日本物理学会九州支部             九州大学理学研究科凝縮系科学専攻
         特別講演会                     第 2 回教室談話会



       Granular Flow in 2D Funnels and 3D Hourglasses 



     講師：   Dr. Peter Dimon
               The Niels Bohr Institute

     日時：   8月 26日 (木)  4:00 pm

     所：     九州大学 理学部 物理学科第一会議室(2154号室)


     アブストラクト:
     
     The behavior of granular flow depends in a sensitive way on the
     geometry.  If a 2D funnel has an opening angle greater than just two
     degrees, the flow is dense and steady, but if it is less than this,
     the flow is irregular and kinematic shock waves are present.  We have
     also examined how such a flow responds to an excitation.  For example,
     there is a critical acceleration necessary to maintain the flow, below
     which the balls jam (the well-known Muesli Effect).  We have also
     studied flows in 3D hourglasses where the counterflow of air is
     important and relaxation processes are observed.  Again, the geometry
     affects the behavior of the air/grain interface at the outlet.
     Moreover, if the air flow is controlled, there is a transition from
     relaxation to continuous flow.
     
     
     
     連絡先:
     
     中西　秀 (九大 理  092-642-2568)
     大同寛明（九工大 工 093-884-3421)
     
     
     この講演会は 日本物理学会九州支部と
     九州大学大学院理学研究科凝縮系科学専攻 共催です。