Quantifying the Pumping Energy Loss Associated with Different Types of Leak in a Piping System

2017 ◽  
pp. 107-118 ◽  
Author(s):  
L. Latchoomun ◽  
D. Mawooa ◽  
Robert T. F. Ah King ◽  
K. Busawon ◽  
R. Binns
Keyword(s):  
Energy Loss ◽  
Piping System ◽  
Different Types

Fluid turbulence simulations of divertor heat load for ITER hybrid scenario using BOUT++

2021 ◽  
Author(s):  
Xueyun Wang ◽  
Xueqiao Xu ◽  
Philip B Snyder ◽  
Zeyu Li
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Energy Loss ◽  
Heat Load ◽  
Type I ◽  
Fluid Turbulence ◽  
Drift Model ◽  
Steady State Operation ◽  
Different Types ◽  
The One

Abstract The BOUT++ six-field turbulence code is used to simulate the ITER 11.5MA hybrid scenario and a brief comparison is made among ITER baseline, hybrid and steady-state operation (SSO) scenarios. Peeling-ballooning instabilities with different toroidal mode numbers dominate in different scenarios and consequently yield different types of ELMs. The energy loss fractions (ΔWped/Wped) caused by unmitigated ELMs in the baseline and hybrid scenarios are large (~2%) while the one in the SSO scenario is dramatically smaller (~1%), which are consistent with the features of type-I ELMs and grassy ELMs respectively. The intra ELM divertor heat flux width in the three scenarios given by the simulations is larger than the estimations for inter ELM phase based on Goldston’s heuristic drift model. The toroidal gap edge melting limit of tungsten monoblocks of divertor targets imposes constraints on ELM energy loss, giving that the ELM energy loss fraction should be smaller than 0.4%, 1.0%, and 1.2% for ITER baseline, hybrid and SSO scenarios, correspondingly. The simulation shows that only the SSO scenario with grassy ELMs may satisfy the constraint.

Minimum Pumping Energy of Tree-Shaped Water Supply Networks for Probabilistic Demands in Built Environment

2012 ◽  
Author(s):  
L. T. Wong ◽  
K. W. Mui ◽  
C. T. Cheung
Keyword(s):  
Built Environment ◽  
Energy Loss ◽  
Water Supply ◽  
Water Distribution ◽  
Probabilistic Approach ◽  
Piping System ◽  
Tree Shape ◽  
Reduction Potentials ◽  
Sustainable Water Supply ◽  
Friction Energy

Minimization of pumping energy is a major concern for designing sustainable water supply in buildings. Modular designs of tree-shaped water supply piping system, such as 2 by N array include water cisterns of water closet in public toilets, washbasin taps in schools are commonly found in building complexes. Potable water demands in water systems serving built environment are unsteady, random and intermittent. However, the existing statistical Hunter-based probabilistic approaches to pipe sizing, however, do not consider the minimization of pumping energy for water distribution through proper selection of pipe radii. This paper demonstrates a pipe sizing method with probabilistic demands for optimizing pipe friction energy loss constrained by the fixed pipeline volume. A mathematical model for pumping energy optimization in infinite tree-shape water supply piping networks for probabilistic demands is proposed. Compared with the Hunter’s based probabilistic approach in sizing an 8-section tree-shape water supply network for demand of probabilities 0.1 and 0.2, the proposed method offers reduction potentials of pipe friction energy loss of 12% and 43% respectively. With piping systems of pipe radius ratios, the optimal tree-shape networks are also determined.

Electron Energy Loss Spectroscopy at 5Å Spatial Resolution

1985 ◽  
Vol 43 ◽  
pp. 396-397
Author(s):  
M. Isaacson ◽  
M. Scheinfein
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Spatial Resolution ◽  
Electron Energy Loss Spectroscopy ◽  
Incident Beam ◽  
Beam Current ◽  
Different Types ◽  
Half Angle ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

