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Pointwise constraints for time derivatives are not supported
Posted 18 giu 2010, 12:03 GMT-4 2 Replies
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Hello,
I am having problems running a model in COMSOL 4.0 where I receive the error "Pointwise constraints for time derivatives are not supported". I am aware that this was discussed before and that boundary conditions should be applied to volumes, surfaces and edges at the least but where my confusion lies is that the boundary conditions used work in COMSOL 3.5a but not in COMSOL 4.0.
The model I am recreating is the peristaltic_pump.mph example available with COMSOL 3.5a. The fluid subdomain has displacement derivatives for input velocities, such as ut and wt, for example . Yet when these are used in the same fashion in COMSOL 4.0 the error message "Pointwise constraints for time derivatives are not supported" is returned.
I would like to know what changed from 3.5a to 4.0 that this model, defined in exactly the same manner, does not run consistently between both versions of the software.
Secondly, how do I get this model to solve?
Thank you for your time,
Tyler Bevan
I am having problems running a model in COMSOL 4.0 where I receive the error "Pointwise constraints for time derivatives are not supported". I am aware that this was discussed before and that boundary conditions should be applied to volumes, surfaces and edges at the least but where my confusion lies is that the boundary conditions used work in COMSOL 3.5a but not in COMSOL 4.0.
The model I am recreating is the peristaltic_pump.mph example available with COMSOL 3.5a. The fluid subdomain has displacement derivatives for input velocities, such as ut and wt, for example . Yet when these are used in the same fashion in COMSOL 4.0 the error message "Pointwise constraints for time derivatives are not supported" is returned.
I would like to know what changed from 3.5a to 4.0 that this model, defined in exactly the same manner, does not run consistently between both versions of the software.
Secondly, how do I get this model to solve?
Thank you for your time,
Tyler Bevan
2 Replies Last Post 18 mag 2011, 13:34 GMT-4