The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	An investigation of the dynamics of abrasive waterjet formation
Author:	Khan, Md. Ekramul Hasan
View Online:	njit-etd1990-016 (x, 163 pages ~ 8.2 MB pdf)
Department:	Department of Mechanical and Industrial Engineering
Degree:	Master of Science
Program:	Mechanical Engineering
Document Type:	Thesis
Advisory Committee:	Geskin, E. S. (Committee chair) Chen, Rong-Yaw (Committee member) O'Brien, Keith T. (Committee member)
Date:	1990
Keywords:	Water-jet. Jet cutting.
Availability:	Unrestricted
Abstract:	The aim of this research was to investigate the jet formation and the jet behavior, as characterized by the velocity field, the force exerted by the jet on a work-piece and the jet geometry. The velocity and force distributions were measured using a laser transit anemometer (LTA) and a piezoelectric force transducer (PFT) respectively for constant water pressure (334.6 MPa) supply. The jet structure and its instantaneous behavior were visualized by the used of high speed filming. LTA and PFT measuring techniques were established and verified. The measurements were performed under different operating conditions. It was found that at a constant pressure, 1. The sapphire nozzle diameter is a principle process variable. 2. The addition of abrasives substantially decreases the water velocity. 3. The force distribution has a peak about 8-20mm from the nozzle tip. 4. The flow discontinuity causes particle accumulation. 5. Ring vortices are present at the boundary of the waterjet but for abrasive waterjet the vortices break away. 6. Increasing the carbide diameter, or abrasive flow, or decreasing the abrasive size causes an increase of overall jet diameter.