Re: [Yade-users] [Question #269831]: HydroForceEngine not defined?
Question #269831 on Yade changed: https://answers.launchpad.net/yade/+question/269831 Status: Open => Answered Raphaël Maurin proposed the following answer: Hi >It obviously is not included in the current release of Yade, is it strange? I am actually not using at all the stable versions so I don't know if it is strange, but I commited that engine months ago. >well, i'm actually want to simulate the buoyancy of the sphere. however, it seems that all the spheres drop to the bottom anyway due to gravity It should be possible to simulate the buoyancy with hydroforce engine by putting the vxFluid to a vector full of zeros, and the mesh properties in order to fill the whole space. If you want the particle to have buoyancy applied only if it is under the water surface, just precise the fluid mesh from the ground to the water free surface wall normal position: h =nCell*dz. This will apply the buoyancy only if the center of the particle is inside the water. However it will not take into be modified if a part of the particle is outside the water. You can modify that in the C++ code if necessary. Depending on the number of particles that you are simulating, it might be easier for you to write a simple function in python using O.forces.addF(O.bodies[0].id,fb) which will apply the force fb (that you can evaluate easily) to the particle O.bodies[0] for example. >. By introducing the hydroforce engine, should the sphere be kind of floating >on the water surface if the density is >lower than the water density? If you have a buoyancy force, this should be the case > say if the sphere is only partly submerged, then the buoyancy should be only calculated from the submerged volume, isn't it? This should be the case but is not evaluated like that inside the HydroForceEngine. Hope it helps Raphael -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #265943]: How to get the induced Stress/strain in DSR test?
Question #265943 on Yade changed: https://answers.launchpad.net/yade/+question/265943 Status: Answered => Solved behzad confirmed that the question is solved: Thanks Jan Stránský, that solved my question. -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #269831]: HydroForceEngine not defined?
Question #269831 on Yade changed: https://answers.launchpad.net/yade/+question/269831 huisky gave more information on the question: and what's more, i'm not sure how does the HydroForceEngine know the elevation of freesurface? say if the sphere is only partly submerged, then the buoyancy should be only calculated from the submerged volume, isn't it? -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #269831]: HydroForceEngine not defined?
Question #269831 on Yade changed:
https://answers.launchpad.net/yade/+question/269831
Status: Answered => Open
huisky is still having a problem:
Hei,
by issuing help(HydroForceEngine) in Yade, I got following message:
Welcome to Yade 1.07.0
TCP python prompt on localhost:9000, auth cookie `dcessy'
XMLRPC info provider on http://localhost:21000
/usr/lib/python2.7/dist-packages/IPython/frontend.py:30: UserWarning: The
top-level `frontend` package has been deprecated. All its subpackages have been
moved to the top `IPython` level.
warn("The top-level `frontend` package has been deprecated. "
[[ ^L clears screen, ^U kills line. F12 controller, F11 3d view (use h-key for
showing help), F10 both, F9 generator, F8 plot. ]]
Yade [1]: help(HydroForceEngine)
---
NameError Traceback (most recent call last)
/usr/bin/yade in ()
> 1 help(HydroForceEngine)
NameError: name 'HydroForceEngine' is not defined
It obviously is not included in the current release of Yade, is it strange?
I've tried to use Yadedaily and it works!
well, i'm actually want to simulate the buoyancy of the sphere. however,
it seems that all the spheres drop to the bottom anyway due to gravity.
By introducing the hydroforce engine, should the sphere be kind of
floating on the water surface if the density is lower than the water
density?
maybe there are something i'm still missing?
O.engines=[
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Facet_Aabb(),Bo1_Wall_Aabb()],label='collider'),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom(),Ig2_Facet_Sphere_ScGeom(),Ig2_Wall_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys()],
[Law2_ScGeom_FrictPhys_CundallStrack()],
),
NewtonIntegrator(damping=.1,exactAsphericalRot=True,gravity=(1e-2,1e-2,-10.)),
TranslationEngine(translationAxis=[1,0,0],velocity=5.0,ids=[id.id for id in
strut]),
HydroForceEngine(densFluid=rau_wat),
]
Regards
Liu
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Re: [Yade-users] [Question #269831]: HydroForceEngine not defined?
Question #269831 on Yade changed: https://answers.launchpad.net/yade/+question/269831 Status: Open => Answered Raphaël Maurin proposed the following answer: Hi, I think HydroforceEngine should be defined for your Yade version. If you want to be sure it is defined, try to type help(HydroForceEngine) in Yade. If it prints something it is defined. Otherwise use the latest yadedaily and it will be ok. However, I don't know what you want to simulate, but with your formulation it will not work. You need to precise all the different arguments of the engine (see the documentation https://yade- dem.org/doc/yade.wrapper.html?highlight=hydroforceengine#yade.wrapper.HydroForceEngine ). I designed this function to couple Yade with a 1D fluid resolution (v_x^f(z)) so that it mights look a bit particular at some points. It therefore requires to precise the fluid profile (vxFluid) and the position (zref) of the regular fluid mesh described by deltaZ and nCell. There is also a Discrete Random Walk fluctuation model included to account for the fluid velocity fluctuations, which is based on the Reynolds stress tensor (which comes from the fluid resolution). You can get rid of the fluctuation model by writing HydroForceEngine(vFluctX = numpy.zeros(len(O.bodies)), vFluctZ = numpy.zeros(len(O.bodies))) when declaring the engine. Don't hesitate if you have more questions. Raphaël -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
