maximum stream velocity is about 2m/sec. The water depth is 0.8m. The reference velocity was measured by a pitot tube in the middle portion of experimental section and the pitot tube was set at the depth of 0.3m.
The acrylic flat plate had the size of 45cm length, 15cm width, 10mm thickness and holes of 6 × 16 for the purpose of measuring the pressure distribution on a plate as shown in Fig.2. The pressure distribution on the plate was measured by the pressure gauge. The plate was installed with the wetted chord length of 6cm and the attack angle of 5 degrees to the flow of the circulating water channel.
Fig.2 A planing flat plate and pressure measurements
Fig.3 shows waves generated by a planing flat plate. The wave profiles are clear, but the wave elevations are very low for the reason of small attack angle of a plate. Therefore, the detailed and precise measurements of flow field around a plate of small size with the small attack angle were very difficult, and these measurements could not be performed. The wave profiles were measured by the servo-type wave gauge.
Fig.3 Waves generated by a planing plate with small attack angle
The schematic wave pattern is shown in Fig.4 and consists of four waves which are bow divergent waves, stern divergent waves, triangle waves and stern cross waves. As to their names, the last two are named tentatively.
Fig.4 Schematic wave pattern
3. BASIC EQUATIONS
The basic equations are the continuity equation and the Navier-Stokes equations for incompressible fluid. The Navier-Stokes equations can be written in the physical Cartesian coordinates (x,y,z) as follows,
The Cartesian coordinates (x,y,z) is taken as shown in Fig.5 and its origin of the coordinate is on the intersection of center line and leading edge of plate in still water, the x-axis horizontal along the downward direction of flow, the y-axis horizontal along the right-handed side on the leading edge, and the z-axis vertically upwards. φ is the pressure defined by φ＝P+z/Fn2. Non-dimensional continuity equation is
