RiverlabThis website provides the platform for the availability and continuous development of the process-based, hydrodynamic and morphological model environment. It is based on the Delft3D-FM (Flexible mesh) software. Available is the software for 1D, 2D and 3D modelling. Some example-models are available.https://oss.deltares.nl/c/message_boards/find_category?p_l_id=3228466&mbCategoryId=02021-05-16T10:04:37Z2021-05-16T10:04:37ZRE: Bars in riversH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=36748112020-12-11T10:20:33Z2020-12-11T10:20:33ZThanks a lot for your help and for Alessandra Crosato who contacted me and answered my questions.H A2020-12-11T10:20:33ZRE: Bars in riversH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=36736612020-12-10T20:20:15Z2020-12-10T19:58:37ZThanks a lot for your help. I appreciate that. My study focuses on the large-scale impact of installing bridge piers on river morphology with different scenarios of piers installation and different cases. First, I want to simulate the river without any piers and run a simulation for the case with no piers, let the bed developed and bar forms (periodic bars (free or steady)) until it reaches equilibrium so that I could compare the differences afterward when I install piers in the next scenarios. what I expected that depending on the width to depth ratio and other parameters like discharge, friction, and bed slope I will witness a bar mode as calculated from the formula and after a while, it would reach the equilibrium state. but the fact is that it did not reach the equilibrium and the bars are disappearing as shown in the following figures. The figures below are the output of the simulation after 10, 20, 30, 50, and 60 years successively. what do you think is there something wrong with my approach or my simulation?H A2020-12-10T19:58:37ZRE: Bars in riversH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=35938812020-12-06T01:21:44Z2020-12-06T01:21:44Z[MorphologyFileInformation]<br /> FileCreatedBy = Delft3D FLOW-GUI, Version: 3.59.01.57433 <br /> FileCreationDate = Wed Dec 02 2020, 23:37:24 <br /> FileVersion = 02.00 <br />[Morphology]<br /> EpsPar = false Vertical mixing distribution according to van Rijn (overrules k-epsilon model)<br /> IopKCW = 1 Flag for determining Rc and Rw<br /> RDC = 0.01 [m] Current related roughness height (only used if IopKCW <> 1)<br /> RDW = 0.02 [m] Wave related roughness height (only used if IopKCW <> 1)<br /> MorFac = 1.0000000e+000 [-] Morphological scale factor<br /> MorStt = 7.2000000e+002 [min] Spin-up interval from TStart till start of morphological changes<br /> Thresh = 5.0000001e-002 [m] Threshold sediment thickness for transport and erosion reduction<br /> MorUpd = true Update bathymetry during FLOW simulation<br /> EqmBc = true Equilibrium sand concentration profile at inflow boundaries<br /> DensIn = false Include effect of sediment concentration on fluid density<br /> AksFac = 1.0000000e+000 [-] van Rijn's reference height = AKSFAC * KS<br /> RWave = 2.0000000e+000 [-] Wave related roughness = RWAVE * estimated ripple height. Van Rijn Recommends range 1-3<br /> AlfaBs = 1.0000000e+000 [-] Streamwise bed gradient factor for bed load transport<br /> Sus = 1.0000000e+000 [-] Multiplication factor for suspended sediment reference concentration<br /> Bed = 1.0000000e+000 [-] Multiplication factor for bed-load transport vector magnitude<br /> SusW = 1.0000000e+000 [-] Wave-related suspended sed. transport factor<br /> BedW = 1.0000000e+000 [-] Wave-related bed-load sed. transport factor<br /> SedThr = 1.0000000e-001 [m] Minimum water depth for sediment computations<br /> ThetSD = 0.0000000e+000 [-] Factor for erosion of adjacent dry cells<br /> HMaxTH = 1.5000000e+000 [m] Max depth for variable THETSD. Set < SEDTHR to use global value only<br /> FWFac = 1.0000000e+000 [-] Vertical mixing distribution according to van Rijn (overrules k-epsilon model)<br /> Espir = 0.5 [-] Calibration factor spiral flow<br /> ISlope = 3 [-] Flag for bed slope effect<br /> AShld = 9.0 [-] Bed slope parameter Koch & Flokstra<br /> BShld = 0.5 [-] Bed slope parameter Koch & Flokstra<br /> CShld = 0.3 [-] Bed slope parameter Koch & Flokstra<br /> DShld = 1 [-] Bed slope parameter Koch & Flokstra<br />[Numerics]<br /> MaximumWaterdepth = false<br /> LaterallyAveragedBedload = false<br /> UpwindBedload = trueH A2020-12-06T01:21:44ZRE: Bars in riversH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=35938752020-12-06T01:20:12Z2020-12-06T01:20:12ZThank you for your reply. I just realized that it was moved to a new section.