148 Computational Modelling in Hydraulic and Coastal Engineering
% Coastline boundary condition;
zn(nx)=z(nx)+sqrt(g*h(nx))*Dt/Dx*(z(nx-1)-z(nx));
for i=1:nx
zo(i)=z(i);
z(i)=zn(i);
hdepth(i)=z(i)+ho;
end
% Estimation of the wave height variance (h-rms)^2;
if k>nx2
for i=1:nx
zm(i)=zm(i)+(z(i)^2)/nx;
end
end
end
plot(1:nx,hdepth,'Linewidth',1.5)
hold on
plot(1:nx,bed,'m','LineWidth',2)
xlabel('Number of spatial steps x 2 [m]')
ylabel('Meters')
text(140,6.3,'Wave height [m]')
text(106,2,'Submerged breakwater')
text(20,2,'Time = nt*Dt [s]')
figure; plot(1:nx,zm,'','LineWidth',1.5)
hold on
xlabel('Number of spatial steps x 2 [m]')
ylabel('[m^2]')
text(20,15.2,'(h-rms)^2 [m^2]')
text(106,7,'Location of submerged breakwater')
text(140,11,'Time = nt*Dt [s]')
PROBLEM 6.2
Solve the same application by making the appropriate assumptions, modifying the computer code as needed and changing one or more of the input
data as suggested. In addition, you may need to change the total number of
time steps (code variable ‘nt’).
1. Change the bed friction to f bo = 0.1 s –1 and 0.01 s –1 , then run the simulations and comment on the results of the two cases.
2. Change the shape of the breakwater to an orthogonal triangle of base
28 m and height 3.0 m (right angle at the right-hand side of the base).
Conduct the simulation and compare the results with those of a rectangular breakwater of the same height and base.
3. Remove the breakwater and instead assume a seabed section at similar location and length having a bed friction coefficient of f bo = 0.1 s –1
and 1 s –1 . Conduct the simulations, then compare and discuss the
results of the two cases.