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Creating (and using) an involute coordinate system

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I've defined an involute coordinate system using an interpolation function. For an unstructured grid of x and z coordinates, I have defined two new coordinates t_coord and h_coord which have vectors everywhere parallel to a circular involute and everywhere perpindicular to a circular involute, respectively.

I can't figure out to make COMSOL recognize them as a new reference frame however. For instance, in the general projection model coupling feature I would like to be able to use t_coord and h_coord as my directions of value storage and integration. Also, in output plots I would like to be able to enter them as expressions to use along my x and y plot axes.

I've tried making variables out of the interpolation functions (t_coord_var = t_coord(x,z) ...) but that still does not seem to work. I've also tried making a new coordinate system with the option under "definitions" using these new coordinates, but that doesn't seem to work either. It's also possible that one of these methods have worked but I am calling the resultant variables by the wrong thing when attempting to access them later. But, for instance, if the variable t_coord_var is valid then I would think I should be able to access it simply by typing "t_coord_var" into the coordinate expression field.

Any help is appreciated.

Thanks

Adam

1 Reply Last Post 2013年5月1日 GMT-4 14:44
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2013年5月1日 GMT-4 14:44
Hi

COMSOL adds into it 's coordiante drop down list only those you define fully in the "model - definitions - coordinate systems" nodes. So if you make a special one, that is fully possible, you ust then also write out the coordinate transform directly from the default cartesian coordiante system, and this for each equation entry in thephyics and BC nodes

--
Good luck
Ivar
Hi COMSOL adds into it 's coordiante drop down list only those you define fully in the "model - definitions - coordinate systems" nodes. So if you make a special one, that is fully possible, you ust then also write out the coordinate transform directly from the default cartesian coordiante system, and this for each equation entry in thephyics and BC nodes -- Good luck Ivar

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