Diffuser (thermodynamics)

About: Diffuser (thermodynamics) is a research topic. Over the lifetime, 6731 publications have been published within this topic receiving 54738 citations.

Small diameter gas turbine engine

Abstract: The diameter of a gas turbine engine may be reduced through the use of a construction including a monorotor (44) journaled for rotation and mounting compressor blades (48) at one end (46) and turbine blades (56) at an opposite end (54). An axial diffuser (96) receives the discharge from the compressor blades (84) and is contained in a plenum (98). A reverse flow, annular combustor (83) is disposed about the rotor (44) and has a dome (100) whose height is a minor fraction of the axial length of the combustor (83) and which discharges to an annular turbine nozzle (77) having axial turbine nozzle blades (76).

Conical diffuser tip

Abstract: A catheter assembly (10) is provided having a conical diffuser tip (18) for use in rapid infusion procedures. The conical diffuser tip provides a flared opening whereby the velocity of an infusant is decreased as the infusant travels through the catheter tip and exits into the vascular system of a patient. This decrease in velocity proportionately reduces the backpressure and/or recoil force of the catheter assembly thereby permitting the use of higher infusion rates. The catheter tip is introduced into the vasculature of a patient via a splittable introducer needle.

Gas turbine engine and a diffuser therefor

Abstract: A gas turbine engine with first and second axial flow compressors and an intercooler therebetween is provided with a bend diffuser and a radial flow diffuser to diffuse the air leaving the downstream end of the first axial flow compressor at a first radial distance from the axis to the upstream end of the intercooler at a second radial distance from the axis. The bend diffuser comprises a first radially outer wall and a second radially inner wall. The first wall is elliptical and the second wall has a profile derived from a relationship between the local area ratio and the path length around the arc such there is rapid diffusion in the bend diffuser without fluid flow separation from the first wall.

Radial flow compressors

Abstract: A radial flow compressor is described in which the diffuser entrance is uniquely contoured to minimize losses attributable to the differences in absolute flow angle of the high velocity air discharged from the compressor impeller, such differences existing across the width of the impeller discharge flow path. The diffuser comprises a plurality of vanes which split the circumferential impeller discharge into discrete, tangential, diffusion channels. Each vane is wedge shaped and has suction and pressure surfaces on opposite sides of the leading edge thereof. The leading edge is angled, or swept, relative to the direction of air flow. The suction surface is angled relative to the impeller axis so that, marginally of the leading edge, it is more tangential at the shroud side of the flow path then at the hub side thereof and an essentially uniform impingement angle of approximately 0* is obtained along the width of the suction surface.

A Meanline Model for Impeller Flow Recirculation

Abstract: Flow recirculation at the impeller inlet and outlet is an important feature that affects impeller performance, especially the power consumption at a very low flow rate. Although the mechanisms for this flow phenomenon have been studied, a practical model is needed for meanline modeling of impeller off-design performance. In this paper, a meanline recirculation model is proposed. At the inlet, the recirculation zone acts as area blockage to relieve the large incidence of the active flow at a low flow rate. The size of the blockage is estimated through a critical area ratio of an artificial “inlet diffuser” from the inlet to throat. The intensity of the reverse flow can then be calculated by assuming a linear velocity profile of meridional velocity in the recirculation zone. At the impeller outlet, a recirculation zone near the suction surface is established to balance the velocity difference on the pressure and suction sides of the blade. The size and the intensity of the outlet recirculation zone is assumed related to blade loading, which can be evaluated based on flow turning and Coriolis force. A few validation cases are presented showing a good comparison between test data and prediction by the model.Copyright © 2008 by Concepts ETI, Inc.