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Transient heat transfer in fluid issue
Posted 2018年4月30日 GMT-4 09:27 Fluid & Heat, Computational Fluid Dynamics (CFD), Heat Transfer Version 5.3 2 Replies
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Hi everyone,
I'm now modeling a simple case that a 2d laminar flow with temperature T1 goes through a pipe (T2, and T1 > T2) with a constant velocity. I'm studying the transient state. What seems not physical is that in the temperature results profile, if initial T1 is higher enough > 500K, a little bump will appear in the first couples (0-40s) of seconds, and smooths out when it approches to the steady state (50-100s). I had tried two initial boundery conditions for fluid (temperature or inflow), both showed the weired behavior. (as shown in figure below) I'm curious about where these "bumps" come from? Cause I didn't add any external heat source into the system. The mph file is attached as well. Does anyone have an idea?
https://image.ibb.co/my9pjH/Comsol_temp_0_100s_line.png
THANK YOU IN ADVANCE!!!
Xiaoyu
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