A Jet Pump Design Theory

1960 ◽  
Vol 82 (4) ◽  
pp. 947-960 ◽  
Author(s):  
T. W. Van Der Lingen
Keyword(s):  
Design Theory ◽  
Momentum Equation ◽  
Operating Conditions ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Jet Pump ◽  
Pump Design ◽  
Jet Pumps ◽  
Pressure Recovery Factor ◽  
General Method

A compressible flow jet pump theory is evolved which can be more easily interpreted for design purposes than existing theories. It consists of a one-dimensional analysis based on the momentum equation and on complete mixing, used in conjunction with an over-all pressure recovery factor which is found experimentally. Tests on a small jet pump are described and from the results it is shown that the overall pressure recovery factor can be related to a single parameter in the analysis for all operating conditions of each general pump configuration. In this way a general method for the correlation of results and for the design of jet pumps is established.

DEGREE OF REGENERATION OPTIMIZATION FOR CYCLES OF MICROGAS TURBINE PLANTS

2020 ◽  
Vol 3 ◽  
pp. 59-66
Author(s):  
A.V. DOLOGLONYAN ◽  
V.T. MATVIINKO
Keyword(s):  
Mathematical Model ◽  
Heat Exchanger ◽  
Surface Area ◽  
Hydraulic Resistance ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Area Optimization ◽  
Pressure Recovery Factor ◽  
The Mathematical Model ◽  
Regenerative Cycle

A consideration subject in article is the mathematical model of pressure recovery factor of microgas turbine plants (MGTP) regenerators which considers dependence of hydraulic resistance of the heat–exchanger on the its surface area. Optimization of a regenerative cycle of MGTP and a cycle with regeneration and the turbocompressor utilizer for the purpose of further increase in their profitability is performed. It is established that use of the offered model of pressure recovery factor on the air and gas side allows to find degree of regeneration heattechnical optimum. This model can be used at simplified and predesign of MGTP.

Experimental and numerical studies of the effect of area ratio and driving pressure on the performance of water and slurry jet pumps

2011 ◽  
Vol 226 (9) ◽  
pp. 2250-2266 ◽  
Author(s):  
Tarek Meakhail ◽  
Ibrahim Teaima
Keyword(s):  
Area Ratio ◽  
Driving Pressure ◽  
Operating Conditions ◽  
Jet Pump ◽  
Numerical Studies ◽  
Pumping Stations ◽  
Mixing Chamber ◽  
Jet Pumps ◽  
Different Diameters ◽  
Experimental Rig

The slurry jet pump with scouring nozzle system can be used in dredging of sites, which are difficult to access or need handling of equipments that are used for the intake of pumping stations under bridges and concrete water channels. This system is suitable for sand, silt, sludge, mud, and other organic materials. The aim of this study is to investigate the performance of water and slurry jet pumps. The effects of the pump-operating conditions and geometries on its performance were investigated. The experimental rig was constructed in such a way that the driving nozzle diameter can be changed. In this study, three different diameters of driving nozzles, 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 R = 0.155, 0.25, and 0.4). Also, the effect of driving pressure has been investigated. The results show that increasing the area ratio decreases the maximum mass flow ratio. The results of computational fluid dynamics were found to agree well with actual values obtained from the experimental water and slurry jet pump.

An Investigation of Ejector Design by Analysis and Experiment

1950 ◽  
Vol 17 (3) ◽  
pp. 299-309
Author(s):  
J. H. Keenan ◽  
E. P. Neumann ◽  
F. Lustwerk
Keyword(s):  
Experimental Data ◽  
Constant Pressure ◽  
Jet Pump ◽  
Pump Design ◽  
One Dimensional ◽  
Analytical Results ◽  
Constant Area ◽  
Jet Pumps ◽  
Good Agreement

Abstract A one-dimensional method of analysis of jet pumps or ejectors is presented. The analysis considers mixing of the primary and secondary streams at constant pressure, and mixing of the streams at constant area. For the analytical conditions considered, better performance can be obtained when constant-pressure mixing is employed. A comparison between experimental and analytical results shows good agreement over a broad range of variables. Some experimental data on the length of tube required for mixing of the two streams are presented. A method for jet-pump design is given.

