Gas compressor

About: Gas compressor is a research topic. Over the lifetime, 91817 publications have been published within this topic receiving 552209 citations.

Control of Shock Structure and Secondary Flow Field Inside Transonic Compressor Rotors Through Aerodynamic Sweep

Abstract: The present paper reports a numerical study on the effects of aerodynamic sweep applied to a low-aspect-ratio, high-through-flow, state-of-the-art, axial transonic compressor design. Numerical analyses based on the Reynolds-averaged Navier-Stokes equations were used to obtain the performance of a conventional unswept rotor, a forward swept rotor, and an aft-swept rotor, at both design and off-design operating conditions. The numerical analyses predicted that the forward-swept rotor has a higher peak efficiency and a substantially larger stall margin than the baseline unswept rotor, and that the aft-swept rotor has a similar peak efficiency as the unswept rotor with a significantly smaller stall margin. The rig test confirmed the numerical assessment of the effects of aerodynamic sweep on the low-aspect-ratio, high-through-flow, transonic compressor rotor. Detailed analyses of the measured and calculated flow fields indicate that two mechanisms are primarily responsible for the differences in aerodynamic performance among these rotors. The first mechanism is a change in the radial shape of the passage shock near the casing by the endwall effect, and the second is the radial migration of low-momentum fluid to the blade tip region. Aerodynamic sweep can be used to control the shock structure near the endwall and the migration of secondary flows and, consequently, flow structures near the tip area for improved performance.Copyright © 1998 by ASME

Energy-efficient all-electric ECS for aircraft

Abstract: The invention is an energy-efficient all-electric environmental control system (70). The system includes a cabin compressor (16) and a Freon compressor (14), both of which are commonly driven by a two-speed electric motor (12). The motor (12) operates at low speed at low altitudes and on the ground to drive the Freon compressor (14). Freon fluid then cools the electric motor (12) and the cabin (18) and avionics (56) by means of the evaporator dehumidifier systems (72) and (74), respectively. At high altitudes the electric motor (12) runs at high speed to drive the cabin compressor (16) to provide pressurization for the cabin (18). In this operation mode, the Freon compressor can be disconnected via an electromagnetic clutch (48). The ECS (70) also includes a liquid Freon pump (52) which can be utilized when the Freon compressor is disconnected or bypassed to circulate liquid Freon to cool the electric motor (12) and to circulate through the evaporators (38) and (76). The pump (52) is driven by an ac or dc motor (54).

Method of air-flow measurement and active operating limit line management for compressor surge avoidance

Abstract: A transfer function between the inlet air-flow consumed by a Gas Turbine engine, and the engine parameters of speed, pressure ratio, and Inlet Guide Vane (IGV) angle is described. An active compressor Operating Limit Line (OLL) management strategy that leverages this improved flow measurement transfer function is also described. The improved flow measurement capability afforded by the transfer function permits a deterioration in flow rate caused by compressor fouling to be detected. Using the deterioration in flow rate as a proxy for compressor fouling, a degraded surge boundary associated with fouling can be predicted, using a transfer function between degradation of air-flow along operating line and degradation of surge line. In combination, the inventive improvements in flow measurement and operating line management afford added compressor surge protection across the operating range, while permitting the attainment of elevated pressure ratios associated with high thermodynamic efficiency and output.

Gas turbine engine with water injection

Abstract: Precompressor and pre-booster water spray injection apparatus and methods are described. In an exemplary embodiment, a gas turbine engine suitable for use in connection with water spray injection includes a low pressure compressor, a high pressure compressor, and a combustor. The engine also includes a high pressure turbine, a low pressure turbine, and a power turbine. A water injection apparatus is provided for injecting water into an inlet of the high pressure compressor. The water spray injection apparatus is in flow communication with a water supply, and during engine operation, water is delivered from such supply through the injection apparatus to the inlet of the compressor.