Author(s): Bambang Winarta; Hitoshi Tanaka; Suntoyo
Linked Author(s): Hitoshi Tanaka
Keywords: Solitary wave; Boundary layer; Laminar solution; BSL k-ω model
Abstract: A method is proposed for generating the boundary layer flow beneath solitary wave. The method enables to generate the solitary wave boundary layer by facilitating a downstream movable gate which is controlled by a circular disc. The basic frame of circular disc design is mixed shape of half circle and half ellipse. Laboratory experimental is performed in a conduit water tunnel by using a Laser Doppler Veloci-meter (LDV). The experimental set-up consists of overflows head tank, downstream gate, flow velocity measurement device and conduit water tunnel. The conduit has a length 400cm, a width of 15cm and a height of 10cm. The overflow head tank maintains a constant pressure head and then flows along a conduit part. The downstream gate can rise up and drop down regularly in response to rotation of the disc connected with a motor. A LDV system, installed at 1.3m distance from the downstream end, is used for the velocity measurement at 17 points in the vertical direction. Experimental result of means velocity distribution is compared with a laminar solution and BSL k-ω model result, and good agreement is achieved for comparison with the latter. The velocity distribution of experiment result has negative value during the early stage of oscillatory motion, which is caused by the preceding periodical motion.