History of Coherent Jet Nozzles

The Center for Grinding Research and Development (CGRD) at the University of Connecticut pioneered coherent jet nozzles in 1992, in a project funded by the USAF, with Pratt and Whitney as the customer. CGRD was set up by Trevor Howes and John Webster in 1989, as a National Science Foundation Industry/University Cooperative Research Center. The definition of coherency was based on the dispersion of the jet at a distance of 12 inches (30 centimetres) from the nozzle tip. A very coherent jet is one that doubles in diameter or thickness over that distance. Coherency increases the jets ability to remove the air barrier through a more concentrated impact energy, and excludes driving additional air into the structure of the wheel. Chuanliang Cui presented his PhD research on nozzle geometry, factors affecting coherency, and the effect on hydrodynamic pressure, in 1995. Richard Mindek presented his PhD research on the optimization of flowrate and pressure of coolant application in creep feed grinding in 1998. In 1998 John Webster left CGRD and joined Saint Gobain. In the six year period that followed, the value of coherent jet nozzles, at optimum flowrate and pressure, was successfully tested in many industrial grinding application at customers of Saint Gobain. In 2004 Cool-Grind Technologies was launched with the mission of making coherent-jet nozzles more readily available, and with greater range of adjustment and greater operator acceptance.