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Showing 1 to 15 of 15 for “"ejectors"”.
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Compressible Flow Analysis of Thrust Augmenting Ejectors
… the thrust augmenting characteristics of jet ejectors. The mixing process in ejectors can be analyzed using either the control volume approach, or detailed models based on the Navier -Stokes Equations and the theory of turbulent jets. The control volume approach uses integrated forms of the …
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Head augmentation in hydraulic turbines by means of draft tube ejectors
… turbines which utilize excess flow in draft tube ejectors to increase the effective head across the turbine. The resulting reduction in system cost was found to exceed the corresponding reduction in capacity. The use of draft tube ejectors was found to require slightly lower turbine settings due …
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Numerical Examination of Flow Field Characteristics and Fabri Choking of 2D Supersonic Ejectors
An automated computer simulation of the two-dimensional planar Cal Poly Supersonic Ejector test rig is developed. The purpose of the simulation is to identify the operating conditions which produce the saturated, Fabri choke and Fabri block aerodynamic flow patterns. The effect of primary to …
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Numerical Investigation of Mixing Tabs in Multi-Ring Entraining Diffuser in Air-Air Ejectors
… entraining diffusers in subsonic short air-air ejectors. Although numerous studies exist on mixing tabs in nozzles, none was found that placed tabs in an entraining diffuser system used with an ejector. Given that mixing tabs led to improvements at the nozzle, they were analyzed in entraining …
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Testing and modeling of a two-phase ejector
… performed as well as typical single-phase ejectors, an improvement of 12% could be achieved. Previous tests have demonstrated a smaller 3.7% improvement; the difference is in the poor performance of the two-phase ejector. The purpose of this research is to understand the operating …
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Saturation curve analysis of humidification-dehumidification desalination systems and analysis of reversible ejector performance
… definition of different performance metrics for ejectors are analyzed and compared. Graphical illustrations are provided to support intuitive understanding of these metrics. The performance metrics are applied to existing experimental data. The behaviour of reversible ejectors is investigated. …
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Experimental and numerical investigation of the design and control of vapor-compression systems with integration of two-phase ejectors for performance enhancement through expansion work recovery
The use of ejectors to improve the efficiency and capacity of vapor-compression refrigeration cycles by means of expansion work recovery has received significant attention in the past decade. Research has focused primarily on the design and performance of the ejector and the effect the ejector has …
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Analytical and experimental investigation of two-phase ejector cycles using low-pressure refrigerants
… compared to CO2. It was found that two-phase ejectors using these lowpressure working fluids were able to recover similar but lower fractions of the total expansion work available for recovery, compared to two-phase ejectors using CO2. The alternate ejector cycle was compared to an expansion …
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Experimental investigation of vortex tube and vortex nozzle for applications in air-conditioning, refrigeration, and heat pump systems
… which is possibly applicable to two-phase ejectors used in vapor compression cycles. This new control mechanism has the advantages of being simple and potentially less costly. It can also possibly avoid the additional frictional losses of previously proposed ejector control mechanisms using …
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Vortex control of two-phase refrigerant flow in nozzles and its application in ejector vapor compression cycles
… performance when the vortex nozzle is used in ejectors. The vortex nozzle divergent part length as well as the divergent angle seem to be the most important geometric parameters that need to be appropriately sized in order to achieve satisfactory vortex control range and high nozzle isentropic …
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Experimental Investigation and Modeling of Scale Effects in Micro Jet Pumps
… for two classes of microscale jet pumps: jet ejectors and jet injectors. These components pump fluids with no moving parts and can be integrated into Power MEMS devices to satisfy pumping requirements by supplementing or replacing existing solutions. This thesis presents models developed from …
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Geoejector : extracting geothermal fluid from a low-pressure geothermal well
… in many industries. However, unlike traditional ejectors, it is faced with challenges involving two-phase geothermal fluids and highly variable inflow conditions. From analysis with an analytical and numerical model of the subsonic geoejector, it was found that it cannot accelerate the …
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A Computational Model for Two-Phase Ejector Flow
… model to simulate two-phase flow in refrigerant ejectors is described. This work is part of an effort to develop the ejector expansion refrigeration cycle, a device which increases performance of a standard vapor compression cycle by replacing the throttling valve with a work-producing ejector. …
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Potentials for COP increase in vapor compression systems
… in vapor compression systems: work recovery ejectors, condenser subcooling and increase of relative size of heat exchangers (HXs). Regarding work recovery ejectors, experimental results showed that the COP of the ejector system increased between 8.2% and 14.8% when compared to a conventional …
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The computer modelling and experimental study of confined jet mixing with application to jet pump design
… duct typically used in jet pumps and ejectors has been undertaken. A so-called Prandtl-Kolmogorov two-equation turbulence model, with turbulent kinetic energy k and turbulent energy dissipation rate E as the two parameters, is incorporated into the time-mean Navier-Stokes equations to …