> On 5. Nov 2018, at 02:55, Ranjeet kumar <ranjeet...@gmail.com> wrote: > > Dear All, > Would you please explain the followings: > > 1. For Neumann Boundary and Source, unit are [kg/(m^2.s)] and [kg/(m^3.s)]. > In the input file, I want to give rate [kg/s] for both Neumann bc and source. > Do I need to divide the rate by scv's area/scv's volume in the neumann() and > source() method respectively? Similarly, for method > neumannAtPos()/sourceAtPos(), rate/(domain's area/volume ). >
Hi Ranjeet, For both functions neumann/neumannAtPos you need to divide the total mass flux (in kg/s) by the total injection/extraction area. You need to make sure that your mesh resolves the injection area exactly to get the exact total boundary flux. If this is not the case, the value will be approximated better and better with grid refinement. For both functions source/sourceAtPos you need to divide by the total volume of injection. Again, you need to resolve you volume of injection exactly by the grid. If you divide by the area/volume of the sub control volume instead, it would mean that you inject at your given rate for _every_ sub control volume, i.e. if you are refining your grid you would inject more and more. There is also point sources (see e.g. the 1p point sources test for how to use the interface), in case you want to inject at a singular point. There you specify the value in kg/s and give a position. Dumux is going to find the right sub control volume for you. > 2. In 2p cornerpoint, FLuidSystem::phase1dx is used as indices for source() > whereas in , 1p implicit, contiW/NEqIdx used. Are both the indices same? > Could you please explain how indices works? The source function returns an array with the size number of equations. You have a mass balance equation for every component. For the 2p model, phases and components are the same, since the components are considered immiscible. The index is determined by the fluid system. The mass balance for the first component will have index 0, the mass balance for the second component will have index 1. To make that clear, you can use FluidSystem::comp0Idx/FluidSystem::comp1Idx or (in the 2p immiscible case only) FluidSystem::phase0Idx/FluidSystem:: phase1Idx. Usually, you would rename these indices in the problem header for better readability. If you’re dealing with water and nitrogen for example, you might define something like enum { H2OEqIdx = FluidSystem:: comp0Idx, N2EqIdx = FluidSystem:: comp1Idx }; or whatever you find readable, _and_ set water as your first phase and nitrogen as your second phase in the fluid system. If you change the order in the fluid system, the order of the equations will change as well. Best wishes Timo > > > Thank you, > > Regards, > Ranjeet > _______________________________________________ > Dumux mailing list > Dumux@listserv.uni-stuttgart.de > https://listserv.uni-stuttgart.de/mailman/listinfo/dumux _______________________________________________ Dumux mailing list Dumux@listserv.uni-stuttgart.de https://listserv.uni-stuttgart.de/mailman/listinfo/dumux