13,784 research outputs found
Quantum field theory approach to the vacuum replica in QCD
Quantum field theory is used to describe the contribution of possible new QCD
vacuum replica to hadronic processes. This sigma-like new state has been
recently shown to be likely to appear for any realistic four-quark interaction
kernel as a consequence of chiral symmetry. The local operator creating the
replica vacuum state is constructed explicitly. Applications to physical
processes are outlined.Comment: LaTeX2e, 2 EPS figures, uses ws-procs9x6 (included) and epsfig
classes, Talk given at the conference "Quark Confinement and the Hadron
Spectrum V", 10-14 September 2002, Gargnano, Italy, to appear in Proceeding
DNS of Laminar to Turbulent Transition on NACA 0012 Airfoil with Sand Grain Roughness
The Lattice-Boltzmann-based solver PowerFLOW is used to perform direct numerical simulations of the transitional flow over an airfoil at Reynolds number equal to 0.657 million. The leading edge of the airfoil is covered with sand particles, represented by polyhedra, to mimic the grit used in experiments. The sensitivity of the laminar to turbulent transition to the size of these particles, grid resolution, spanwise length is evaluated and rectangular trips are also tested
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