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.

Design and Application of Low Flow Steam Siphon Jet Pumps

2016 ◽  
Author(s):  
Robert A. Leishear ◽  
William M. Bennett ◽  
Jackie Cooper
Keyword(s):  
Experimental Data ◽  
Specific Gravity ◽  
Closed Form ◽  
Steam Pressure ◽  
Control Flow ◽  
Low Flow ◽  
Jet Pump ◽  
Pump Design ◽  
Flow Rates ◽  
Jet Pumps

Low flow steam siphon jet pumps are referred to as rate jets, since these pumps have the ability to control flow rates by varying the steam pressure applied to the jet. The jet pump design consists of several components. Steam inlet piping is connected to a steam nozzle that directs steam into the jet body to provide energy to lift a liquid, or feed. Feed is lifted up through the suction lift piping, where the condensing steam forces the liquid into a diffuser and out of the jet discharge piping. Closed form equations cannot model these jets, and commercial computer models to describe jet performance are still in a state of development. In general, experimental data is required to determine the performance characteristics of this type of jet design. Numerous tests were performed on different jet designs to evaluate the effects of motive steam pressures, suction lift, discharge head, jet dimensions, and the specific gravity of the fluid that is lifted and pumped by the jet. Additionally, the system installation significantly affects the performance of siphon jets, and one such installation was studied.

A One-Dimensional Numerical Model for the Momentum Exchange in Regenerative Pumps

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Francis J. Quail ◽  
Matthew Stickland ◽  
Armin Baumgartner
Keyword(s):  
Experimental Data ◽  
Low Flow ◽  
Correction Factors ◽  
Momentum Exchange ◽  
Pump Design ◽  
Pump Performance ◽  
One Dimensional ◽  
Geometry Model ◽  
Wide Range ◽  
Dimensional Models

The regenerative pump is a rotor-dynamic turbomachine capable of developing high heads at low flow rates and low specific speeds. In spite of their low efficiency, usually less than 50%, they have found a wide range of applications as compact single-stage pumps with other beneficial features. The potential of a modified regenerative pump design is presented for the consideration of the performance improvements. In this paper the fluid dynamic behavior of the novel design was predicted using a one-dimensional model developed by the authors. Unlike most one-dimensional models previously published for regenerative pumps, the momentum exchange is numerically computed. Previous one-dimensional models relied on experimental data and correction factors; the model presented in this paper demonstrates an accurate prediction of the pump performance characteristics without the need for correction with experimental data. The validity of this approach is highlighted by the comparison of computed and measured results for two different regenerative pump standards. The pump performance is numerically assessed without the need of correction factors or other experimental data. This paper presents an approach for regenerative pumps using a physically valid geometry model and by resolving the circulatory velocity in the peripheral direction.

Theoretical Modeling of Central Air-Jet Pump Performance for Pneumatic Transportation of Bulk Solids

1999 ◽  
Vol 121 (2) ◽  
pp. 365-372 ◽  
Author(s):  
D. Wang ◽  
P. W. Wypych
Keyword(s):  
Analytical Procedure ◽  
Area Ratio ◽  
Jet Pump ◽  
Pump Performance ◽  
Bulk Solids ◽  
Air Jet ◽  
Performance Predictions ◽  
Jet Pumps ◽  
Pneumatic Transportation ◽  
Good Agreement

A mathematical model to predict the air-solids performance of central air-jet pumps has been developed based on the fundamentals of fluid and particle mechanics. The influence of throat entry configuration on performance has been incorporated into the analytical model by introducing a throat entry function and suction area ratio. Nondimensional parameters to represent air-solids jet pump performance has been defined and used in the analytical procedure. The performance predictions obtained by this model show good agreement with experimental results.

scholarly journals Time-Fractional Model of Chloride Diffusion in Concrete: Analysis Using Meshless Method

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ling Yao ◽  
Lixia Ren ◽  
Guoli Gong
Keyword(s):  
Experimental Data ◽  
Meshless Method ◽  
Model Simulation ◽  
Order Equation ◽  
Chloride Diffusion ◽  
Fractional Model ◽  
One Dimensional ◽  
Element Free Galerkin ◽  
Element Free ◽  
Good Agreement

Chloride diffusion is the major factor that affects the life of concrete structures. The time-fractional order equation can be used to describe anomalous diffusion in reinforced concrete. In this work, a time-fractional model of chloride diffusion is solved via the meshless method. The Element-Free Galerkin (EFG) meshless method does not require meshing. One-dimensional and two-dimensional numerical examples are presented. Numerical results are in good agreement with theoretical solutions. The initiation time of corrosion is predicted in the presented model. Simulation results are compared with experimental data. The good agreement between EFG and experimental data indicates that time-fractional chloride diffusion in concrete can be modeled effectively by using the EFG method. This method is beneficial for further research on anomalous chloride diffusion in concrete.

Precursor shock waves at a slow—fast gas interface

1976 ◽  
Vol 76 (1) ◽  
pp. 157-176 ◽  
Author(s):  
A. M. Abd–El–Fattah ◽  
L. F. Henderson ◽  
A. Lozzi
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Shock Wave ◽  
Shock Waves ◽  
Plane Shock ◽  
One Dimensional ◽  
Irregular Wave ◽  
Irregular Systems ◽  
Theory And Experiment ◽  
Good Agreement

This paper presents experimental data obtained for the refraction of a plane shock wave at a carbon dioxide–helium interface. The gases were separated initially by a delicate polymer membrane. Both regular and irregular wave systems were studied, and a feature of the latter system was the appearance of bound and free precursor shocks. Agreement between theory and experiment is good for regular systems, but for irregular ones it is sometimes necessary to take into account the effect of the membrane inertia to obtain good agreement. The basis for the analysis of irregular systems is one-dimensional piston theory and Snell's law.

