Particle acceleration and pressure gradient in a solitary wave traveling over a horizontal bed
| Autor: | Chang Lin, James Yang, Ming-Jer Kao, Shih-Chun Hsieh, Juan-Ming Yuan, Rajkumar V. Raikar |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Physics General Physics and Astronomy 02 engineering and technology Mechanics 021001 nanoscience & nanotechnology Gravitational acceleration 01 natural sciences lcsh:QC1-999 Physics::Fluid Dynamics Adverse pressure gradient Particle acceleration Acceleration Particle image velocimetry 0103 physical sciences Crest 0210 nano-technology lcsh:Physics Pressure gradient Dimensionless quantity |
| Zdroj: | AIP Advances, Vol 10, Iss 11, Pp 115210-115210-15 (2020) |
| ISSN: | 2158-3226 |
| DOI: | 10.1063/5.0028537 |
| Popis: | This study presents experimental data on the hydrodynamic features of a nonlinear solitary wave of height H0 = 2.9 cm propagating over a horizontal bed in otherwise still water depth h0 = 8.0 cm. High-speed particle image velocimetry is used to quantify the local and convective particle accelerations and pressure gradients under the solitary wave. It is found that the magnitudes of the horizontal and vertical particle local accelerations are invariably larger than their convective counterparts, highlighting the important contribution of local acceleration to the pressure gradient in a solitary wave. The dimensionless pressure gradient in the horizontal direction is favorable, zero, and adverse for time before, at, and after the wave crest passes the section of interest. The dimensionless adverse pressure gradient exhibits a maximum for the dimensionless time T[=t(g/h0)1/2, where g is the gravitational acceleration and t is the time with respect to the crest passing the section] = 1.39, at which the dimensionless local acceleration has a negative maximum. Subsequently, flow reversal takes place above the bed surface. The relationship is elucidated between flow reversal at the bed surface and the evolution of the adverse pressure gradient in the near-bed zone, where uniform horizontal/free stream velocity exists. |
| Databáze: | OpenAIRE |
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