Here is my first animation of a cytonozzle flowcell. I did this in Blender 2.8a. It is a simple rendition, but I think it came out alright for a first try. You may use this animation in your talks etc. under the license found here: CC BY-NC-SA 4.0. Keep in mind that the particles normally would normally enter the main stream right before the final neck-down region. However I decided that would would a bit overkill but keep in mind, if we introduce the sample too early then turbulence will eventually take over.
Laminar flow

In this case the sample to sheath pressure is optimal keeping the particles in the center of the stream due to good hydrodynamic focusing.

Turbulent flow

In this case let's imagine that one increases the sample to sheath pressure so much that the particles now have too much room to move around in. In this case, the particles will be near, but focused to the center. In this case one will have much more noise and a poorer resolution.