ANALYSIS OF FLOW INSIDE THE FOCUSING TUBE OF THE ABRASIVE WATER JET CUTTING HEAD

摘要

To make the analysis of flow in the focusing tube of abrasive water jet cutting head, the calculation of interval of the exit velocities of water jet from the focusing tube into the free space is necessary. The calculation of longitudinal velocity in the axis of water jet at the exit from the focusing tube, the calculation of expansion velocity of water jet at its divergence in the air and the calculation of mean velocity of water jet at the end of the focusing tube are performed. For the calculations, it was necessary to determine a radius of jet at its exit from the focusing tube. The analysis of longitudinal velocity in the focusing tube of abrasive water jet cutting head serves to the determination of a negative pressure in the mixing chamber of the cutting head. The value of a negative pressure is one of the boundary conditions of mathematical modelling of water jet flow in the cutting head.