Induced Flow Reciprocating Pump Theory Supported by New Performance Data

1972 ◽  
Vol 94 (4) ◽  
pp. 706-714 ◽  
Author(s):  
J. D. Burton ◽  
J. Lobo-Guerrero U.
Keyword(s):  
High Speed ◽  
Performance Data ◽  
Experimental Measurements ◽  
Long Time ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Reciprocating Pump

Reciprocating pumps have been employed in conjunction with air vessels and fluid accumulators for a long time in order to reduce maximum cylinder pressures and energy wastage in friction. More recently, diaphragm pumps, run at high speed, have been built utilizing a hydraulic accumulator or capacitance in conjunction with a hydraulic inductance, in order to greatly increase the flow output. Volumetric efficiencies of over 250 percent have been obtained. The present paper describes briefly this induced flow principle and then compares theoretical solutions with experimental measurements taken in the first commercially available pump of this type.

High Speed Induced Flow Reciprocating Pumps

1972 ◽  
Vol 186 (1) ◽  
pp. 785-791
Author(s):  
R. L. Creedon ◽  
J. Lobo-Guerrero ◽  
P. R. Selwood ◽  
J. D. Burton
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Performance Data ◽  
Analogue Computer ◽  
Pump Frequency ◽  
Discharge Line ◽  
New Type ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Work Done

Reciprocating pumps have been used for many years in conjunction with an air vessel or hydraulic accumulator placed between pump and discharge line, in order to control maximum cylinder pressures and to reduce the work done in overcoming friction. The air vessel and the discharge line are, in fact, capacitive and inductive components which together have some natural frequency generally different from the pump frequency. In this paper, it is shown that by matching the natural frequency of the discharge impedance to the pump frequency it is possible to obtain volumetric efficiencies of 200 per cent or more. This ‘induced flow principle’ was incorporated in a small high speed pump developed specifically to overcome the relative bulk and cost of conventional diaphragm pumps. Performance data for the new type of pump are compared with theoretical analogue computer solutions, and it appears that the induced flow principle may have a wider range of application than originally anticipated.

scholarly journals Broadband Power Line Communication for Integration of Energy Sensors within a Smart City Ecosystem

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3402
Author(s):  
Jan Slacik ◽  
Petr Mlynek ◽  
Martin Rusz ◽  
Petr Musil ◽  
Lukas Benesl ◽  
...  
Keyword(s):  
Smart Grids ◽  
High Speed ◽  
Power Line ◽  
Experimental Simulation ◽  
Power Line Communication ◽  
Experimental Measurements ◽  
Simulation Tool ◽  
Smart Metering ◽  
Complex Simulation ◽  
Simulation Results

The popularity of the Power Line Communication (PLC) system has decreased due to significant deficiencies in the technology itself, even though new wire installation is not required. In particular, regarding the request for high-speed throughput to fulfill smart-grid requirements, Broadband Power Line (BPLC) can be considered. This paper approaches PLC technology as an object of simulation experimentation in the Broadband Power Line Communication (BPLC) area. Several experimental measurements in a real environment are also given. This paper demonstrates these experimental simulation results as potential mechanisms for creating a complex simulation tool for various PLC technologies focusing on communication with end devices such as sensors and meters. The aim is to demonstrate the potential and limits of BPLC technology for implementation in Smart Grids or Smart Metering applications.

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

scholarly journals High speed internet development in Africa using 4G-LTE technology-a review

2019 ◽  
Vol 8 (2) ◽  
pp. 577-585
Author(s):  
Mohamed Njikam ◽  
Nanna S. ◽  
Shahrin S. ◽  
Mohd Fairuz Iskandar Othman
Keyword(s):  
High Speed ◽  
Telecommunication Networks ◽  
African Continent ◽  
African Countries ◽  
Lte Networks ◽  
Telecommunication Infrastructure ◽  
Long Time ◽  
Populated Region ◽  
4G Lte ◽  
Internet Development

The African continent is ranked second most populated region and has a huge amount of natural resources to be locally transformed or outsourced overseas. The traditional telecommunications system has helped connect people and enabled them to manage their businesses and trading in Africa for a long-time; many African countries have embarked early in changing their network and technology systems during the first years of the information age. Over a few decades ago, the introduction of new telecommunication methods and techniques have influenced much of African countries’ growth via different perspectives. The situation has triggered an enormous interest in people. They analyzed the factors supporting such changes, which in the case of this paper is all about the advent and adoption of LTE/4G-LTE technologies including its service commercialization in Africa. This review article attempts to provide an overview of 4G-LTE networks technologies and the internet; it includes the current evolution of telecommunication networks within and even beyond the African continent, assisted by the 4G-LTE expansion. An extended view is provided throughout this article’s development with respect to what could be expected (or is missing) for the sake of this continent’s telecommunication infrastructure enhancement and a better QoS to Africa’s dwellers.

