Model:Mrip

Contact

Name	Edith Gallagher
Type of contact	Model developer
Institute / Organization	Franklin and Marshall College
Postal address 1	PO Box 3003
Postal address 2
Town / City	Lancaster
Postal code	17604-3003
State	Pennsylvania
Country	USA"USA" is not in the list (Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, ...) of allowed values for the "Country" property.
Email address	edith.gallagher@fandm.edu
Phone	717-291-4055
Fax	717-358-4548

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Mrip

Metadata

Summary Also known as Model type Single Model part of larger framework Note on status model Date note status model Technical specs Supported platforms Windows Other platform Programming language Matlab Other program language Code optimized Single Processor Multiple processors implemented Nr of distributed processors Nr of shared processors Start year development 2003 Does model development still take place? Yes If above answer is no, provide end year model development 2010 Code development status When did you indicate the 'code development status'? Model availability As code Source code availability (Or provide future intension) Through CSDMS repository Source web address Source csdms web address Program license type GPL v2 Program license type other Memory requirements Typical run time ~1 hr (depending on duration of simulation) In/Output Describe input parameters Basic parameters for a sediment transport model (grain size, efficiency coefficients, coefficient of friction, wave friction factor, density, etc) most are in there using values from the literature, but easily modified. Flow. (Sinusoidal, steady or combined flows can be created, as well as natural flow data can be used.) A random "turbulent" flow is imposed - this needs a magnitude. Jump fraction - given distance sediment moves with flow Input format ASCII Other input format Describe output parameters Options (can be turned on or off): Print evolving bed to screen. A file with the bed with each time step, or at intermediate steps. A file with the spectra of bed at each time step, or at intermediate steps. A file with statistics (eg, rms roughness of bed) Output format ASCII Other output format Matlab files Pre-processing software needed? No Describe pre-processing software Post-processing software needed? No Describe post-processing software Visualization software needed? No If above answer is yes Other visualization software Process Describe processes represented by the model The bed is represented by a 2-D matrix. At this time the bed is 250 x 250. Each block (i,j) is taken to be a slab of sediment 10cm x 10cm x 1cm deep. A second matrix represents the flow. This is the same everywhere in the domain at each time point, except for a random spatial fluctuation representing turbulence. The user-defined flow picks up (or puts down) sediment according to a transport law. Three transport laws have been tested: Bailard (1981), Ribberink (1998) or simple rules. The simple rules are simply thresholds: (if flow greater than 70cm/sec pick up one block). Once sand block have been picked up, they are moved forward with the flow. Generally, I have used a fraction of the distance that the water would travel (jump_frac). So, with a flow of 100cm/sec, in one second that water goes 100 cm. The sand in this case would go 50 cm (half the distance). At the extremes, the model is sensitive to this parameter, but at intermediate values, it is not. Tested flows have consisted of combined sinusoidal flow+steady flow, purely osc, purely steady, and natural flow time series taken from current meter measurements. All flows have a random spatial fluctuation added at each time point. Once bedforms are generated, feedback rules are employed by altering the flow over the bedform. Once a bedform gets tall, the flow over the top accelerates, increasing transport at that location. In the steep lee of a bedform, a shadow zone forms where flow goes to ~zero, therefore transport goes to zero. These mechanisms destroy or build bedforms. Describe key physical parameters and equations "Key" parameters: the transport thresholds (if you use the simple rules) (it is cool, model results are similar with all the transport models that have been tested) the flow magnitudes and turbulence magnitude Jump_frac all the little parameters in the transport equations Most parameters act to speed or slow transport, which in turn speeds or slows the growth of bedforms. Describe length scale and resolution constraints With Matlab running on my desktop PC I get out of memory errors when I make the domain much bigger than it is at present (250x250). I am working to expand the model domain. I would also like to increase the resolution. (Isn't this what all modelers want to do?) Describe time scale and resolution constraints One second has been the time resolution. I haven't played with this. Describe any numerical limitations and issues Testing Describe available calibration data sets The model has been compared qualitatively with Clarke and Werner (2004), Gallagher et al 1998, 2003 and 2005 and various Hay papers. Upload calibration data sets if available: Describe available test data sets Upload test data sets if available: Describe ideal data for testing Other Do you have current or future plans for collaborating with other researchers? yes. Is there a manual available? No Upload manual if available: Model website if any Model forum / discussion board Comments Introduction History Papers Issues Help Input Files Output Files Download Source