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writing a equation in Comsol giving error
Posted 2016年7月14日 GMT-4 05:40 Low-Frequency Electromagnetics Version 4.4, Version 5.0 3 Replies
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Hi all,
It might be a basic question for most of the people but i am very new to Comsol Multiphysics please help me out.I Am trying to write Poisson 3D/2D equation in variables section but it was giving me syntax error(red colour) ,i tried differently to enter the equation like copy/paste my equations are as follows :
1)3D-Poisson equation - Ɛr(x,y,z)Ɛ0*∇^2ϕ(x,y,z)=-ρ(x,y,z),
2)2D-Poisson equation Ɛr(x,y)Ɛ0*∇^2ϕ(x,y)=-ρ(x,y).
looking forward for response.
Thanks and Best Regards,
Manoj
It might be a basic question for most of the people but i am very new to Comsol Multiphysics please help me out.I Am trying to write Poisson 3D/2D equation in variables section but it was giving me syntax error(red colour) ,i tried differently to enter the equation like copy/paste my equations are as follows :
1)3D-Poisson equation - Ɛr(x,y,z)Ɛ0*∇^2ϕ(x,y,z)=-ρ(x,y,z),
2)2D-Poisson equation Ɛr(x,y)Ɛ0*∇^2ϕ(x,y)=-ρ(x,y).
looking forward for response.
Thanks and Best Regards,
Manoj
3 Replies Last Post 2016年7月15日 GMT-4 11:03
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Posted:
8 years ago
Hello Manoj,
The electrostatics equation is already implemented in COMSOL (in the Model Wizard, select AC/DC and Electrostatics), so we would not recommend you re-invent the wheel here, unless you have a good reason to do so that you did not mention.
With that said, if you must implement an equation from scratch, the Reference Manual, version 5.2a, Chapter 16 documents the equation-based modeling interfaces. All manuals are accessed through the File > Help > Documentation menu.
Best,
Jeff
The electrostatics equation is already implemented in COMSOL (in the Model Wizard, select AC/DC and Electrostatics), so we would not recommend you re-invent the wheel here, unless you have a good reason to do so that you did not mention.
With that said, if you must implement an equation from scratch, the Reference Manual, version 5.2a, Chapter 16 documents the equation-based modeling interfaces. All manuals are accessed through the File > Help > Documentation menu.
Best,
Jeff
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Posted:
8 years ago
Hi Jeff,
Thanks for your reply as i told you i am new to Comsol i don't know that these equations are in built .In that case i don't need to declare parameters also am i right.I will upload my model here with the complete description what we are aiming to do and how we are approaching.
Thanks in advance
manoj
Thanks for your reply as i told you i am new to Comsol i don't know that these equations are in built .In that case i don't need to declare parameters also am i right.I will upload my model here with the complete description what we are aiming to do and how we are approaching.
Thanks in advance
manoj
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Posted:
8 years ago
Hi Manoj,
I'm sure you'll love the interface for electrostatics. It's very straightforward to use.
You'll see that the interface will ask for the relative permittivity, of course, and you'll need to enter your desired expression for the charge distribution rho. The rest is done for you.
Best,
Jeff
I'm sure you'll love the interface for electrostatics. It's very straightforward to use.
You'll see that the interface will ask for the relative permittivity, of course, and you'll need to enter your desired expression for the charge distribution rho. The rest is done for you.
Best,
Jeff