Unsteady One-Dimensional Compressible Frictional Flow with Heat Transfer

1972 ◽  
Vol 14 (6) ◽  
pp. 365-369 ◽  
Author(s):  
R. I. Issa ◽  
D. B. Spalding
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Unsteady Flow ◽  
Hybrid Method ◽  
Numerical Procedure ◽  
Rectangular Grid ◽  
Paper Briefly ◽  
One Dimensional ◽  
Flow Problems ◽  
Good Agreement

The paper briefly describes a numerical procedure for solving problems of one-dimensional, unsteady, compressible, frictional flows with heat transfer. The procedure is based on the Hartree ‘hybrid’ method which combines the use of a rectangular grid with the use of characteristics. The main features of the procedure are its applicability and ease of adaptability to complex unsteady-flow problems. Another feature is the simplicity of its programming for a computer. Computations for flows in shock tubes are presented; they are in good agreement with previously published experimental data.

Measuring the relative humidity of humid air using a hair hygrometer

2003 ◽  
Vol 217 (5) ◽  
pp. 379-385
Author(s):  
M A Mehrabian ◽  
M Hashemian
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Relative Humidity ◽  
Hair Sample ◽  
Linear Expansion ◽  
Dimensional Change ◽  
Humid Air ◽  
One Dimensional ◽  
Psychrometric Chart ◽  
Good Agreement

An instrument has been designed and constructed to allow direct measurement of the relative humidity of humid air. The objective of the study is to use the effect of humidity on the linear expansion of a piece of hair that is pulled with a spring or a small weight while exposed to the humid air. This can result in producing such an instrument if the hair sample is specific. For the hair used in this work, relative humidities ranging from 0 to 100 per cent result in a one-dimensional change of about 0.02m/m. As the humidity of the air is decreased or increased, the hair is shortened or lengthened and turns the pointer connected to its end. The pointer detects the relative humidity of humid air on a calibrated plate. A series of experimental data are extracted in different environments using this instrument. The data are in good agreement with the results obtained from the psychrometric chart and mass transfer calculations.

NANOMATERIALS UNDER HIGH TEMPERATURE AND HIGH PRESSURE

2010 ◽  
Vol 24 (26) ◽  
pp. 2647-2657 ◽  
Author(s):  
R. KUMAR ◽  
UMA D. SHARMA ◽  
MUNISH KUMAR
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Thermal Expansion ◽  
High Temperature ◽  
Constant Pressure ◽  
Effect Of Temperature ◽  
Effect Of Pressure ◽  
Approaches To Study ◽  
Theory And Experiment ◽  
Good Agreement

Two different approaches to study thermal expansion and compression of nanosystems are unified, which have been treated quite independently by earlier workers. We provide the simple theoretical analysis, which demonstrates that these two approaches may be unified into a single theory, viz. one can be derived from other. It is concluded that there is a single theory in the place of two different approaches. To show the real connection with the nanomaterials, we study the effect of temperature (at constant pressure), the effect of pressure (at constant temperature) as well as the combined effect of pressure and temperature. We have considered different nanomaterials viz. carbon nanotube, AlN , Ni , 80 Ni –20 Fe , Fe – Cu , MgO , CeO 2, CuO and TiO 2. The results obtained are compared with the available experimental data. A good agreement between theory and experiment demonstrates the validity of the present approach.

Self-Entrainment Characteristics and Performance of a Compact Air Ejector

2008 ◽  
Author(s):  
Kartik V. Bulusu ◽  
Charles A. Garris
Keyword(s):  
Performance Analysis ◽  
Computer Program ◽  
Constant Pressure ◽  
Automotive Applications ◽  
Refrigeration System ◽  
One Dimensional ◽  
Constant Area ◽  
Dimensional Parameters ◽  
And Performance ◽  
Air Ejector

A one dimensional method of analysis and experimentally determined entrainment and compression ratios are presented with considerations made for constant pressure and constant area mixing. A set of three nozzles, one converging and two converging diverging, were used to study the isentropic characteristics of the ejector performance. Ejector efficiencies are calculated using the turbomachinery analogue of compressors where adiabatic and complete mixing of primary and secondary fluids is assumed before discharge. Efficiencies are characterized against non-dimensional parameters chosen in context. A generalized algorithm and corresponding MATLAB™ based computer program was developed for performance analysis. While exploring the possibility of a refrigeration system for automotive applications where the size of the ejector could play an important role, a compact experimental ejector was designed and tested.

Experiment and Analysis of Instability of Tube Rows Subject to Liquid Crossflow

1982 ◽  
Vol 49 (4) ◽  
pp. 704-709 ◽  
Author(s):  
S. S. Chen ◽  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Data ◽  
Analytical Study ◽  
Displacement Mechanism ◽  
Analytical Results ◽  
Damping Parameter ◽  
Good Agreement

A tube array subjected to crossflow may become unstable by either one or both of the two basic mechanisms: velocity mechanism and displacement mechanism. An experimental and analytical study of tube rows in liquid crossflow is performed to verify the existence and transition between the two mechanisms at the intermediate values of mass-damping parameter. Experimental data and analytical results are found to be in good agreement.

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