The Structure of High Speed Fluid Jets and Their Use in Cutting Various Soil and Material Types

This report describes an investigation into the effect of fluid additives upon the structure of high speed water jets, and the resulting change in the cutting ability of the jets when such additives are used. A literature review indicates that the effects of change in jet viscosity and surface tension upon jet structure are reduced with increase in jet velocity, and that while increasing jet viscosity improves jet cohesion, it reduces jet cutting ability. For this reason the study was directed towards the effect of viscoelastic additives, polymerized ethylene oxide and polyacrylamides, the results from which were compared with results from nonionic soaps and guar gum. The viscoelastic additives were found to give improved jet cohesion.