{"id":163299,"date":"2021-10-22T10:47:56","date_gmt":"2021-10-22T10:47:56","guid":{"rendered":"\/forum\/forums\/topic\/transient-heat-simulation-using-fdtd-pabs-as-import-heat-source\/"},"modified":"2021-11-26T21:50:36","modified_gmt":"2021-11-26T21:50:36","slug":"transient-heat-simulation-using-fdtd-pabs-as-import-heat-source","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/transient-heat-simulation-using-fdtd-pabs-as-import-heat-source\/","title":{"rendered":"Transient Heat Simulation Using FDTD Pabs as Import Heat Source"},"content":{"rendered":"
\n
\n

Hi, <\/p>\n

I am trying to use Lumerical FDTD alongside Lumerical HEAT to simulate the photothermal heating and cooling of a nanocylinder. Following from this example in plasmonic nanostructures (Photothermal heating in plasmonic nanostructures – Lumerical Support<\/a>), I have first simulated a single nanocylinder on a substrate in FDTD with a TFSF laser source to determine the absorbed power(Pabs) (using the Pabs adv analysis group) within the cylinder. As in the example, I have been able to plot the spatial distribution of Pabs within the cylinder as a result of the laser. <\/p>\n

My problem now is within HEAT, as I am struggling to adapt the example simulation to allow for transient heat simulations. Currently, I am able to use the FDTD Pabs data as the imported heat source, and I can simulate the temperature distribution as a result of this imported heat source, but only in a steady state situation. When I try to use the transient heat solver I am told there is an error; from my understanding, the only way to use the transient heat solver is to set a temperature of power boundary condition, choose 'bc mode: transient', and set a changing temp or power in timesteps (as detailed here: Transient heat flow in a graphene-coated glass – Lumerical Support<\/a>). <\/p>\n

In my situation, the aim is to import the Pabs data within the cylinder as a pulsed heat source, and to simulate the heating\/cooling that occurs in time after the heat source, i.e., to import the Pabs data as a single source of energy rather than a rate\/power. Is it possible to import the heat source as an energy and then plot the time-dependent heating and cooling as a result of this pulsed energy gain? I can see from the steady-state simulation the rough temperature that my nanocylinder should reach, so I can possibly make a crude estimate of the initial temperature and see how this changes in time through transfer to the substrate etc, but I am unsure how to go about this as I do not want to set my own transient temperature\/power boundary condition.<\/p>\n

Any help or advice is greatly appreciated! Thanks \ud83d\ude42<\/p>\n","protected":false},"template":"","class_list":["post-163299","topic","type-topic","status-closed","hentry","topic-tag-fdtd","topic-tag-Heatsolver-1","topic-tag-heat-transfer","topic-tag-photothermalheatgeneration-1","topic-tag-transient-thermal"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t