Missing water flow in sub-inlets

Dsreedeth · February 17, 2020, 14:42

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?

ghorrocks · February 17, 2020, 17:11

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.

Dsreedeth · February 18, 2020, 05:35

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?

ghorrocks · February 18, 2020, 06:11

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.

February 17, 2020, 17:11		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,852 Rep Power: 144	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, 06:11		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,852 Rep Power: 144	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.

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February 18, 2020, 05:35		#3
Dsreedeth 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?