Thank you for your reply. In my case, I used Hydraulic Diameter of Rectangular Tubes or Ducts.
However, the size of the rectangular tubes is different (decreasing). We can see it in the picture above.
In the first, size is 1.5 cm x 2.6 cm then it will decrease until 0.3 cm x 2.6 cm.
Do you have...
Hi, I just confuse how to know this hydraulic diameter, would you mind to help me?
hydraulic diameter is for reynold calculation then heat transfer coefficient.
Thank you