Abstract: The main and ancillary factors which influence the oscillating cavity forming self-excited oscillation through the experiment is studied in this paper. The oscillators were compared and optimum seeked under the condition of experiment, based on which, the experimental research with leading- in turbulence were done. The purpose of the experiment is to supply a new thought for the design of drilling bit cavity, especially, it supplies the experimental evidence for the hydraulic system design of the small size cone bit. At the same time, the effort is made to find a new method of the fluid self - excited oscillating pressure boost.We adopted the replaceable oscillating cavity designed by authors in the experiment was adopted, it has three kinds of cavity diameters (50mm, 60mm, 70mm), and its cavity length can be steeples regulated. The experiment was done under the conditions of submergence by clean water and with no backpressure. In the case of submergence and freeness jet flow, the turbulence can be led-in by drilling a hole at the side wall of the oscillator, and the impact pressure of the jet flow can be measured at the outlet of the oscillator, then the experimental results can be analyzed through the waveform analysis and spectrum analysis. The experiment shows that the oscillator behaviors can be changed by leading- in turbulence, even possibly improved under some conditions. High power oscillator and producing self-excited pressure boost can form powerful impulse jet flow.

Key words: Jet drilling theory, Jet, oscillator, Perturbation, Laboratory testing, Experimental data