An Experimental Study on the Interaction between Oscillatory Flow and Idealized Porous Bed

Abstract

Shigematsu, Sota Nakajo, and Yuya Okada, 2018. An Experimental Study on the Interaction between Oscillatory Flow and Idealized Porous Bed. In: Shim, J.S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 981–985. Coconut Creek (Florida), ISSN 0749-0208.The microscopic structures of over and inside flow of a porous medium placed in oscillatory flow was measured by the Particle Tracking Velocimetry with the refractive index matching method in order to investigate interaction between them. The strong shear flow was observed over the surface of the porous medium and the thickness of shear flow varied with the phase of the oscillatory flow. It was found that the thickness of non-dimensional shear flow was almost constant and that it did not depend on the Reynolds number. It was found that the thickness of non-dimensional shear flow was almost constant and it independented with the Reynolds number. Besides, it was also found that the phase difference between flows over and inside the porous bed occurred. The characteristics of the spatial variance of velocity components were shown in detail with the time phase variance. Further, the flow properties around the particle constitutes porous body were measured and investigated in detail.