Performance Study Of A Regenerative Flow Compressor As A Secondary Air Pump For Engine Emission Control

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A six-stage axial-flow compressor with a tip speed of 550 feet per second and a flat operating characteristics at constant speed has been designed and tested. It was designed for a constant power input per pound of flow in expectation that this would result in a wider mass-flow operating range at a given stagnation-presssure ratio. The design specific weight flow was 21.3 pounds per second per square foot of frontal area at atmospheric discharge with a stagnation-pressure ratio of 3.25 and an inlet hub-tip radius ratio of 0.7. Several configurations consisting of various blade setting angles and solidities were tested. Tests showed that the design flow, pressure ratio, and flat operating characteristic were obtained over a range of 10 percent of design flow at a peak efficiency of 82 percent for design conditions. The compressor had a possible immediate application for air removal from a large slotted-throat transonic wind tunnel, but the design theory could apply to any low-speed industrial compressor or second spool of a turbojet engine.

The NACA has conducted an investigation to determine the performance that can be obtained from a multistage axial-flow compressor based on airfoil research. A theory was developed; an eight-stage axial-flow compressor was designed, constructed, and tested.

The primary human activities that release carbon dioxide (CO2) into the atmosphere are the combustion of fossil fuels (coal, natural gas, and oil) to generate electricity, the provision of energy for transportation, and as a consequence of some industrial processes. Although aviation CO2 emissions only make up approximately 2.0 to 2.5 percent of total global annual CO2 emissions, research to reduce CO2 emissions is urgent because (1) such reductions may be legislated even as commercial air travel grows, (2) because it takes new technology a long time to propagate into and through the aviation fleet, and (3) because of the ongoing impact of global CO2 emissions. Commercial Aircraft Propulsion and Energy Systems Research develops a national research agenda for reducing CO2 emissions from commercial aviation. This report focuses on propulsion and energy technologies for reducing carbon emissions from large, commercial aircraftâ€" single-aisle and twin-aisle aircraft that carry 100 or more passengersâ€"because such aircraft account for more than 90 percent of global emissions from commercial aircraft. Moreover, while smaller aircraft also emit CO2, they make only a minor contribution to global emissions, and many technologies that reduce CO2 emissions for large aircraft also apply to smaller aircraft. As commercial aviation continues to grow in terms of revenue-passenger miles and cargo ton miles, CO2 emissions are expected to increase. To reduce the contribution of aviation to climate change, it is essential to improve the effectiveness of ongoing efforts to reduce emissions and initiate research into new approaches.