Consumption of sand tube during waterjet work

Waterjet cutting is very hard. The mold of the waterjet is an "L" shaped "tubular" object. The water will impact the wall of the L-bend during the process of turning through the L-bend and cause the loss of the mold. The non-wearing of the waterjet can be explained by the viscous phenomenon. Due to the existence of the viscous force, the flow rate of water increases with the distance from the wall of the pipe. Nothing serious. Secondly, the friction of the waterjet is mainly from the sand inside, and the coefficient of viscosity between the sand and the water is so large that the sand is more easily driven by the water, so as to achieve a higher speed, and the water with a higher speed In the center of the pipeline, the sand particles generally do not touch the pipe wall, so the wear is minimized.
Another question is: Did the exit give him any force to increase its exit speed when the water column was shot, and then the strength also increased? The pressure at the water outlet of the waterjet is above 50 MPa, which is equivalent to the pressure generated by placing a 5 kg object on an area of 1 mm2. Under such a large pressure, when the supersonic water flow hits the processed material, its speed will drop sharply due to the sudden obstruction, and the pressure will suddenly increase, resulting in a huge The impact force causes brittle fracture on the extremely small area of the processed part, so as to achieve the purpose of cutting the workpiece. If grinding materials such as silica are added to the water, the cutting ability of the water jet will increase exponentially, and its processing effect is significantly better than cutting the workpiece with a metal cutter. It can process complex profiles and parts cut along arbitrary curves that cannot be processed with metal tools. In the process of processing, not only the incision of the workpiece processed by the "waterjet" is neat and smooth, there is no problem of rough edges, delamination, tearing, deformation, etc., but almost all the heat generated during the work can be taken away by the water. At the same time, during the cutting process, the vibration and noise caused by the "waterjet" are very small, and the small amount of chips generated will also flow away with the water, and there will be no flying chips.