title: Mach stem formation in reflection and focusing of weak shock acoustic pulses.
abstract: The aim of this study is to show the evidence of Mach stem formation for very weak shock waves with acoustic Mach numbers on the order of 10(-3) to 10(-2). Two representative cases are considered: reflection of shock pulses from a rigid surface and focusing of nonlinear acoustic beams. Reflection experiments are performed in air using spark-generated shock pulses. Shock fronts are visualized using a schlieren system. Both regular and irregular types of reflection are observed. Numerical simulations are performed to demonstrate the Mach stem formation in the focal region of periodic and pulsed nonlinear beams in water.
authors.affiliation: Department of Acoustics, Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119991, Russia masha@acs366.phys.msu.ru, vera@acs366.phys.msu.ru.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Karzova
authors.affiliation: Department of Acoustics, Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119991, Russia masha@acs366.phys.msu.ru, vera@acs366.phys.msu.ru.
authors.forename: Vera A
authors.initials: VA
authors.lastname: Khokhlova
authors.affiliation: Laboratoire de Mécanique des Fluides et d'Acoustique, Unité Mixte de Recherche 5509, Centre National de la Recherche Scientifique, Ecole Centrale de Lyon, Université Lyon I, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex, France edouard.salze@ec-lyon.fr, sebastien.ollivier@univ-lyon1.fr, philippe.blanc-benon@ec-lyon.fr.
authors.forename: Edouard
authors.initials: E
authors.lastname: Salze
authors.affiliation: Laboratoire de Mécanique des Fluides et d'Acoustique, Unité Mixte de Recherche 5509, Centre National de la Recherche Scientifique, Ecole Centrale de Lyon, Université Lyon I, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex, France edouard.salze@ec-lyon.fr, sebastien.ollivier@univ-lyon1.fr, philippe.blanc-benon@ec-lyon.fr.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Ollivier
authors.affiliation: Laboratoire de Mécanique des Fluides et d'Acoustique, Unité Mixte de Recherche 5509, Centre National de la Recherche Scientifique, Ecole Centrale de Lyon, Université Lyon I, 36 Avenue Guy de Collongue, F-69134 Ecully Cedex, France edouard.salze@ec-lyon.fr, sebastien.ollivier@univ-lyon1.fr, philippe.blanc-benon@ec-lyon.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Blanc-Benon