PHYSICS/BK21 SEMINA[09..07.03]
관련링크
본문
"
“Onsager Principle and
Nanoscale Hydrodynamics”
♦Speaker : Prof. Ping Sheng (Hong Kong University)
♦Place : Physics Seminar Room (Science Bldg, 3-201)
♦Date & Time : July 3 (Fri), 15:00 ~ 16:00 pm
Abstract
It is probably not a well-known fact that up until recently, continuum hydrodynamics can not accurately
model immiscible flows at the nanoscale. The problem is not with the Navier-Stokes equation, which
must be true, but lies in the hydrodynamic boundary condition, which for the past century has been
held to be no-slip at the fluid-solid interface. In this talk, the history of the hydrodynamic boundary
condition and its associated classic problem of moving contact line will be introduced in some detail.
Here the contact line denotes the intersection of the immiscible fluid-fluid interface with the solid wall,
and when one fluid displaces the other, the contact line moves along the solid wall. Almost half a
century ago it was already recognized that the moving contact line will lead to infinite viscous dissipation
if one uses the no-slip hydrodynamic boundary condition. We show that by using the Onsager variational
principle, which can be easily derived from basic statistical mechanic principles, one can simultaneously
derive the Navier-Stokes equation and its related boundary conditions at the fluid-solid interface.
The resulting continuum hydrodynamic system, with the revised hydrodynamic boundary conditions, is
shown for the first time to quantitatively reproduce molecular dynamic simulation results at the nanoscale.
Implications of this result for nanoscale hydrodynamics, together with its complementary relation to the
kinetic theory of fluids, will be shown by short movies as well as discussed.
Contact Person : Prof. Wokyung Sung(054-279-2061, wsung@postech.ac.kr)
"
“Onsager Principle and
Nanoscale Hydrodynamics”
♦Speaker : Prof. Ping Sheng (Hong Kong University)
♦Place : Physics Seminar Room (Science Bldg, 3-201)
♦Date & Time : July 3 (Fri), 15:00 ~ 16:00 pm
Abstract
It is probably not a well-known fact that up until recently, continuum hydrodynamics can not accurately
model immiscible flows at the nanoscale. The problem is not with the Navier-Stokes equation, which
must be true, but lies in the hydrodynamic boundary condition, which for the past century has been
held to be no-slip at the fluid-solid interface. In this talk, the history of the hydrodynamic boundary
condition and its associated classic problem of moving contact line will be introduced in some detail.
Here the contact line denotes the intersection of the immiscible fluid-fluid interface with the solid wall,
and when one fluid displaces the other, the contact line moves along the solid wall. Almost half a
century ago it was already recognized that the moving contact line will lead to infinite viscous dissipation
if one uses the no-slip hydrodynamic boundary condition. We show that by using the Onsager variational
principle, which can be easily derived from basic statistical mechanic principles, one can simultaneously
derive the Navier-Stokes equation and its related boundary conditions at the fluid-solid interface.
The resulting continuum hydrodynamic system, with the revised hydrodynamic boundary conditions, is
shown for the first time to quantitatively reproduce molecular dynamic simulation results at the nanoscale.
Implications of this result for nanoscale hydrodynamics, together with its complementary relation to the
kinetic theory of fluids, will be shown by short movies as well as discussed.
Contact Person : Prof. Wokyung Sung(054-279-2061, wsung@postech.ac.kr)
"