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Using Cylindrical Coordinates to calculate forces from pressure

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Hi All,

I'm in the process of trying to find the pressures exerted by a flow onto a turbine using the pressure. I've been using cartesian coordinates, which I believe my gives me the correct force in the z axis (the direction of flow), but however does not given an useful representation in the x and y axis.

I have decided to use the cylindrical coordinate system, and have added it under my definitions. However, I cannot figure out how to use the system with my results, as they still seem to be in cartesian form. I've been looking through the settings, and cant seem to find anywhere to change the system from cartesian to cylindrical in the physics module, or in the solver option?

I've changed the boundary system (sys1) under definitions to use the cylindrical system (sys2), and have run the study again, is this the correct thing to do?

I've been using a surface integration with the expression below to find the overall force on the turbine, but I not sure if its possible just to swap out the axis labels with the new cylindrical ones?

spf.nymeshp + spf.rhospf.u_tau*spf.u_tangy/spf.uPlus

Sorry for the amount of questions! It's my first time trying to change the coordinate system


0 Replies Last Post 19 mar 2018, 09:57 GMT-4
COMSOL Moderator

Hello Tom Mapp

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