An Analysis of Heave Added Mass and Damping of a Surface-Effect Ship

1981 ◽  
Vol 25 (01) ◽  
pp. 44-61
Author(s):  
C. H. Kim ◽  
S. Tsakonas
Keyword(s):  
Free Surface ◽  
High Speed ◽  
Surface Effect ◽  
Practical Method ◽  
Added Mass ◽  
Damping Coefficients ◽  
Calm Water ◽  
Surface Effect Ship ◽  
Long Time ◽  
Computational Procedures

The analysis presents a practical method for evaluating the added-mass and damping coefficients of a heaving surface-effect ship in uniform translation. The theoretical added-mass and damping coefficients and the heave response show fair agreement with the corresponding experimental values. Comparisons of the coupled aero-hydrodynamic and uncoupled analytical results with the experimental data prove that the uncoupled theory, dominant for a long time, that neglects the free-surface effects is an oversimplified procedure. The analysis also provides means of estimating the wave elevation of the free surface, the escape area at the stern and the volume which are induced by a heaving surface-effect ship in uniform translation in otherwise calm water. Computational procedures have been programmed in the FORTRAN IV language and adapted to the PDP-10 high-speed digital computer.

scholarly journals Interplanetary Response to Solar Long Time-Scale Phenomena

1980 ◽  
Vol 91 ◽  
pp. 105-125
Author(s):  
C. D'Uston ◽  
J. M. Bosqued
Keyword(s):  
Solar Wind ◽  
Time Scale ◽  
High Speed ◽  
Coronal Holes ◽  
Observational Evidence ◽  
Solar Wind Flow ◽  
Speed Solar Wind ◽  
Long Time ◽  
Outer Corona ◽  
High Speed Solar Wind

In this paper, we briefly review the experimental knowledge gained in the recent years on the interplanetary response to solar long-time scale phenomena such as the coronal magnetic structure and its evolution. Observational evidence that solar wind flow in the outer corona comes from the unipolar diverging magnetic regions of the photosphere is discussed along with relations to coronal holes. High-speed solar wind streams observed within the boundary of interplanetary magnetic sectors are associated with these structures. Their boundaries appear as very narrow velocity shears.

scholarly journals White Dwarf Pulsations

1980 ◽  
Vol 5 ◽  
pp. 469-472
Author(s):  
W. Dziembowski
Keyword(s):  
Effective Temperature ◽  
High Speed ◽  
White Dwarfs ◽  
Binary Systems ◽  
Early Suggestion ◽  
Nonradial Oscillation ◽  
High Speed Photometry ◽  
Long Time ◽  
Nuclear Burning ◽  
Radial Pulsations

It has been known for a long time that white dwarfs are pulsationally unstable if nuclear burning takes place in their envelopes. Perturbation of energy generation rate promotes pulsational instability and this effect is frequently referred to as ε-mechanism. In recent years, with the advent of high-speed photometry, many rapidly varying white dwarfs have been discovered. However, periods of variability were found to be significantly longer than the periods of radial pulsations which were the only type of oscillations considered before the discovery. Furthermore, the case of ε-mechanism as being responsible for the observed variability has never been made strong for any of the observed objects.Variable white dwarfs are found among: Io single DA-type objects in the effective temperature range 10000-15000K; 2o members of close, usually but not always, cataclysmic binary systems. Although, following an early suggestion by Warner and Robinson (1972), the excitation of nonradial oscillation is postulated in both cases, the two types represent very different physical situations and they will be discussed here separately.

scholarly journals Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High-Speed Diffuser Flow

2001 ◽  
Vol 7 (6) ◽  
pp. 375-385 ◽  
Author(s):  
R. C. Hendricks ◽  
D. T. Shouse ◽  
W. M. Roquemore ◽  
D. L. Burrus ◽  
B. S. Duncan ◽  
...  
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Fuel Injection ◽  
Computational Study ◽  
Combustion Efficiency ◽  
Flame Stabilization ◽  
Performance Data ◽  
Pollutant Emissions ◽  
Choked Flow ◽  
Trapped Vortex

The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

Improvement of Firing Frequency Limits by Investigation of Ejection Failure Modes in Thermal Inkjet Print Heads

Volume 4 ◽  
2004 ◽  
Author(s):  
Min Soo Kim ◽  
Dong Kee Sohn ◽  
Seung Joo Shin ◽  
Keon Kuk ◽  
Yong Soo Oh
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Flow Resistance ◽  
Failure Modes ◽  
Firing Frequency ◽  
Resistance Ratio ◽  
Frequency Limit ◽  
Optimal Flow ◽  
Speed Performance ◽  
Induced Flow

Ejection failure modes determining the firing frequency limit in thermal inkjet heads were investigated from performance experiments and numerical simulations. Dominant failure modes were affected by the flow resistance ratio in the ink flow passages. Optimal flow resistance ratios were obtained experimentally to provide maximum frequency limits for both mono and color inkjet heads. Numerical simulations were performed on the meniscus oscillation, the ejection behavior in consecutive firing, and the cross-talk induced flow. Numerical results supported the importance of flow resistance ratio in maximizing firing frequency limit in both unit nozzle and multi-nozzle firing. Our investigation will help to develop the inkjet print heads of more reliable high-speed performance.

The Effect of Oil Droplet on the Lubrication Performance

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Shengguang Zhang ◽  
Wenzhong Wang ◽  
Xinming Li ◽  
Feng Guo
Keyword(s):  
High Speed ◽  
Contact Region ◽  
Oil Droplet ◽  
Large Size ◽  
Lubrication Performance ◽  
Air Lubrication ◽  
Long Time ◽  
Base Radius ◽  
The One ◽  
Starvation Conditions

Oil–air lubrication is widely used in the high-speed rotary machines; the oil is usually in the form of discrete droplets. The lubrication behavior of the oil droplet is rarely investigated. This paper investigates the effect of the oil droplet on lubrication performance based on the developed transient lubrication model with consideration of starvation conditions. The oil droplet is modeled as spherical segment with different heights, base radius, and positions, which will change the inlet oil supply conditions. The results show that the oil droplet with large size can generate thick oil film which is close to the one in fully flooded condition and can remain long time; the position of the oil droplet entering the contact region also has significant effect on the lubrication performance.

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