[Sripadaraja]

I request help in understanding one of the flow behavior that I notice. I am attaching a document for your reference.

I am working on droplet microfluidics. Below are my simulation conditions.

Velocity of water (Red) = 0.002m/s (fixed throughout simulation)
Velocity of Oil (Blue) = 0.004m/s (fixed throughout simulation)

Situation 1: When I increase the width of the side channel (ONLY), liquid pressure also increases (at points marked).

Situation 2: When I increase the width of the main channel (ONLY), liquid pressure decreases (at points).

I am unable to relate the two phenomena using general flow behavior (Bernoulli's equation). I discussed this with some of my lab mates and I am unable to get a convincing answer. Kindly share your thoughts on this and educate me on my understanding.

Let me know if there is any information missing, that I can provide.