I have a pipe with ID=75 mm interrupted with an array of N=121 tubes (as shown in the drawing), forcing the air to flow inside the tubes (ID of each tube is 2mm) spaced apart by 5mm. How do I estimate the pressure drop of the outcoming air? If there is a white paper on this, I would appreciate a reference! My application would benefit from maximizing the N of tubes and reducing their IDs, but I need to know when to stop (i.e. when the air pressure drop becomes impractical).

I am aware of this thread which treats a different configuration (cross-flow around the tubes):

Method for computing the pressure drop across a bank of tubes

I have a pipe with ID=75 mm interrupted with an array of N=121 tubes (as shown in the drawing), forcing the air to flow inside the tubes (ID of each tube is 2mm) spaced apart by 5mm. Length of tubes is 50mm. How do I estimate the pressure drop for the outcoming air? If there is a white paper on this, I would appreciate a reference! My application would benefit from maximizing the N of tubes and reducing their IDs, but I need to know when to stop (i.e. when the air pressure drop becomes impractical).

I am aware of this thread which treats a different configuration (cross-flow around the tubes):

Method for computing the pressure drop across a bank of tubes