Laminar Flow Nozzle
Front and rear views
nozzle was a quick build after a video of a running Laminar flow nozzle
was posted on the Make Magazine blog. As I have been experimenting with
ideas for building fountains for a project in summer 2011 it inspired
me to knock together a basic prototype.
I found the information at the forum: http://laminar.forumotion.com/
to be invaluble. The project was up and running in two evenings of
tinkering in the garage, and some time reading up the background over a
couple of lunchtimes.
It seems common for nozzles to be at least 4" diameter, and more
usually 6" to 8", however for my needs, the nozzle doesn't need to be
any where as big as I wanted a small jet, so I scaled down the ideas.
Apart from the straws, all the other parts were in stock, which has
driven the design.The main body is manufactured from a piece of
aluminium pipe, 35mm bore about 150mm long. The end plates are
aluminium sheet approx 1.5mm thick, held together with M6 studding and
with gaskets cut from Nitrile Rubber sheeting.
Following the flow of water;
Water enters through a 6mm push-fit fitting, secured to the base plate
with an 1/8" BSP nut. Water then passes through two layers of nylon cut
from a scouring pad, before hitting a thin piece of aluminium sheet to
divert the flow sideways, where it then meets two more layers of
scouring pad. On top of this is a piece of perforated aluminium sheet,
all spaced by a strip of nylon shim. This stack up is approx 15mm. Next
the water flows through the usual pack of drinking straws, topped off
with a piece of brass mesh. Finally there is another piece of nylon
shim approx 35mm before the nozzle cap is reached. The nozzle is simply
a 4mm hole, countersunk at 100 degrees, and then polished.
The nozzle was connected to the tap with a length of hose and run up, I
can get about 18" of parabola with a smooth flow. Checking the flow
with a weir gauge gave a flow of approx 1 lpm before the flow breaks up.
Laminar Nozzle Component Parts
Left to right;
6mm pushfit fitting
Aluminium end plate and nitrile rubber gasket
Nut to secure fitting
More scouring pad
Nylon shim used as spacer
Perforated aluminium sheet
Brass mesh screen
More nylon shim as spacer
At the rear is the aluminium tube and the lengths of studding used to secure it all together.
There is plenty of potential for improvements, but I'm very happy with it as a first pass.Clear Nozzle
This nozzle was
built as a slightly larger nozzle, and built clear for interest. The
assembly is very similar to the nozzle above.