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Heating A Silicon Waveguide Using Metal Heater
Posted Apr 14, 2023, 12:39 p.m. EDT Heat Transfer 6 Replies
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Hello. I am new to COMSOL and am trying to heat a waveguide with a metal heater. The model is 2D and in steady state. I am actually trying to reporduce the results of a paper which applies the following boundary conditions "The width and height of the heater are set to 5 µm and 0.2 µm, respectively. The silicon waveguide is situated 1 µm below the heater and the space between them is filled with silica. The boundaries of the simulation area are located 10 µm from each edge of the heater and are set to thermal insulation boundary condition. The initial values are set to zero and the heat flow is modeled by setting the temperature of heater as a function of voltage (equation attached below - I am using V=1 V due to steady state study)." The problem I am facing is that the heat does not flow outside the heater to the waveguide.
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Hello Ayesha,
You attached the wrong mph file. In any case, my first thought would be that you should contact the author(s) of the paper since they may be able to provide you with the actual file they based the paper on.
Best,
Jeff
-------------------Jeff Hiller
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I am reattaching the file for your ease. Can you please have a look?
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It's still not the right file.
Jeff
-------------------Jeff Hiller
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Sorry for the inconvenience. Is this okay now?
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Hello Ayesha,
The reason "the heat does not flow outside the heater to the waveguide." in your model is simple. You have effectively split your model into two separate problems: one in the heater, one in the rest of the geometry. Consider the region outside the heater. There are no sources in that region, and you are imposing the temperature at the boundary with heater as 293.15K and insulation conditions on the other outer boundaries. The solution of the conduction equation in that region is therefore the trivial one, a uniform 293.15K, and that's what COMSOL returns.
Having not read the paper, I am afraid I cannot say for sure how its authors modeled the physical phenomenon exactly, and I would therefore reiterate my suggestion that you contact them, but they can't have set the temperature at the boundaries of the heater (If that temperature was known a priori one would not include the heater in the simulation, after all). Simply removing that temperature boundary condition would not solve your problem either because there is no steady state solution if there's a heat source and nowhere for the heat to escape the system (the outer boundaries being currently insulated).
Best,
Jeff
-------------------Jeff Hiller
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Hello Jeff. Thank you for your detailed response. I have contacted the authors but it is quite rare for the authors to reply, I think. Also yes, I tried removing the temperature boundary condition and applied heat flux to the top boundary. It does not work that way and gives me an error (attached below). In case, you want to have a look at the paper, it is here: https://ieeexplore.ieee.org/document/8169026
Thank you,
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