The directions which water pumps are pointed within an aquarium will have a large effect on flow speeds.
The most obvious ones are their width and flow speed.
Even so, flow speeds are typically only a few millimeters per second.
The above equations use a linear relationship between flow speed squared and pressure.
It is also used to obtain a standard profile in a wind tunnel (temperature, flow speed).
These all turned out to be correct for low flow speeds.
This is more likely to be true when the flow speeds are significantly lower than the speed of sound.
At the downstream front the vehicles accelerate to the free flow speed.
Conservation of mass says that the flow speed must increase as the stream tube area decreases.
As mentioned above is determined by the application of fan i.e. flow speed.