What can cause the laminar flow to break?

It is necessary to develop a laminar flow installation 2-2.5 meters high and 3 meters long. Looking through various materials from the Internet, I put together a laminar flow installation on my own, and achieved the desired effect. But, there is a problem: the jet starts to disperse from the top point of the arc. What can influence this?

Maxim2606 wrote:It is necessary to develop a laminar flow installation 2-2.5 meters high and 3 meters long. Looking through various materials from the Internet, I put together a laminar flow installation on my own, and achieved the desired effect. But, there is a problem: the jet starts to disperse from the top point of the arc. What can influence this?

Dear Sir
I want to know low pass filter in laminar water jet, how to built low pass filter in laminar nozzle?
area at bottom, where water inlet or area at top, where nozzle, where low pass filter built?
i tried laminar jet, but after some distance water is spread, not good laminar .
result is I need to built low pass filter to get proper laminar jet.
Please guide me about laminar nozzle along with sketch and dimensions.
Your reply is appreciated