Experimental study of force, pressure, and fluid velocity on a simplified coastal building under tsunami bore impact
Autor: | Rodrigo Cienfuegos, Cyril Mokrani, Kuang-An Chang, James M. Kaihatu, Wei-Liang Chuang |
---|---|
Rok vydání: | 2020 |
Předmět: |
021110 strategic
defence & security studies Atmospheric Science Impact pressure 010504 meteorology & atmospheric sciences Turbulence Hydrostatic pressure Flow (psychology) 0211 other engineering and technologies 02 engineering and technology Mechanics 01 natural sciences law.invention Particle image velocimetry Flow velocity law Earth and Planetary Sciences (miscellaneous) Surge Hydrostatic equilibrium Geology 0105 earth and related environmental sciences Water Science and Technology |
Zdroj: | Natural Hazards. 103:1093-1120 |
ISSN: | 1573-0840 0921-030X |
Popis: | The present study experimentally investigated the flow kinematics and hydrodynamic pressures and forces on a simplified coastal building under tsunami bore impact. A rectangular structure sitting on a 1/10 sloping beach at four different headings, at 0°, 15°, 30° and 45°, was considered under bore impacts. The input wave condition was designed to generate a tsunami bore traveling at high speed on a sloping beach. The interaction between bore and structure (oriented at four different headings) was investigated using the nonintrusive bubble image velocimetry technique that enables the quantitative visualization of the full-field flow behavior. Simultaneous measurements of forces and pressures during the impacts were correlated with the measured flow velocities. As the tsunami bore is highly turbulent, ensemble averages from repeated tests were obtained for the investigation. To model the interaction, the validity of a dam break solution for a sloping bed as a suitable representation was examined, while the initial water depth was approximated using wave properties and calibrated with measured bore celerity. The study found that the profile of peak impact pressures is similar to a hydrostatic distribution for each heading, but one order of magnitude greater than the hydrostatic pressure. Similar linear distribution is also found in the correlation between peak impact pressure and angle of heading. By correlating the peak impact pressures with the impact velocity, the impact coefficient was estimated as 0.55. The measured pressures were further applied to model the surge force. By examining the peak surge forces against the heading angle, the lowest magnitude occurred when the structure was orientated at 30°. |
Databáze: | OpenAIRE |
Externí odkaz: |