[pyxbird]

All dears,
Hi, I am trying to use sediment scour model to simulate the scour patter around a vertical cylinder under steady flow. And here are my quetions:
1. I know the meaning of critical and cohesive sediment fration, but I don't know how to define the values of them.
2. As we all know, we can define the seabed by--initial--fluid region--the sediment concentration--packed, here the value of packed=density of the sand(for example 2.65)*solid fraction of the sediment? And if it is true, so how to define the value of solid fraction of sediment(1? or 0.9?and so on).
3.In the fluid region, we also need to define the fraction of the fluid, if the solid fraction I input is 0.9, so the fraction of the fluid should be 0.1 of 1? When I choose 0.1, after the simulation is run the fluid above the seabed drops straightly down to the "seabed", but when I choose fraction of fluid=1,there is no problem, but I don't think it is reasonable(can there be such large amout of water in "seabed"?), so how to define the value of "fraction of fluid"?
4.After the simulation is done, how can I see the flow pattern in the tab "Analyze"? Is it like this: iso-surface--packed sediment concentration; color variable--strain rate? But I can't find more detailed information, for example the scour depth.
I will be grateful is someone can help me.

[JBurnham]

FLOW-3D v9.4.x includes packed sediment depth and rate of change in depth as output variables that can be used as the color variable when plotting packed fraction as the iso-surface. If you have an earlier version than that, you may have to experiment to find a good way to plot.

[JBurnham]

The solid fraction of the initial regions is the same as the 'maximum packing fraction' defined on the Physics dialog for the scour model. The different proportions of sediment are used to calculate the fractions of each species in that already-known solid fraction. Always set the fluid fraction = 1.0; even in the initial fluid regions: the sediment (both suspended and packed) is considered a two-phase mixture fluid, and that fluid must be 100% present (F = 1) in all submerged cells, otherwise there will be many pressure failures and collapse of the fluid.

[pyxbird]

Originally Posted by JBurnham

The solid fraction of the initial regions is the same as the 'maximum packing fraction' defined on the Physics dialog for the scour model. The different proportions of sediment are used to calculate the fractions of each species in that already-known solid fraction. Always set the fluid fraction = 1.0; even in the initial fluid regions: the sediment (both suspended and packed) is considered a two-phase mixture fluid, and that fluid must be 100% present (F = 1) in all submerged cells, otherwise there will be many pressure failures and collapse of the fluid.

Thank you JBurnham, you have helped me many times.

[mahdi1]

Hello pyxbird & JBurnham

I simulated a channel with movable bed by v10.
Could you please tell me that how can I take a plot of bed deformation and also How can I obtain maximum depth score in results file?

I would be thankful if you help me.

[mahdi1]

Originally Posted by pyxbird

All dears,
Hi, I am trying to use sediment scour model to simulate the scour patter around a vertical cylinder under steady flow. And here are my quetions:
1. I know the meaning of critical and cohesive sediment fration, but I don't know how to define the values of them.
2. As we all know, we can define the seabed by--initial--fluid region--the sediment concentration--packed, here the value of packed=density of the sand(for example 2.65)*solid fraction of the sediment? And if it is true, so how to define the value of solid fraction of sediment(1? or 0.9?and so on).
3.In the fluid region, we also need to define the fraction of the fluid, if the solid fraction I input is 0.9, so the fraction of the fluid should be 0.1 of 1? When I choose 0.1, after the simulation is run the fluid above the seabed drops straightly down to the "seabed", but when I choose fraction of fluid=1,there is no problem, but I don't think it is reasonable(can there be such large amout of water in "seabed"?), so how to define the value of "fraction of fluid"?
4.After the simulation is done, how can I see the flow pattern in the tab "Analyze"? Is it like this: iso-surface--packed sediment concentration; color variable--strain rate? But I can't find more detailed information, for example the scour depth.
I will be grateful is someone can help me.

Hello pyxbird
Could you please send me your prepin file.
Because I want to do same study.
I would be thankful, if you can help me.

[pyxbird]

Originally Posted by mahdi1

Hello pyxbird
Could you please send me your prepin file.
Because I want to do same study.
I would be thankful, if you can help me.

Sorry I didn't surf the Internet in the past days, I simulated that case last year and the prepin file is lost. And I will continue the work few months later.

[pyxbird]

Originally Posted by mahdi1

Hello pyxbird & JBurnham

I simulated a channel with movable bed by v10.
Could you please tell me that how can I take a plot of bed deformation and also How can I obtain maximum depth score in results file?

I would be thankful if you help me.

Firstly you should define a bed in Meshing&Geometry, and after the simulation is done, in Analyze Tab, 3D, you can find the bed height directly.