Begell House Inc.
Visualization of Mechanical Processes: An International Online Journal
VMP
3
4
2013
CFD-BASED VISULIZATION OF SINGLE-WAVE FLOW INTRACTING WITH A TRIANGULAR OBSTACLE
0
10.1615/VisMechProc.2016016329
Evgueni M.
Smirnov
Department of Aerodynamics,
St. Petersburg State Polytechnic University,
29, Polytechnitcheskaya Str.,
St. Petersburg, 195251, Russia
Alexander I.
Khrabry
Department of Hydro- and Aerodynamics at the Saint-Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg, 195251, Russia
Dmitri K.
Zaitsev
Department of Hydro- and Aerodynamics at the Saint-Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg, 195251, Russia
dam-break flow
computational fluid dynamics (CFD)
volume-of-fluid (VOF) method
flow-obstacle interaction
viscosity-induced separation
free-surface flow visualization
Dam-break turbulent flow interacting with a triangular obstacle is studied numerically. Two-dimensional (2D) and three-dimensional (3D) computations obtained by the volume-of-fluid method and based on previously published experiments have been carried out using an in-house unstructured-grid finite-volume Navier−Stokes code. Comprehensive visualization of the evolving flow structures in the near-obstacle region was performed. Videos and images illustrating 2D and 3D free-surface shapes as well as highly resolved velocity vector and wall friction patterns are presented. It has been established that the action of the bottom wall friction leads to the formation of one or two separation bubbles, depending on the flow development phase, and to the occurrence of associated hills at the free surface, which were observed in experimental photographs as well. The viscous effects at the confining-side walls of the channel result in a considerable 3D shape of the computed free surface, and its side view agrees with the experimental photographs much more than the result given by 2D solutions. Local-in-time separation of the flow from the side walls, predicted with the 3D formulation, is visualized as well.
EFFECT OF A DISSOLVED GAS ON THE CRITICAL HEAT FLUX DURING THE BOILING OF SUBCOOLED WATER
0
10.1615/VisMechProc.2016013833
Nikolay Viktorovich
Vasiliev
Joint Institute for High Temperatures, Russian Academy of Sciences, str. Izhorskaya 13, bld. 2, Moscow, 125412, Russia; Bauman Moscow State Technical University, str. 2-nd Baumanskaya 5, Moscow, 105005, Russia
Konstantin Alekseevich
Hodakov
Joint Institute for High Temperatures (JIHT) of the Russian Academy of Sciences, Izhorskaya Street, 13, Building 2, 125412, Moscow, Russia
Aleksey Yur'evich
Varaksin
Joint Institute for High Temperatures (JIHT) of the Russian Academy of Sciences, Izhorskaya Street, 13, Building 2, 125412, Moscow, Russia
burnout
subcooled water
dissolved gases
An experimental investigation of highly subcooled and degassed water saturated with carbon dioxide (up to ~0.3% in mass) was performed in a large volume. Fast video shooting of the processes was done (2 kHz). The dependencies of the critical heat flux density on the gas concentration during boiling of the subcooled water on the surface of an electrically heated capillary with a diameter of 1 mm in a large volume were obtained. Conclusions are drawn regarding the burnout mechanism during the boiling of subcooled water saturated with gas.