CHAPTER 4 

 EXPERIMENTAL VERIFICATION OF THEORY 



Again, all theory before 1967 which has been thoroughly discussed by 

 Galvin (1967) has been omitted in this report. Results of comparisons 

 between laboratory and field measurements and theory as original presented 

 in the literature are reviewed. No new analysis of the available data baae 

 is attempted. Only those equations from Chapter 3 that have experimental 

 backing or are seriously questioned are repeated in this chapter. 



I. WAVE SETDOWN AND SETUP 



1 . Regular Linear Waves . 



Some classic results of MWL change as determined in a 0.5-meter-wide 

 by 0. 75-meter-deep by 40-meter-long wave flume by Bowen, Inman, and Simmons 

 (1968) are shown in Figure 46. The wave height in deep water was 6.45 

 centimeters and the beach slope 1 on 12. For normal wave incidence on a 

 plane beach, wave setdown is shown to match the theory given by equation 

 (30), except near the breaker line. Wave setup was found to be almost 

 linear over the entire surf zone and proportional to the beach slope as 

 expected from equation (35), repeated here 



= K tan 





dn 

 dx 





1 





1 -f 



8/3y2 



letting 









K = 



1 

 tan 



I ^"^max 



- n^)/x^ (153) 



K versus y ^s plotted in Figure 47. Included are data from Putnam, Munk 

 and Traylor (1949) for other slopes and the agreement was characterized as 

 ". . . quite good." 



Gourlay (1978) reanalyzed the Bowen, _Inman, and Simmons data and con- 

 cluded that values of maximum wave setup '^^^-^ in equation (153) were over- 

 estimated (see App. A4.43 in Gourlay, 1978) due to inclusion of wave runup 

 effects. Both plunging- and spilling- type breakers were produced in the 

 tests of Bowen, Inman, and Simmons (1968). 



Similar results were obtained by Smith (1974) for breaking waves of 

 the same types. Gourlay (1978) also adjusted these data to account for 

 total water volume and include a discussion of the results. 



157 



