Diffuser (thermodynamics)

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

Canonical Normal Shock Wave/Boundary-Layer Interaction Flows Relevant to External Compression Inlets

Abstract: The normal shock wave/boundary-layer interaction is important to the operation and performance of a supersonic inlet, and the normal shock wave/boundary-layer interaction is particularly prominent in external compression inlets. To improve understanding of such interactions, it is helpful to make use of fundamental flows that capture the main elements of inlets, without resorting to the level of complexity and system integration associated with full-geometry inlets. In this paper, several fundamental flowfield configurations have been considered as possible test cases to represent the normal shock wave/boundary-layer interaction aspects found in typical external compression inlets, and it was found that the spillage diffuser more closely retains the basic flow features of an external compression inlet than the other configurations. In particular, this flowfield allows the normal shock Mach number as well as the amount and rate of subsonic diffusion to all be held approximately constant and independent of ...

Development of a diffuser/nozzle-type micropump based on magnetohydrodynamic (MHD) principle

Abstract: This paper reports a research effort to microfabricate a nozzle-diffuser type of micropumps based on the magnetohydrodynamic (MHD) principle using LIGA technologies. The micropump is driven using the Lorentz force and can be used to deliver electrically conductive fluids. The major advantage of a MHD-based micropump is that it does not contain any moving parts. It may have potential applications in medicine delivery, biological and biomedical studies. Prototypes of MHD micropumps have been fabricated and tested. Significant bubble generation was observed due to electrolysis effect. These bubbles made the flow two-phase one and resulted in flow rate reduction. To overcome bubble generation, a new generation of MHD micropumps is currently under development. This new, diffuser/nozzle type of the MHD micropumps is based on the similar design as widely used in the diffuser/nozzle pumps with diaphragm.

Study of the different parameters that influence on the performance of water jet pump

Abstract: The aim of this study is to investigate the performance of water jet pump. This study is reported in a series of three papers. In this paper, the performance of water jet pump was studied. The effects of the pump operating conditions and geometries on its performance were investigated. The experimental rig was constructed such a way it can be changing the driving nozzle, mixing chamber and diffuser. During experimental program water is used in both motive and pumped sides. In this study three different diameters of driving nozzles, namely (10, 12.7 and 16 mm) have been used with one mixing chamber of 25.4 mm diameter (i.e. three different area ratios of 0.155, 0.25 and 0.4). Furthermore three different mixing chamber lengths to mixing chamber diameter ratio of 6.75, 7.25 and 7.86. And three different diffuser angles of 4 o , 5.5 o and 7 o respectively with one suction nozzle of semi cone angle of 22 o . The effect of nozzle to throat spacing to nozzle diameter ratio "X" with values of 0 D, D, 1.5 D and 2 D, on the jet pump performance was also tested under different flow rates and motive pressures. In all cases, it was found that the best efficiency for the jet pump is attained with "X" equal one, and the best values for these design parameters have been obtained from the experimental work. The performance of slurry jet pump and the comparison between them will later be discussed in another further paper.

Systems and methods of providing high pressure air to a head end of a combustor

Abstract: A combustor includes a first flow path and a second flow path. The first flow path places a diffuser in indirect fluid communication with a combustor cap assembly by way of an intervening lower combustor annular passageway. The second flow path places the diffuser in direct fluid communication with the combustor cap assembly.

PIV Investigations of the Flow Field in the Volute of a Rotary Blood Pump

Abstract: A full-size acrylic model of a rotary blood pump was developed in order to utilize Particle Image Velocimetry (PIV) to make measurements of the fluid velocities and turbulent stresses throughout the device. The development of an understanding of the hemodynamics within the blood pump is critical to the development and validation of computational models. A blood analog solution, consisting of sodium iodide solution and glycerin, was developed to match physiological kinematic viscosity. The refractive indecies of the fluid, the pump casing and the impeller were matched to facilitate the use of PIV to make velocity measurements. Velocity measurements made in the volute exit/diffuser region are presented for pumps speeds of 3000-3850 rpm. At each speed data were obtained at a physiological pressure of 90 mmHg and at a maximum flow condition. Four hundred data pairs were used for each resultant mean velocity vector value, representing greater than an order of magnitude more data pairs than reported previously in the literature on similar devices and resulting in velocity uncertainty levels of approximately ±2.9%.