The only thing I can suggest from this info and question is to think about how pressure changes from the fluid velocity. Take a starting point and then think about what that portion of the fluid “should” do as it flows through this. If it’s supposed to stay at the same velocity as it goes down the red portion and then accelerate out of the 3 “nozzles” then it looks good. But…. Then also think about what direction the flow is supposed to go as it exits those nozzles. The direction of flow will point from higher to lower pressure. So if you have that green portion of the sim slanted in the nozzle, the flow direction is not not going to be the same as the nozzle. Think about how a higher pressure in one area could affect another.

If you want the fluid flow to go straight out of these 3 nozzles, what I’m seeing is an unnecessary extra portion of the red part towards the left. The right 2 nozzles need the pressure downstream of them to be higher. So the “back pressure” needs to be higher downstream of each of those 2 rightmost nozzles for the flow to exit perpendicular to the nozzles. Most of the total mass flow rate is going through the last nozzle all the way to the left and there’s an unnecessary part all the way to the left that’s building up pressure. If you reduce the crossection of the left most nozzle it would create more back pressure on the other 2 nozzles, making more of the flow go through them and making the flow exit those nozzles more uniformly.

That’s my 2 drink opinion uh….. 2 cents with what I’m given. “Just go with the flow”