SUBROUTINE INTER - Internal wave transmission and reflection coefficients 

 for the equivalent breakwater foimd in EQBW are solved in this routine. MW 

 equations (57) and (37) are solved implicitly using R^ = 170 and interpolation 

 of MW Figures 2 and 3, when nkl is greater than 0.1. If nkl is greater 

 than 0.9 the coefficients cannot be solved, so another equivalent breakwater 

 with smaller reference diameter stone is determined. 



SUBROUTINE EQBW - This routine determines the rectangular breakwater 

 corresponding to the multilayered trapezoidal breakwater using the methods 

 described in MW Section IV, 2. The initial reference diameter is taken as one- 

 half the armor diameter and reference porosity is defined as 0.435. 



SUBROUTINE LENGTH - Finds the relative depth given the ratio of water depth 

 to deepwater wavelength. 



1, Program Use . The following steps are required to use the program MADSEN: 



(a) Assign each of the materials used in the various layers of the 

 breakwater a consecutive number making the armor "material number 1." 

 Determine the diameter of each material from 



^50 



(^)' 



where W50 is the median weight and y the specific weight. Also 

 estimate the material porosity. 



(b) Divide the breakwater into horizontal layers. A new layer 

 occurs any time there is a change vertically in any material type of 

 slope (see Fig. G-2 for an example problem). Make the layer next to 

 the seabed "layer number 1." Find the thickness of each layer and 

 determine the average horizontal length of each material in each layer. 

 Remove the outer layer of armor from the seaward face of the breakwater 

 before making length calculations, because energy dissipation on the 

 front face is determined separately in the program. 



(c) Estimate the kinematic viscosity of water as a function of 

 water temperature (Table G-3) . 



(d) Estimate breakwater water runup parameters, a and b. At 

 the present time the values of a = 0.692 and b = 0.504 are recommended 

 based on the laboratory data of Hudson (1958) . 



(e) Put the information into the required input format (Table G-4) . 

 Input cards for the example breakwater (Fig. G-2) are shown in Table G-5. 



(f) Sample output for the example problem is shown in Table G-6. 



2. Computer Program . A listing of the computer program MADSEN is given in 

 Table G-7. 



79 



