The Hydro Dynamics pump used cavitation and shock waves from a dimpled rotor spinning inside a housing to increase the temperature of water flowing through the device. It was tested on a number of occasions to be OU, but not reliably. Rothwell has reported on it. It is in production now and has been for years but they do not claim OU - only high efficiency.
In contrast, cavitation in the Rossi device could be a function of magnetostriction on the nickel powder combined with water flow. The outer surface of the reactor would be the functional equivalent of a transducer to cavitate the water flowing over it. IOW the nanopowder would function like a humming transformer core and it could also operate internally in the same way on hydrogen in the reactor - double duty, in effect. Like the Griggs pump, cavitation generates shock waves which convert mechanical energy into heat energy in a way that seems to be gainful at times. I'm not sure if it is magic or supermagic. From: Stephen A. Lawrence > If Rossi has found a way to get multiple kilowatts of energy out of a 1 HP pump motor, while still drawing off enough energy to keep the water moving, I say more power to him. That would be every bit as remarkable -- and valuable -- as getting multiple kilowatts of energy out of a nickel/hydrogen reaction. He wouldn't be the first - you are familiar with the Griggs pump, no? http://www.rexresearch.com/griggs/griggs.htm
