Diffuser (thermodynamics)

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

Automatic swimming pool cleaners and associated components

Abstract: Automatic swimming pool cleaning systems are disclosed. The systems include an automatic swimming pool cleaner (10) incorporating one or more curved wipers (30) protruding from its lower surface. The wipers (30) and flat bottom (34) of the cleaner (10) induce a vortex as fluid flows to its central inlet (50) entraining debris in the flow. A fluted throat (102A) surrounding the inlet (50) additionally assists the interior of the base of the cleaner (10) in retaining debris when opened for cleaning, additionally providing an improved flow path for enhanced debris pick-up. Also disclosed is a valve (200) useful for controlling and indicating the rate of fluid flow to a cleaner (10). Included within the valve (200) is a plunger (203) attached to a spring (202), with the spring force opposing fluid flow through the valve (200). Flow sufficient to overcome the spring force compresses the spring (202), however thereby moving the plunger (203) within the tube (201) and providing a dynamic indication of the rate of fluid flow. A diffuser (206) and fluid release ports (204A) permit the valve (200) to be adjusted to achieve a desired flow rate.

Axial flow gas turbine

Abstract: The cooling-air ducting of the axial flow gas turbine runs in the area of the last blading stage (9+14) radially inwards of the heat-accumulation segments (23, 24) inside the outer boundary of the rotor (4) and through blade root channels (21) in the blade roots of the last moving blade ring (9) and finally through a cooling-air blade ring (28) fixed to the rotor into the diffuser into which the cooling-air flow enters with a velocity vector which essentially corresponds to the average velocity vector of the exhaust-gas flow entering into the diffuser. This avoids the flow losses which occur when the cooling-air flow passes out into the exhaust-gas flow in the area of the last stage or stages. At the same time, the temperature difference between the rotor circumference and the last rotor disk (4), likewise cooled by tapped air from the compressor, is in this way reduced, as a result of which the thermal stresses in the rotor are also reduced.

Centrifugal fluid machine

Abstract: At a vaned diffuser or a volute casing of a centrifugal fluid machine, pressure pulsation and vibrating forces acting upon the diffuser or the volute casing are mitigated or cancelled so as to abate the noise from the centrifugal fluid machine. The fluid machine having an impeller 3 rotating about a rotating shaft 2 within a casing 1 and having a vaned diffuser 4 or volute 12 fixed to the casing 1 is constructed such that radius of the vane trailing edge of the impeller 3 and radius of the vane leading edge of the diffuser 4 or radius of the volute tongue is varied in the direction of axis of rotation and inclinations, on a meridional plane, of the vane trailing edge of the impeller 3 and the vane leading edge of the diffuser 4 or the volute tongue are set in the same orientation, thereby reduction in head and efficiency or occurrence of an axial thrust may be restrained to the extent possible to optimally abate the noise and pressure pulsation of the centrifugal fluid machine.

Low noise fan

Abstract: A collectorless vacuum fan for floor maintenance machines has a backplate with an inlet plate attached thereto in spaced relationship, and an impeller between the backplate and inlet plate Both the backplate and the inlet plate extend radially beyond the periphery of the impeller A shaft mounts the impeller for rotation The inlet plate has a central opening providing air to the hub of the impeller Vanes on the impeller discharge air out through a diffuser channel defined by the space between the inlet plate and the backplate outside the periphery of the impeller Attachment elements for mounting the inlet plate on the backplate leave the diffuser channel substantially unobstructed so that air is discharged about the entire periphery of the impeller The fan has increased air flow compared to a conventional fan having an integral collector housing and decreased noise compared to a fan having a 360 degree discharge and no diffuser

Mathematical Analysis for Off-Design Performance of Cryogenic Turboexpander

Abstract: A study has been conducted to determine the off-design performance of cryogenic turboexpander. A theoretical model to predict the losses in the components of the turboexpander along the fluid flow path has been developed. The model uses a one-dimensional solution of flow conditions through the turbine along the mean streamline. In this analysis, the changes of fluid and flow properties between different components of turboexpander have been considered. Overall, turbine geometry, pressure ratio, and mass flow rate are input information. The output includes performance and velocity diagram parameters for any number of given speeds over a range of turbine pressure ratio. The procedure allows any arbitrary combination of fluid species, inlet conditions, and expansion ratio since the fluid properties are properly taken care of in the relevant equations. The computational process is illustrated with an example.