Abstract: A high performance muffler, e.g., for an internal combustion engine, reduces exhaust or other gas noise while maintaining a low backpressure to prevent engine power loss. A side inlet pipe connects gas to a muffler body. The inlet pipe is flared at its connection to the muffler body to direct flow of the gas through an inlet chamber of the muffler in a spiral path. In an example embodiment, the muffler body includes three chambers separated by panels. An inlet expansion chamber is adjacent to the inlet and includes a first pipe with a perforated portion. An intermediate expansion chamber adjacent to the inlet chamber receives the gas from the first pipe. Four small pipes at the exit end of the intermediate chamber extend into an outlet expansion chamber. The gas in the outlet expansion chamber exits the muffler body by an outlet pipe at the other end of the outlet expansion chamber. The muffler achieves a high sound reduction without increasing backpressure.

Abstract: The invention can be used in a micropump for dispensing a pharmaceutical liquid, in an ink jet printer or similar devices, or in other applications for controlled pumping of a liquid through an opening in a barrier wall. A pair of electrodes is in electrical contact with a fluid confined behind a containing wall. Each electrode is connected to a source of different electrical potential. When current is conducted through the fluid between the electrodes, resistance heating in the fluid causes local boiling and thus the formation and expansion of a bubble within the fluid. The electrodes are disposed on either side of an opening in the wall, so that the bubble is formed on one side of the wall in close proximity to the opening. Fluid behavior is such that a fluid jet is formed when the bubble collapses in close proximity to the wall. This jet impacts the bubble in a direction toward the wall.

Abstract: A high performance muffler, e.g., for an internal combustion engine, reduces exhaust or other gas noise while maintaining a low backpressure to prevent engine power loss. A side inlet pipe connects gas to a muffler body. The inlet pipe is flared at its connection to the muffler body to direct flow of the gas through an inlet chamber of the muffler in a spiral path. In an example embodiment, the muffler body includes three chambers separated by panels. An inlet expansion chamber is adjacent to the inlet and includes a first pipe with a perforated portion. An intermediate expansion chamber adjacent to the inlet chamber receives the gas from the first pipe. Four small pipes at the exit end of the intermediate chamber extend into an outlet expansion chamber. The gas in the outlet expansion chamber exits the muffler body by an outlet pipe at the other end of the outlet expansion chamber. The muffler achieves a high sound reduction without increasing backpressure.

Abstract: The invention can be used in a micropump for dispensing a pharmaceutical liquid, in an ink jet printer or similar devices, or in other applications for controlled pumping of a liquid through an opening in a barrier wall. A pair of electrodes is in electrical contact with a fluid confined behind a containing wall. Each electrode is connected to a source of different electrical potential. When current is conducted through the fluid between the electrodes, resistance heating in the fluid causes local boiling and thus the formation and expansion of a bubble within the fluid. The electrodes are disposed on either side of an opening in the wall, so that the bubble is formed on one side of the wall in close proximity to the opening. Fluid behavior is such that a fluid jet is formed when the bubble collapses in close proximity to the wall. This jet impacts the bubble in a direction toward the wall.

Abstract: A foldable obstacle system is provided on a hydraulic lifting body to alleviate cloud cavitation and so to reduce noise and surface erosion that might otherwise result from unsteady sheet cavitation and a re-entrant jet produced thereby. The system includes one or more foldable obstacle devices or plates, each of which is movable between a closed position at the surface of the body and an open position away from the body. When a re-entrant jet occurs, the jet acts to lift the plates and rotate them into the open position in which they block the re-entrant jet so as to reduce or prevent cloud cavitation. When cavitation does not occur, the normal fluid flow over the body acts to close and keep closed the obstacle devices or plates so that they do not interfere with the normal fluid flow.