Experiment

Graphic showing flat plate experimental set-up.

Results are presented from a towing-tank experiment of 3D separation and free-surface turbulence to provide detailed documentation of the flow appropriate both for explicating the flow physics and validating computational methods.  The model is NACA24 which is a 1.2 m chord length, vertical, surface-piercing hydrofoil.  The data includes far and near field wave elevations, surface pressures, and wave profiles on the hull at three Froude numbers (Fr = 0.19, 0.37, 0.55).

Data, Equipment, and Conditions

Data Equipment Fr Locations
Boundary layer and wake flow field 2D LDV 0.13 x / L = 0.5, y / L = 0-0.03, z / L = -0.125-0
x / L = 1.25, y / L = 0-0.06 z / L = -0.125-0

 

Sample Image

The experimental setup for the flat plate tests shows a medium steepness Stokes wave on the plate at Fr = 0.4 (above). The submerged horizontal hydrofoil (white) is shown upstream of the vertical, surface-piercing flat plate (black), and the starboard flow straightener is shown on the far right side of the photo.

Photo showing the experimental setup for the flat plate tests

Sample Data

Graphic showing sample data

Contours of boundary layer x / L = 0.5 and wake x / L = 1.25 axial velocity (U) measurements for Fr = 0.13 (above).

References:

Stern, F., Parthasarathy, R., Huang, H.P., and Longo, J., (1995), “Effects of waves and free surface on turbulence in the boundary layer of a surface-piercing flat plate,” In: ASME fluids engineering Conf. Symp. on free-surface turbulence, Edited by E. Rood and J. Katz, American Society of Mechanical Engineers, New York, FED-Vol. 181, p. 37.

Stern, F., Hwang, W.S., and Jaw, S.Y., (1989), “Effects of waves on the boundary layer of a surface-piercing flat plate: experiment and theory,” Journal of Ship Research, Vol. 33, pp. 63.

Stern F., Choi, J.E., and Hwang, W.S., (1993), “Effects of waves on the wake of a surface-piercing flat plate: experiment and theory,” Journal of Ship Research, Vol. 37, pp. 102.

Longo, J., Huang, H.P., and Stern, F., (1998), “Solid/free-surface juncture boundary layer and wake,” Experiments in Fluids, Vol. 25, pp. 283–297.

Kang, D.H., Longo, J., Marquardt, M., and Stern, F., (2008), “Solid/free-surface juncture boundary layer and wake with waves,” Proc. 27th ONR Symposium on Naval Hydrodynamics, Seoul, Korea, 2008.