Diffuser (thermodynamics)

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

Aircraft intake method

Abstract: An aircraft turboshaft engine intake includes an axial diffuser and a colinear plenum disposed in flow communication therewith for collecting diffuser air therefrom. A scroll is disposed radially below the plenum in flow communication therewith for accelerating the plenum air for discharge to the aircraft engine. In this arrangement, propeller air is diffused in the diffuser and collected in the plenum wherein it is turned radially inwardly and accelerated through the scroll into the, engine. Diffusion is uncoupled from air turning for improving the efficiency thereof.

Aircraft engine pitot plenum intake

Abstract: An aircraft turboshaft engine intake includes an axial diffuser and a colinear plenum disposed in flow communication therewith for collecting diffuser air therefrom. A scroll is disposed radially below the plenum in flow communication therewith for accelerating the plenum air for discharge to the aircraft engine. In this arrangement, propeller air is diffused in the diffuser and collected in the plenum wherein it is turned radially inwardly and accelerated through the scroll into the engine. Diffusion is uncoupled from air turning for improving the efficiency thereof.

Numerical Investigation of a First Stage of a Multistage Centrifugal Pump: Impeller, Diffuser with Return Vanes, and Casing

Abstract: This paper deals with the numerical investigation of a liquid flow in a first stage of a multistage centrifugal pump consisting of an impeller, diffuser with return vanes, and casing. The continuity and Navier-Stokes equations with the turbulence model and standard wall functions were used. To improve the design of the pump's first stage, the impacts of the impeller blade height and diffuser vane height, number of impeller blades, diffuser vanes and diffuser return vanes, and wall roughness height on the performances of the first stage of a multistage centrifugal pump were analyzed. The results achieved reveal that the selected parameters affect the pump head, brake horsepower, and efficiency in a strong yet different manner. To validate the model developed, the results of the numerical simulations were compared with the experimental results from the pump manufacturer.

Unsteady flow investigation in rotor-stator interface of a radial diffuser pump

Abstract: The flow in a vaned diffuser radial pump is fully turbulent and strongly unsteady, caused by the rotor-stator interaction. In this paper, two-dimensional laser Doppler velocimetry (LDV) measurement results have been utilized to investigate the unsteady flow in a low specific speed radial diffuser pump with leaning impeller trailing edges. CFD simulations have been also conducted to provide more extensive results at different flow rates. The analysis has been mainly focused on the flow in the radial gap region between the impeller and diffuser where the unsteady interaction is the strongest. The velocity and turbulence fields are detailedly examined and quantitatively compared between CFD and LDV as well. In addition, the downstream effect from the impeller rotation has been compared between the leaning and normal trailing edges of the impeller.

Calculated Design Data for the Multiple-Disk Pump Using Incompressible Fluid

Abstract: Earlier analyses of the laminar radically outward flow of Newtonian incompressible fluid between parallel corotating disks have been used to calculate the performance of multiple-disk pumps using such flow passages as the rotor. Such pumps are characterized by certain dimensionless parameters and a large number of computerized calculations have enabled preparation of pump performance maps for pumps idealized as having no losses external to the rotor; these maps show the quantitative dependence of pump efficiency, pressure change and required power on the pump geometry, speed, and on fluid properties. Conventional loss information for the pump entrance and diffuser flows, and conventional bearing, seal, and “disk friction” loss information, must be applied in the design process to provide prediction of actual pump performance and comparison with conventional pumps. The design information is also applicable to low-pressure gas blowers.