Numerical Investigation of Geometric Factors for Design of High Performance Air-Jet Pumps Using in Vehicle-Mounted Vacuum Toilet

2011 ◽  
Vol 268-270 ◽  
pp. 46-50
Author(s):  
Fei Gao ◽  
Jing Xuan Zhou ◽  
Min Li
Keyword(s):  
High Performance ◽  
Operating Conditions ◽  
Cfd Model ◽  
Jet Pump ◽  
Air Jet ◽  
Geometric Factors ◽  
Constant Area ◽  
Jet Pumps ◽  
Computational Fluid Dynamics Cfd ◽  
Area Section

Air-jet pump as the pneumatic source of a vehicle-mounted vacuum toilet provides the vacuum to pump the fecal sewage out of toilet bowl via the compressed air passing through the pump under certain pressure. In this study, Computational Fluid Dynamics (CFD) technique is employed to investigate the effects of three important air-jet pump geometry parameters: the primary Nozzle Exit Position (NXP), the constant-area section length (L1) and the diffuser diverging angle (θ), on its performance. A CFD model is firstly established according to 1D analytical method, and then used to create 135 different air-jet pump geometries and tested under different operating conditions. The significance of this study is that these findings can be used to guide the adjustment of NXP, L1 and θ to obtain the best air-jet pump performance when the operating conditions are different.

scholarly journals Обґрунтування моделі турбулентної в’язкості для дослідження характеристик співвісного гвинтовентилятора і вхідного пристрою ГТД

2021 ◽  
pp. 35-39
Author(s):  
Олег Володимирович Жорник ◽  
Ігор Федорович Кравченко ◽  
Михайло Михайлович Мітрахович ◽  
Олеся Валеріїна Денисюк
Keyword(s):  
Mathematical Modeling ◽  
Total Pressure ◽  
Turbulent Viscosity ◽  
Flight Test ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Recovery Coefficient ◽  
Transition Analysis ◽  
Total Pressure Recovery ◽  
Pressure Recovery Factor

The issues of substantiation of the most rational, based on adequacy, model of turbulent viscosity for mathematical modeling of the flow near the propfan and in the inlet of the turbine-propeller engine are considered. It was found that at present there is no universal turbulence model for determining the parameters of the boundary layer, energy loss in the flow, and laminar-turbulent transition. Analysis of the results of previous studies showed that there is a need to select and justify a turbulent viscosity model for each type of research object. The task of modeling the flow near the propfan and in the inlet device of the power plant was performed using the ANSYS CFX software product, which allows using various standard mathematical models and tools for modeling turbulent flow. The object of research is an annular axial inlet device, in front of which there is a coaxial propfan with two rows of propellers: the first row has eight blades, the second - six. 7 types of models of turbulent viscosity, which most fully describe the phenomena in the flow around the propfan and the inlet device, have been investigated: k-ωmodel; SSТ (shear stress transport) SST Transitional №1 Fully turbulence; SST Transitional №2 Specified Intermittency; SST Transitional №3 Gamma model; SST Transitional №4 Gamma theta model; SST Transitional №5 Intermittency. The results of mathematical modeling of the flow near the propfan and in the inlet device at the corresponding operating mode of the turbopropfan engine using the selected models of turbulent viscosity, the total pressure value in front of and behind the inlet device was obtained to determine the total pressure recovery coefficient in it and the value of the propfan thrust. The value of the recovery factor of the total pressure in the inlet device and the propfan thrust are compared with the flight test data of the prototype. An analysis of the comparison of the values of the total pressure recovery factor in the inlet device and the propfan thrust showed that the use of the SST Transitional №4 Gamma theta model allows obtaining the value of the total pressure recovery factor in the inlet device and the propfan thrust that is closest to the flight test results.

Growth of the total pressure recovery factor in a flow behind a shock wave emerging from a channel with concave corners in cross section

2003 ◽  
Vol 29 (5) ◽  
pp. 385-387 ◽  
Author(s):  
T. V. Bazhenova ◽  
V. V. Golub ◽  
A. L. Kotel’nikov ◽  
A. S. Chizhikov ◽  
M. V. Bragin
Keyword(s):  
Shock Wave ◽  
Cross Section ◽  
Total Pressure ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Total Pressure Recovery ◽  
Pressure Recovery Factor

Improving the Efficiency of a Hydro-Turbine System by Vortex Generators

2011 ◽  
Vol 354-355 ◽  
pp. 636-641 ◽  
Author(s):  
Hua Chen Pan ◽  
Shu Li Hong
Keyword(s):  
Working Conditions ◽  
Draft Tube ◽  
Vortex Generators ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Hydro Turbine ◽  
Turbine Performance ◽  
Pressure Recovery Factor ◽  
Inside Wall

