LABORATORY STUDY OF WAVE ENERGY LOSSES BY BOTTOM FRICTION AND PERCOLATION
Abstract
Tests were conducted to check theories developed by Putnam and Johnson (Trans. Am. Geophys. Union 30: nos. 1 and 3, 1949). The experimental data were obtained in a steel-plate wave flume equipped with a plywood splitter wall which divided the tank longitudinally. A plywood floor installed on one side was used for bottom-friction and percolation control. Friction tests with natural ripples indicated that the energy loss depends upon the ripple-formation stage for the particular wave period and height. The energy loss increased to a maximum rate during ripple formation and then decreased nearly to the initial value after the completion of the ripple formation. The maximum rate of frictional loss agreed well with the theoretical value. The theoretical equations were unsatisfactory for the determination of bottom-friction losses for artificial ripples dissimilar to natural ripples. Reasonable agreement with test and theoretical values of wave-height loss resulted with artificial ripples similar to natural ripples; the friction losses increased with decreased ratios of the ripple pitch to height. The experimental percolation energy losses were far less than the theoretical values; correction factors of 4 to 10 were needed to obtain reasonable agreement. Sand sizes larger than 2 mm resulted in very large percolation losses, while losses for low-permeability sands were insignificant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1953
- Accession Number
- AD0011564
Entities
People
- John C. Fairchild
- Rudolph P. Savage
Organizations
- Coastal Engineering Research Center