*from bar mode calculation I have m = 4.96 so I expect multiple bars with the discharge and dimensions I provide.(Is the discharge the same across the upstream boundary? Or is there a variation in the lateral direction? )<br />*There is variation in discharge value along the transverse section with amplitude(+ or -) 1% in other words i have 30 cells on the transverse section and i have a total discharge with 1331 m3/s, so i divide (1331/30 = 44.37 m3/s per cell then I use code to make a perturbation along the transverse cross-section with amplitude (+ and -1%) so the values of discharge per cell are randomly between ((44.37+0.01*44.37) and (44.37-0.01*44.37)).<br />*my channel is 655m width*12000 m length (cell size (22.83 m*40m )) and the bed slope 3.5 cm/Km<br />*Horizontal eddy visc = 1 , Hz eddy diffusivity = 10* I use only sand with (d50 =0.378 mm) and I did not impose sediment transport concentration, I use equilibrium sand concentration profile at the inflow boundaries*Initial sediment layer thickness at bed =10 m*bedslope effect (Koch and flokstra)alfabs =1, Ash=9, Bsh=0.5, Csh=0.3, Dsh=1*Secondary flow Espir =0.5(That reinforces the feeling that you want to have forced bars. In that case, check whether you may have them imposing a variable discharge with time.)<br />*I did not get this point completely, do you mean if I impose variable discharge with time, I would not reach equilibrium bar mode (bed formation)? so if I want to run like a real case with different daily discharges along with the whole time series, you mean I will not reach equilibrium? <br />*In my simulation, I imposed variation in discharge with amplitude (+or - 1%) of Qtotalalong the whole time series.<br />Thank you for your help!<br />Regards, H A2020-12-06T01:20:12ZBars in riversH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=35812722020-12-02T04:45:01Z2020-11-30T20:26:46ZHi, I have a question. I built up my model as a straight channel 2DH simulation. Then I put perturbation in the upstream boundary (discharge per cell) to trigger instability and bar formation. The perturbation was with intensity 1% for each cell and I added noise to discharge along with the time series as well (change in discharge amplitude every 60 minutes (my time step is 0.5 minutes)) and my model begins to produce bars but after around 30 years of the simulation the bars tends to disappear and I did not reach the equilibrium state with my model. what could be my mistake? <br />2- changes in bed began to appear after more than 5 years of simulation I think it is a bit slow, what could be the reason ??<br />3- When I used the equation of E-H there are morphological changes but when I tried Van Rijn 1984 with the recommended value (Acal = 1, AKS = 1, Ws(settling velocity calculated) =0.04) the bed morphology is the same, what could be the reason?H A2020-11-30T20:26:46ZSecondary flowH Ahttps://oss.deltares.nl/c/message_boards/find_message?p_l_id=3228466&messageId=35359542021-01-05T08:10:04Z2020-11-11T08:02:59ZI have a question about simulating spiral flow.My case is 2DH simulation of a straight channel and I want to activate the spiral flow in my model. I activated the secondary flow in the process window but when I generate *.mor file to change Espir (calibration factor of spiral flow) it is not there, however, I checked another model used and I opened the *.mor file and the Espir is addressed there. Is it a problem of the different versions or should I do something to my model?<br />here is a link to the photo of different *.mor files : <a href="https://drive.google.com/file/d/1LC4bYZcRzdrlpGpILnmlFn2tob9hKfJt/view?usp=sharing">https://drive.google.com/file/d/1LC4bYZcRzdrlpGpILnmlFn2tob9hKfJt/view?usp=sharing</a><br />what about the initial value of secondary flow in the initial condition, I put it (v=0m/s), is it ok?What is the appropriate value for Espir?H A2020-11-11T08:02:59Z