Our unit, the laboratory of Fluid Mechanics and Instabilities (LFMI) has the pleasure to announce the following seminar :
“A Numerical Investigation of the Fluid Mechanical Sewing Machine”
By Pierre-Thomas Brun
(Institut Jean le Rond d’Alembert/Lab. FAST, UPMC, Univ Paris-Sud, CNRS)
Friday 17th of February 2012 – 11:00 – Room MEB331
A thin thread of viscous ﬂuid falling onto a moving belt generates a surprising variety of patterns depending on the belt speed, fall height, ﬂow rate, and ﬂuid properties.
To understand the rich nonlinear dynamics of this system, we have developed a new numerical code for simulating unsteady viscous threads, based on a discrete description of the geometry and a variational formulation for the viscous stresses.
The code successfully reproduces all major features of the experimental state diagram of Morris et al. (Phys. Rev. E 2008). Fourier analysis of the motion of the thread’s contact point with the belt suggests a new classification of the observed patterns, and reveals that the system behaves as a nonlinear oscillator coupling the pendulum modes of the thread.
Authors : Pierre-Thomas Brun, Neil M. Ribe, Basile Audoly