This paper studies the effect of vortex generators on hydro-turbine working performances. The study was carried out on a hydro-turbine system provided by Waterpumps Oy, Finland. First, the performance of the hydro-turbine system was analyzed with a CFD solver under different working conditions. Then, the hydro-turbine performance was examined with several vortex generators installed uniformly on the inside wall of the draft tube near its inlet. The turbine system’s efficiencies were compared for cases with and without vortex generators. Results show that turbine performs better when there are vortex generators installed in the draft tube of which the pressure recovery factor is much higher.

scholarly journals Удосконалення характеристик кільцевого вхідного пристрою авіаційної силової установки з гвинтовентилятором

2021 ◽  
pp. 11-18
Author(s):  
Олег Володимирович Жорник ◽  
Ігор Федорович Кравченко ◽  
Михайло Михайлович Мітрахович
Keyword(s):  
Total Pressure ◽  
Influential Factor ◽  
Recovery Factor ◽  
Pressure Recovery ◽  
Input Device ◽  
Navier Stokes Equation ◽  
Element Analysis ◽  
Turboprop Engine ◽  
Pressure Recovery Factor ◽  
Full Pressure

The article considers the method of improving the characteristics of the ring inlet device, taking into account the influence of the propeller of an aircraft power plant with a turboprop engine. It is shown that increasing the total pressure loss in the inlet device by 5% increases, approximately, the specific fuel consumption by 3% and reduces engine thrust by 6%, and uneven flow at the inlet to the engine is the cause of unstable compressor of the turboprop engine. It is proposed to improve the characteristics of the input device by modifying the shape of its shell and channel. Evaluation of the influence of the shape of the shell and the channel of the annular axial VP on its main aerodynamic characteristics, taking into account the non-uniformity of the flow on the fan in the calculated mode of operation of the SU is carried out by calculating the full pressure recovery factor. The object of the study is an annular axial input device in front of which is a coaxial fan turboprop fan. The process of modeling the influence of the shape of the shell and the channel on the recovery factor of total pressure, circular and radial non-uniformity of the flow through the input device is implemented in the software system of finite element analysis ANSYS CFX. Geometric models of coaxial screw fan, fairing and inlet device are built in ANSYS SpaceClaim and transferred using the built-in import function in ANSYS Workbench. Block-structured grid models of air propellers of the first and second rows of the fan in the amount of 1.9 million, fairing and inlet device, in the amount of 3.9 million, are built in the ANSYS TurboGrid environment. The standard Stern (Shear Stress Transport) Gamma Theta Transition was used to close the Navier-Stokes equation system. Based on the results of mathematical modeling of flow in coaxial fans and subsonic ring inlet device on the maximum cruising mode of the turboprop engine, the full pressure recovery factor is calculated and it is established that the most influential factor that increases its full pressure recovery factor.

Liquid Jet Pumps for Two-Phase Flows

1995 ◽  
Vol 117 (2) ◽  
pp. 309-316 ◽  
Author(s):  
R. G. Cunningham
Keyword(s):  
Secondary Flow ◽  
Gas Flow ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Liquid Jet ◽  
Dimensionless Number ◽  
Jet Pump ◽  
Two Phase ◽  
Performance Curves ◽  
Jet Pumps

Isothermal compression of a bubbly secondary fluid in a mixing-throat and diffuser is described by a one-dimensional flow model of a liquid-jet pump. Friction-loss coefficients used in the four equations may be determined experimentally, or taken from the literature. The model reduces to the liquid-jet gas compressor case if the secondary liquid is zero. Conversely, a zero secondary-gas flow reduces the liquid-jet gas and liquid (LJGL) model to that of the familiar liquid-jet liquid pump. A “jet loss” occurs in liquid-jet pumps if the nozzle tip is withdrawn from the entrance plane of the throat, and jet loss is included in the efficiency equations. Comparisons are made with published test data for liquid-jet liquid pumps and for liquid-jet gas compressors. The LJGL model is used to explore jet pump responses to two-phase secondary flows, nozzle-to-throat area ratio, and primary-jet velocity. The results are shown in terms of performance curves versus flow ratios. Predicted peak efficiencies are approximately 50 percent. Under severe operating conditions, LJGL pump performance curves exhibit maximum-flow ratios or cut-offs. Cut-off occurs when two-phase secondary-flow streams attain sonic values at the entry of the mixing throat. A dimensionless number correlates flow-ratio cut-offs with pump geometry and operating conditions. Throat-entry choking of the secondary flow can be predicted, hence avoided, in designing jet pumps to handle two-phase fluids.

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