Self resonating pulsed water jets for aircraft coating removal: Feasibility study

The objective of this project was to investigate the feasibility of disrupting a high pressure water jet into a discrete train of well organized slugs through passive acoustic self-excitation of the jet, and as a result to enhance the ability of the jet to remove aircraft coatings and to prepare surfaces for recoating. This innovative technique takes advantages of the water hammer pressures produced by the slugs' impact (which are much higher than the stagnation pressures generated by a continuous jet), without the drawbacks of having a mechanical rotating interrupter. In addition this technique provides larger working standoff distances, wider areas of impact and thus greater control of the energy imparted to a target than a cavitating jet. It is therefore capable of overcoming the drawbacks of existing water jet methods in preparing aircraft surfaces for repainting and of providing a primary supplement if not a practical replacement for chemical removal methods.