Please use this identifier to cite or link to this item:
|Title:||Experimental study on the solitary wave reflection along a straight sloped wall at oblique angle of incidence|
|Authors:||University of California, Berkeley. Wave Research Laboratory|
United States. Army. Office of the Chief of Engineers
Chen, T. C.
|Publisher:||United States, Beach Erosion Board|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical memorandum (United States. Beach Erosion Board) ; no. 124.|
From the Introduction: The reflection of a straight crested solitary wave from a vertical plane wall has been studied by P. H. Perroud (1). He observed that, when the angle of incidence i, which is the acute angle between the direction of wave travel and the lengthwise direction of the wall, was less than 20 degrees, there was no reflection, but at the point of contact with the wall, the wave bent to keep a right angle to the wall as shown in Figure 1a. As i was increased beyond 20 degrees a reflected wave of the Mach type, as shown in Figure 1b, appeared with a stem consisting of the bent portion which occured when i was less than 20 degrees. As the angle was further increased the stem shortened until at i = 45 degrees it disappeared, leaving the apex of the angle between the incident and reflected wave at the wall as shown in Figure 1c. In the present study, reflection from a sloping wall and some accompanying phenomena were studied. In the study of reflection, the angle of incidence was varied between zero and 90 degrees, and the slope angle ~ defined in Figure 2, between 20 and 150 degrees. Also in this case the depth of the water was uniform at 0.16 foot, the amplitude (a) to depth (h) ratio a/h, which is a measure of the size of a solitary wave, was 0.275. In the study of the breaking tendency and stability of the solitary wave itself, a/h, ~, and i were varied. A solitary wave was generated in a ripple tank of 20 feet x 44.5 inches x 5 inches by giving the water and impulsive push by means of a paddle which was activated by a dropping weight. By setting the wave at a predetermined height, solitary waves of the same size could be generated with sufficient accuracy for this experiment. The wave height was measured by parallel wire wave probes together with amplifiers and a Brush recorder with two channels. Reflection patterns were obtained by means of a spark light which came from underneath the water through the disturbed water to a photosensitive paper placed above the water surface at a height determined by focusing the image of the water disturbance on the paper. When the wave reached some predetermined position, the spark was produced by means of a relay circuit. Note: The symbol ~ is used to indicate the presence of a scientific or mathematical symbol that could not be rendered by this system's character set. The downloaded will have the missing symbols.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Technical Memorandum|
Files in This Item:
|BEB-TM-124.pdf||4.37 MB||Adobe PDF|