slope of the structure, water depth, wave height and period, and the 

 kinematic viscosity of water (Table 2) . To use this method, waves 

 should have 



d ^ 1.25 r^-, 



L VHj cot2 e 



where L is local wavelength. 



Table 2. Kinematic viscosity of water. 



Water temperature 



Kinematic viscosity of water 



(°C) 



(mVs) 



0° 



0.0000018 



10° 



0.0000013 



20° 



0.0000010 



30° 



0.0000008 



The Madsen and White model was tested against laboratory data for 

 permeable breakwaters (Seelig, in preparation, 1979)7 and was shown to 

 give useful estimates for both monochromatic and irregular waves. For 

 irregular wave conditions, the wave input to the program should be the 

 mean wave height and period of peak energy density. A few tests with 

 breaking waves suggest that the prediction method can also be used with 

 breaking waves. The Madsen and White model appears to effectively 

 account for breaking wave energy losses, although it does not explicitly 

 include breaking. Tests of breakwaters armored with doles units suggest 

 that the program can also be used for artificial armor units. Compari- 

 son with laboratory data shows that the model gives the best predictions 

 for shallow-water waves. Predictions of transmission coefficients tend 

 to be conservative for transitional or deepwater waves. Refer to Seelig 

 (in preparation, 1979)7 or Madsen and White (1976)8 for more information. 

 Figure 2 shows a comparison between wave transmission coefficients ob- 

 served in a laboratory model and predicted using the methods described 

 in this CETA. 



IV. EXAMPLE 



Use of the computer program (MADSEN) in the Appendix can best be 

 illustrated by an example. The format of required input information is 

 given in Table 3. Any number of breakwater geometries, water depths or 

 wave conditions can be analyzed in a single run. The first 53 cards are 

 a standard deck of look-up (input) tables (see Table A-1); card type 1 

 provides the number of breakwater configurations or water depths to 

 analyze. Card types 2 to 6 give required input information for each 

 breakwater of interest; however, a separate set of these card types is 

 required when the breakwater geometry or water depth is changed. 



7SEELIG, W.N. , op. cit. , p. 7. 



^MADSEN, O.S., and WHITE, S.M., op. cit. 



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