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On the basis of these considerations, the above-mentioned sensitivity parameters were chosen in this study. As a result, a total of nine parameters were investigated by applying physical feasible ranges for each parameter. The calculated deposited amount of each sensitivity simulation was compared to the simulation results of a reference case computation and to the amount of deposits calculated from measurements (given in Table 3). The reference case computations were done on the coarser gird to save computational time. The definitions of the input parameters for the reference case are given in Table 2.

Table 2

Settings of the input parameters for the reference case

Numerical parameters 
 Grid resolution Coarser grid (100 × 40 × 10) 
 Time step Varying time step with an average time step of 10,000 seconds 
 Discretization scheme Second-order scheme 
 Active layer thickness 10 cm 
Physical parameters 
 Initial grain size distribution See Table 1  
 Roughness 2 cm 
 Bed load transport formula van Rijn (1984b)  
Parameters correlated to cohesive sediments 
 Fall velocity Zanke (1977), see Table 1  
 Critical shear stress for bed particles Shields (1936)  
Numerical parameters 
 Grid resolution Coarser grid (100 × 40 × 10) 
 Time step Varying time step with an average time step of 10,000 seconds 
 Discretization scheme Second-order scheme 
 Active layer thickness 10 cm 
Physical parameters 
 Initial grain size distribution See Table 1  
 Roughness 2 cm 
 Bed load transport formula van Rijn (1984b)  
Parameters correlated to cohesive sediments 
 Fall velocity Zanke (1977), see Table 1  
 Critical shear stress for bed particles Shields (1936)  
Table 3

Sediment deposits in intake channel

MethodDeposits [m³]Deviation, reference [%]Deviation, measured [%]
Measured 51,000 −10 0.0 
Computed, reference case 56,850 0.0 11 
Computed, 300 seconds fixed time step (30,000 time steps) 54,721 −3.7 7.3 
Computed, fine grid and 300 seconds fixed time step 50,031 −14 −1.9 
Computed, with initial bed grain size distribution from reference case 56,239 −1.1 10 
Computed, fall velocities from Winterwerp formula for 3 finest fractions 45,305 −20 −13 
Computed, 5 × larger fall velocities for 3 finest fractions 83,961 48 65 
Computed, roughness from 2 to 5 cm 47,769 –16 −6.7 
Computed, roughness from 2 cm to a value calculated using the van Rijn formula in equation (1) 51,947 –8.6 1.8 
Computed, active layer thickness from 0.1 to 0.2 m 57,635 1.4 13 
Computed, active layer thickness from 0.1 to 0.02 m 57,144 0.5 12 
Computed, Engelund–Hansen formula 46,140 −19 −11 
Computed, van Rijn suspended load formula only 60,458 6.3 19 
Computed, first-order scheme instead of second-order scheme 59,616 4.9 17 
Computed, cohesion equivalent to 1 Pa on 4 finest fractions 70,395 24 38 
Computed, cohesion equivalent to 0.1 Pa on 4 finest fractions 67,022 18 31 
Computed, cohesion equivalent to 0.01 Pa on 4 finest fractions 58,264 2.5 14 
MethodDeposits [m³]Deviation, reference [%]Deviation, measured [%]
Measured 51,000 −10 0.0 
Computed, reference case 56,850 0.0 11 
Computed, 300 seconds fixed time step (30,000 time steps) 54,721 −3.7 7.3 
Computed, fine grid and 300 seconds fixed time step 50,031 −14 −1.9 
Computed, with initial bed grain size distribution from reference case 56,239 −1.1 10 
Computed, fall velocities from Winterwerp formula for 3 finest fractions 45,305 −20 −13 
Computed, 5 × larger fall velocities for 3 finest fractions 83,961 48 65 
Computed, roughness from 2 to 5 cm 47,769 –16 −6.7 
Computed, roughness from 2 cm to a value calculated using the van Rijn formula in equation (1) 51,947 –8.6 1.8 
Computed, active layer thickness from 0.1 to 0.2 m 57,635 1.4 13 
Computed, active layer thickness from 0.1 to 0.02 m 57,144 0.5 12 
Computed, Engelund–Hansen formula 46,140 −19 −11 
Computed, van Rijn suspended load formula only 60,458 6.3 19 
Computed, first-order scheme instead of second-order scheme 59,616 4.9 17 
Computed, cohesion equivalent to 1 Pa on 4 finest fractions 70,395 24 38 
Computed, cohesion equivalent to 0.1 Pa on 4 finest fractions 67,022 18 31 
Computed, cohesion equivalent to 0.01 Pa on 4 finest fractions 58,264 2.5 14 

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