Diffuser (thermodynamics)

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

CFD computations of steady and non-reactive flow around fin-guided ram projectiles

Abstract: The numerical simulation of the flow around the body has been conducted with the Navier-Stokes code TASCflow, used in a non-reactive, steady and three-dimensional version. The aim of this computational work is to contribute to the projectile shape optimization under pure aerodynamical conditions, and therefore, to localize shock waves and their interactions, recirculation zone and high-temperature areas. Results presented in this paper show the effects of the fins on the flow configuration around the body and at the base (recirculation zone). Parameters such as the profile of leading edges and the number and size of fins are taken into account to compare the different flow fields. The results of computation, related to experiments performed in inert gas with different projectiles, have been used to highlight the influence of these parameters on the efficiency of the diffuser formed by the projectile afterbody. The pressure and temperature in the flow around the projectile when entering the ram tube and just before the initiation of the combustion are given. The present work demonstrates that the computer code TASCflow can provide a valuable tool for the optimization of the projectile geometry.

Numerical and experimental research on different inlet configurations of high speed centrifugal compressor

Abstract: Three different inlet configurations, including a original straight pipe and two bend pipes with different axial length, for a high speed low mass flow centrifugal compressor were modeled with whole blade passages and simulated unsteadily by 3D viscous Navier-Stokes equations. The performance disparities of compressor stage were tested and verified by experiments in which dynamic pressure data acquisition of internal flow field was performed. As the result shows, the choke point decreases to lower mass flow rate due to the distortion caused by bend-pipe inlet and is aggravated as the rotation speed increases. The distortion effect spreads circumferentially in impeller and makes the flow structure varied. The longer axial distance bent inlet leads to larger radial distortion and heavy blockage at mid-span under large mass flow mainly causes compressor choke margin narrowed. Bend pipe distortion brings an impact up to diffuser on unsteady pressure pulsation caused by blades sweep and the impact appears more powerful when it is closer to volute tongue.

Actuator for a heating/cooling diffuser

Abstract: A diffuser (20) is provided with three discharges (26) (27) (28). Two of the discharges (27) (28) are directed in one direction and, when installed, would be directed towards the outside wall (102) of the conditioned space. The other discharge (26) is directed in the opposite direction and would discharge into the interior of the conditioned space. Responsive to the temperature of the conditioned air being supplied, a thermally responsive actuator is in either one of two positions whereby either one of the two discharges in the one direction or the discharge in the opposite direction is blocked. This results in two discharges in one direction or one in each direction with the discharge area being the same in both instances.

Power gas burner

Abstract: A gas burner produces a homogeneous mixture of gas and air in a short mixing zone by creating turbulence to promote thorough mixing. The burner includes a burner housing supporting a gas distribution tube and an air blower, the distribution tube emitting jets of gas in a radial direction and supporting a baffle plate having a plurality of openings. Air from the blower impinges on the jets of gas to form streams of gas and air that pass through the openings in the baffle plate. A diffuser ring is disposed downstream from the baffle plate and extends radially inward to form a flow constriction. The streams of gas and air contact the diffuser ring and undergo turbulence and the resulting mixture of gas and air passes through the diffuser ring and expands within the interior of a perforated combustion head. The mixture passes through the perforations and when ignited obtains combustion of nearly 100% of the gas and produces a very even flame profile. The burner is easy to manufacture and operates well at very low gas pressures.

Ventilator for automobiles has hollow body, fitted with single unit, which acts as closing device, operating control and director for air flow.

Abstract: The ventilator consists of a hollow body, fitted in the passenger compartment at the outlet end of an air pipe. The body is provided with an air diffuser, which defines the air flow, a closing element, operated by a control, and a device for directing the flow of air. The closing element (13) is integrated with its control and with the element for directing the flow.