Abstract: A method of controlling superplastic forming where a sheet of material is subjected to superplastic forming when in a chamber of a forming apparatus having a supersonic fluidic oscillator (SFO) includes determining maximum and minimum limits for a ratio of supply pressure applied to the SFO related to forming pressure, where the application of supply pressure to the SFO in a manner that maintains the ratio between the maximum and minimum limit causes the SFO to generate continuous, uninterrupted, gas oscillations; with a supply pressure sensor, detecting the gas pressure supplied to the SFO and transmitting it to a controller; with a forming pressure sensor, detecting the forming pressure within the chamber and transmitting it to the controller; and operating the controller to maintain the pressure supplied to the SFO to maintain the ratio of the detected supply pressure to the detected forming pressure between the maximum and minimum limits.

Abstract: A method of forming a material using a supersonic fluidic oscillator in a superplastic forming process and a related system. Pressurized gas, at a baseline pressure, is applied to a surface of the material when the material is received within a cavity of a forming tool. Pressure fluctuations, relative to the baseline pressure within the tool cavity, are created with a supersonic fluidic oscillator. Each pressure fluctuation (i) deforms the material and (ii) subsequently allows for a partial stress relief of the material during the forming process.

Abstract: A method of forming a material using a supersonic fluidic oscillator in a superplastic forming process and a related system is provided. The method comprises applying pressurized gas at a baseline pressure to a surface of the material when the material is received within a cavity of a forming tool, and creating pressure fluctuations with a supersonic fluidic oscillator relative to the baseline pressure within the tool cavity. Each pressure fluctuation (i) deforms the material and (ii) subsequently allowing for a partial stress relief of the material during the forming process.

Abstract: An exhaust gas recirculation (EGR) system for use in a four-stroke, internal combustion, compression-ignition engine having at least one engine cylinder, at east one combustion chamber, at least one intake valve and a crankshaft. The EGR system includes at least one exhaust gas intake valve that is opened during at least a portion of an engine intake stroke when the exhaust gas pressure is greater than the pressure of gas in the combustion chamber, thus allowing exhaust gas to flow into the combustion chamber to establish internal EGR. A cam-operated intake rocker arm assembly has the form of both a first class lever and a second class lever. The first class lever directly communicates motion of the intake rocker arm assembly to open the intake valve, and the second class lever communicates motion of the intake rocker arm assembly through a hydraulic transfer assembly to open the exhaust gas intake valve.