, buildup and shear banding in semisolid suspensions 

      Alexandrou, Andreas N.; Constantinos, N.; Georgiou, G. (2008)
      When SSM material is subjected to a sudden transient the rate of buildup (aging) is negligible compared to the rate of breakdown (shear rejuvenation). While this is generally true, due to prolonged processing or the geometry ...
    • Article  

      Squeeze flow of semi-solid slurries 

      Alexandrou, Andreas N.; Florides, G. C.; Georgiou, G. C. (2013)
      A standard method used to determine material properties of semi-solid slurries is the squeeze flow experiment
    • Article  

      Squeeze flow of thixotropic semisolid slurries 

      Alexandrou, Andreas N.; Florides, G. C.; Georgiou, G. (2014)
      An essential element for the integration of a semisolid process in the production of complex commercial components is the availability of accurate mathematical and computational tools that could describe both the rheological ...
    • Article  

      On bubble rising in a Hele-Shaw cell filled with a non-Newtonian fluid 

      Alexandrou, Andreas N.; Entov, V. M.; Kolganov, S. S.; Kolganova, N. V. (2004)
      The problem of a bubble rising due to buoyancy in a Hele-Shaw cell filled with a viscous fluid is a classical free-boundary problem first posed and solved by Saffman & Taylor. In fact, due to linearity of the flow equations ...
    • Conference Object  

      Thermo-fluid modeling of direct chill casting of metal alloys using an inverse finite element method 

      Alexandrou, Andreas N.; Battisti, T. (Publ by Computational Mechanics Inc, 1992)
      Direct chill (DC) casting is used extensively in the production of wrought nonferrous metals and alloys, particularly in the aluminum industry. For alloys, a semi-solid region known as the “mushy zone” and defined by the ...
    • Conference Object  

      Two-phase model for processing materials in semisolid state 

      Alexandrou, Andreas N.; Burgos, Gilmer R.; Entov, Vladimir (Affiliation: Worcester Polytechnic Inst, Worcester, United StatesCorrespondence Address: Alexandrou, Andreas N.Worcester Polytechnic Inst, Worcester, United States, 1998)
      The importance of processing of metal and metal matrix composites in semisolid state is increasing quite rapidly due to the distinct advantages it offers over similar methods of near-net-shape making. In this investigation ...
    • Conference Object  

      Thixotropy of semisolid metals 

      Alexandrou, Andreas N.; Burgos, G. R.; Entov, V. M. (Materials Research Society, 2000)
      Understanding the time-dependent flow behavior of metal alloys in semisolid state is essential for the further development of the process. In the present investigation, the thixotropic behavior of semisolid slurries is ...
    • Article  

      Breakup of a capillary bridge of suspensions 

      Alexandrou, Andreas N.; Bazilevskii, A. V.; Entov, V. M.; Rozhkov, A. N.; Sharaf, A. (2010)
      The breakup of liquid bridges under the action of capillary forces is used for studying the rheology of suspensions under stretching. The experiments were performed with suspensions of finegrained (3-30 μm) sand in glycerin ...
    • Article  

      Semisolid metal processing: A new paradigm in automotive part design 

      Alexandrou, Andreas N.; Burgos, G. R.; Entov, V. M. (2000)
      Processing of metal alloys in their mushy state represents a new trend in metal processing. The process produces components with low porosity, high crack resistance along with fine microstructure and mechanical properties ...
    • Conference Object  

      Injection molding of dilute and semi-dilute fiber suspensions 

      Alexandrou, Andreas N.; Ahmed, Alauddin (Publ by ASME, 1992)
      The focus of this paper is unsteady flow of semi-dilute fiber suspensions in complex geometries. These flows are typical of injection molding problems in which the raw material in granular form, usually plastic resin mixed ...
    • Article  

      An inverse finite element method with an application to extrusion with solidification 

      Alexandrou, Andreas N.; Anturkar, N. R.; Papanastasiou, T. C. (1989)
      The flow and solidification of planar jets are analysed by means of an efficient inverse isotherm finite element method. The method is based on a tessellation that is constructed by isotherms as characteristic co‐ordinate ...