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The red arrow marked box shown below is to be tested at an ambient temp of 100 C. How to give constant temp to the ambient air ? (I have considered the ambient air as a solid surrounding the box)
Hello, Can you give more details on the complete system? What are the goal? It seems you're using AcuSolve, so doing CFD simulation. Is the blue body a solid? If you want to apply 100C to from the surrounding to the body. You can apply a wall BC with thermal set as temperature to 100C.
Kind regards,
Marc
I would agree with the comment from Marc - more detail about the complete system would be helpful. If you want a constant temperature of 100 C (373.15 K) on the outer boundaries, that would be through the boundary condition on the wall (no need for the additional meshed volume). You could also estimate instead some convective heat transfer to the ambient/room by using the default wall BC of heat flux = 0, but adding a convective heat transfer coefficient (say 10-12 W/m2-K) with the farfield temperature of 100 C (373.15 K).
I am performing a CFD simulation to analyze the temp distribution within a box (shown below in blue colour) when it is subjected to ambient air temp 100C. I am using simlab acusolve. Yes, the blue body is solid.
Can i use this boundary condition option to apply as to set the ambient temp as 100C?
Hello sandeep,
If you're only interested in the solid and applying a 100C BC on the surface between the solid and fluid. I'd recommend using a Heat Transfer Solution with OptiStruct and not a CFD analysis for a structural case. Is this the only BC? In that case you can apply directly a temperature load to the surfaces of interest:
Marc Steiger
Hi Marc,
The goal of the simulation is to obtain the temp distribution of a PCB board inside a box when the box is subjected to ambient temp of 100C. I need to model the air volume inside the box as well. Outside the box, maybe I could use a wall condition as you said. But CFD simulation is required to get the temp behaviour of the air inside. The model is shown below.
The other BCs are
1) Heat load of the PCB components
2) Coolant channel flow rates
I hope both the approaches: Using a wall in acusolve OR keeping constant temp in optistruct - both will yield the same effect?
Best regards,
Sandeep
We appreciate the extra detail. If you need the fluid volumes - internal air, coolant channels - you'll probably need the CFD model. If you want a constant temperature of 100 C (373.15 K) on the outer boundaries, that would be through the boundary condition on the wall, with no need for the additional meshed volume on the outside. You could also estimate instead some convective heat transfer to the ambient/room by using the default wall BC of heat flux = 0, but adding a convective heat transfer coefficient (say 10-12 W/m2-K) with the farfield temperature of 100 C (373.15 K).
Hi Sandeep,
This is also a great case to use the Electronics Thermal Solution in SimLab. I recommend watching this tutorial in the SimLab learning center "SL4023 Liquid Cooling" (this includes air and the other fluid coolant). You'll also find it under Electronics Thermal-Version 2025-System Level Analysis
https://web.altair.com/altair-for-simlab-learning-center-trls
