# Missing water flow in sub-inlets

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February 17, 2020, 13:42
Missing water flow in sub-inlets
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Dyuthi
Join Date: Feb 2020
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Hi all! I am trying to simulate this system where cold water enters a main inlet manifold which feeds into multiple smaller rectangular channels which get collected at the bottom manifold and exits the system (essentially a simplified box-frame solar thermal collector-pic attached). While checking the results I figured that the water seems to enter only a few channels (pic of velocity streamline included). Is there anything I can do to ensure the water enters all the channels?
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 February 17, 2020, 16:11 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,327 Rep Power: 138 Streamlines are not a reliable way to work out how much fluid is going though each passage. I will let you work out why You should generate a cross section plane through the passages and look at the normal velocities. Even better, generate a plane for each passage and use the massflow() function to give the exact flow in each passage. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

 February 18, 2020, 04:35 #3 New Member   Dyuthi Join Date: Feb 2020 Posts: 2 Rep Power: 0 Thanks for the suggestion. I generated the cross section plane and the velocity is zero in the channels where water does not enter. So is there any way I can ensure water enters these chanels?

 February 18, 2020, 05:11 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,327 Rep Power: 138 Have a look at the pressure across your device. Here's a hint: If a channel has no pressure gradient along it then it will have no flow. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

 Tags fluid dynamics, heat exchanger