CERC UNIDIRECTIONAL SPECTRAL INCIDENCE/REFLECTION ANALYSIS 



6 FT SCOUR TESTS, SPECTRAL, ST14W05A 



OFFSHORE PROBE = DATA CHANNEL 



CENTER PROBE = DATA CHANNEL 



ANALYSIS DATE 5-OCT-89 

 ANALYSIS TIME 1356 

 NEARSHORE PROBE = DATA CHANNEL 6 



WATER DEPTH = 2.200 DETREND MODE - 1 (MEAN REMOVED) 

 GRAVITY = 32.20 WINDOW MODE = 1 (COSINE SQUARED) 

 TIME STEP - 0.5000E-01 NUMBER OF TIME STEPS ANALYZED = 



PLOTTED RESULTS? YES 

 10% OF RECORD TAPERED AT EACH END 

 3200 



MEAN UPCROSSING ANALYSIS RESULTS (AVERAGES OF RESULTS FROM THREE PROBES) : 



ETABAR = -0.1574E-01 

 ETABMS = 0.1660 

 ETASD = 0.1661 

 HMAX = 0.9430 



ETAMAX = 0.6644 

 ETAMIN - -0.3759 

 HEAR = 0.4181 

 TBAR = 1.938 



H 1/3 = 0.6492 



T 1/3 - 2.128 



RHOHH = 0.5083 



RHOHT = 0.3374 



MEAN DOWNCROSSING ANALYSIS RESULTS (AVERAGES OF RESULTS FROM THREE PROBES) : 



ETABAR = -0.1574E-01 

 ETARMS = 0.1660 

 ETASD = 0.1661 

 HMAX = 0.9383 



ETAMAX 

 ETAMIN 

 HBAR 

 TBAR 



0.6644 



-0.3759 



0.4186 



1.931 



H 1/3 = 0.6497 



T 1/3 - 2.082 



RHOHH = 0.4490 



RHOHT = 0.3451 



DETRENDING RESULTS: 



(VALUES DEPEND ON 

 DETREND MODE IM- 

 POSED) 



OFFSHORE 



CENTER 



NEARSHORE 



-0.1542E-01 

 -0.1591E-01 

 -0.1590E-01 



O.OOOOE+00 O.OOOOE+00 

 O.OOOOE+00 O.OOOOE+00 

 O.OOOOE+00 O.OOOOE+00 



PARAMETERS OF INCIDENT SPECTRUM: 



HMO = 0.6661 



PARAMETERS OF REFLECTED SPECTRUM: 



MEAN REFLECTION COEFFICIENT 



EMO = 

 EMI = 

 EM2 - 

 T02 = 



.2773E-01 

 .1444E-01 

 .8291E-02 

 1.829 



EMO = 0.2014E-02 



EMI = 0.1202E-02 



EM2 - 0.9067E-03 



T02 - 1.490 



FPS = 

 TPS = 

 FPD = 

 TPD = 



FPS = 

 TPS = 

 FPD = 

 TPD = 



.4500 

 2.222 

 .4344 

 2.302 



0.4125 

 2.424 



0.4125 

 2.424 



Figure A4. Example of three-gage average values and reflection analysis (nearshore array) 



monochromatic test. The upper record was obtained at the offshore array, while the lower record was 

 measured at the nearshore array. The nonuniformity in the regular wave field did not impact the outcome 

 of the experiments because it can be assumed that similar effects occurred in the large-scale experiments. 



9. This nonuniformity in regular waves can, however, impact the results from the wave analysis 

 program. Usually, a portion of the record containing between 30 to 50 waves was selected for analysis. 

 Depending upon which section of record was analyzed, it was possible to obtain values for the statistical 

 wave height parameters that showed considerable variation. For the most part, the same region of record 

 was analyzed, but this was not always the case, and variations between nearshore averages seen in the 

 Appendix B results can usually be attributed to this cause. 



10. Variations in nearshore wave statistics between experiments that are claimed to have identical 

 wave input may give the impression that the experiments were not the same, but the important point to 

 remember is that these cases all had the same input wave board signal. Examination of the offshore wave 

 statistics between experiments gives a better indication of the similarity of regular wave input. 



11. The authors advise anyone who may use these experimental profile evolution results to validate 

 numerical models that it would be better to drive the numerical model with the measured offshore wave 



A5 



