화학공학소재연구정보센터
Atomization and Sprays, Vol.25, No.11, 1013-1024, 2015
DYNAMICS OF CLEANING BY HYDRAULIC PULSED JET
Because of its cleaning and cutting capabilities, hydraulic pulsed jet technology is considered to be a highly efficient method for improving the rate of penetration. Although adequate removal of cuttings from the bottom hole is important for efficient drilling operations, very little basic research is available concerning the fundamentals of chip removal by the hydraulic pulsed jet. Therefore, this paper presents a discussion of a numerical simulation investigation for the performance of a pulsed jet in removing loose particles. The cleaning effects of a pulsed jet and continuous jet were compared, and the parametric influence analysis of particle size, frequency, and nozzle size was performed. The results show that the cleaning effect of the pulsed jet is better than that of the continuous jet under the same conditions, especially for larger particles. Under the given conditions, the relatively low-frequency pulsed jet (about 10 Hz) is more efficient to remove chips. The cleaning effect of the pulsed jet improves with the growth of the particle size and nozzle size. The system studied in the paper is not directly applicable to a real drilling bit. However, the work done with such a simplified system can provide a better understanding of the process of chip removal by the pulsed jet, and the influencing parameters. This work may also provide a reasonable basis for the use of pulsed jet methods in drilling.