Jet Sprays - Applied Friction Modifiers (KELTRACK®)

Goal:

- To precisely measure the diameter of a ~500 micron liquid jet to determine the jet velocity as a function of applied back pressure.

To begin, a circular nozzle needed to be fabricated. This was first done by conventional drilling; though, the results were unsatisfactory. EDM machining produced a much better product.

The back side of the nozzle as seen by a scanning electron microscope (SEM).

The original nozzle which was manufactured with a 0.020 in drill bit.

It can be seen by both the SEM and an optical microscope that the hole is certainly not circular.

Shown left is the setup built during the summer of 2009 to measure the diameter of an opaque jet for the purpose of determining the flow velocity. Various light sources were tested to determine the optimal lighting conditions. Of three light sources, halogen lamp, red/green lasers and a 20W LED source, the 20W LED source provided the most intensity and least diffraction and non-uniformity in captured images.

A sample image captured using a green laser with a diverging lens as a light source. Diffraction is evident and was eventually eliminated by using an equally intense poly-chromatic light source (20W LED).

The interactions of a liquid jet between a moving surface are eventually studied using a nozzle placed above a high speed projectile.

A stopping mechanism was needed for this projectile so I designed and built one which uses friction to dissipate the energy of a 2.5kg projectile moving at at 90+km/hr.

Shown to the left is the manufactured brake pad mount and its associated CAD drawing below.

(Left) CAD drawings of the projectile and the catcher.