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Temperature input settings at Pressure Boundary Condition

Question asked by Igor Isayev on Oct 14, 2010
Latest reply on Oct 18, 2010 by Igor Isayev

I’ve ran CFD transient study for an application with (2) volumetric heat sources and a cooling fin between them. Cooling fin has Inlet and Outlet ports as well as a flow field for the coolant to pass through it and to pick up the heat from those (2) hot bodies. Inlet Volumetric Flow has initial temp. (20C) and has a complex flow cycle (5 min. pump off, 30 sec. on). Heat source rate is also time dependent (it does not matter for the case).
When the maximum fluid temperature at the Outlet port was plotted for the first 1000 sec., I’ve noticed that the maximum outlet temperature starts rising from initial 20C up to 30C and has no change after 30C that did not have much sense to me (see attached JPEG). The minimum and average temperature values showed all values between 20C & 30C though.  Analyzing the nature of the temperature 30C as the potential upper temperature limit, I realized that this temperature was initially setup at the Outlet where I applied Static pressure condition.
Currently, the pressure condition requires the temperature input in Flow Simulation Dialogue box.

I wonder whether the pre-set temperature at Pressure BC has any effect to the actual temperature of the flow. If yes, how to eliminate this effect and get the actual temperature data of the outlet flow? 

Thank you.

 

2010-10-14_170703.jpg.
 

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