One of the ultimate goals of electron energy loss spectroscopy within the electron microscope is to be able to obtain the electronic structure of interfaces at near atomic resolution. Though this goal has not yet been achieved, there has been considerable effort devoted to elemental composition at high spatial resolution using ELS (eg. References 1-3). In this paper we wish to present initial measurements made across different types of interfaces that show core and valence shell electron energy loss spectra changing within an 8Å spatial scale across the interface.All the measurements have been performed using a modified dedicated STEM (VG Scientific HB-5) equipped with beam blanking facilities, digital control and a wide-gap aberration connected energy loss spectrometer. The details of this instrument have been described elsewhere (4). The main point to be noted is that the incident illumination half angle was 7.5mrad for these experiments and the full width at half maximum of the probe was 4.6Å (measured). With these optical conditions, 90% of all the incident beam current is contained within a diameter of 9.0Å (5). For beam sensitive materials, the recording dose was kept to less than 1/3 the dose for observable sample degradation.

scholarly journals Determination of Mechanical Energy Loss in Steady Flow by Means of Dissipation Power

2017 ◽  
Vol 64 (2) ◽  
pp. 73-85 ◽  
Author(s):  
Wojciech Artichowicz ◽  
Jerzy M. Sawicki
Keyword(s):  
Energy Loss ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Mechanical Energy ◽  
Turbulent Viscosity ◽  
Viscosity Coefficient ◽  
Mechanical Energy Loss ◽  
Different Types ◽  
Loss Determination

Abstract When systems of simple geometry like pipes or regular channels are considered, the mechanical energy loss of the fluid flow can be expressed by local and longitudinal empirical energy loss coefficients. However, in the case of large spatially distributed objects, there are no simple approaches to this task. In practice, general recommendations addressing different types of objects are used, but they usually provide very coarse estimates of energy loss. In this work, a new methodology for determination of mechanical energy loss in steady flowis proposed. This methodology is based on the observation that the magnitude of the power of energy dissipation in turbulent flow can be determined using the averaged flow velocity and turbulent viscosity coefficient. To highlight this possibility, an analysis of the magnitudes of the power of the main and fluctuating components of turbulent flow is presented. The correctness of the method is verified using an example of laminar and turbulent flows in a circular pipe. The results obtained show clearly that the proposed methodology can be used for mechanical energy loss determination in flow objects. This methodology can be used as a basis for mechanical energy loss determination in different types of flow objects.

scholarly journals Comprehensive Methodology to Evaluate Parasitic Energy Consumption for Different Types of Dual-Axis Sun Tracking Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ming-Hui Tan ◽  
Tze-Koon Wang ◽  
Chee-Woon Wong ◽  
Kok-Keong Chong ◽  
Boon-Han Lim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Loss ◽  
Tracking System ◽  
Electrical Energy ◽  
Photovoltaic System ◽  
The Sun ◽  
Tracking Systems ◽  
Optical Efficiency ◽  
Different Types ◽  
Energy Consumptions

A dual-axis sun tracking system is an essential strategy to maximize the optical efficiency of harnessing solar energy. However, there is no significant study yet to optimize the net performance of the photovoltaic (PV) or concentrator photovoltaic (CPV) system equipped with a dual-axis sun tracking system. Parasitic energy loss associated with the power consumption of the sun tracking system is one of the major concerns for the solar industrial players. To address this issue, a comprehensive methodology has been developed to evaluate the yearly cumulative range of motion for dual-axis sun tracking systems in the cases of with and without fixed parking positions across the latitudes ranging from 45°N to 45°S. The parasitic energy consumptions have been investigated for three selected types of dual-axis sun tracking systems, i.e., the azimuth-elevation sun tracking system (AE-STS), polar dual-axis sun tracking system (PD-STS), and horizontal dual-axis sun tracking system (HD-STS). The simulated results indicate that the dual-axis sun tracking system with the nonfixed parking (or stow) position has lower yearly cumulative parasitic energy consumption with respect to the sun tracking system with a fixed parking position. Lastly, our simulation result has shown that the parasitic energy consumption of the sun tracking is relatively smaller to that of the electrical energy generated by the concentrator photovoltaic system with the ratio between 0.15% and 0.29% for AE-STS, between 0.15% and 0.30% for PD-STS, and between 0.17% and 0.35% for HD-STS.

scholarly journals Experimental Study for Energy Dissipation Using Stilling Basin with One and Two Consecutive Drops

2014 ◽  
Vol 7 (2) ◽  
pp. 61-28
Author(s):  
Qassem H. Jalut ◽  
Nagla F. El-Baaja
Keyword(s):  
Energy Loss ◽  
Relative Energy ◽  
Excess Energy ◽  
Relative Height ◽  
Stilling Basin ◽  
Block Height ◽  
Different Types ◽  
Engineering Department ◽  
Bed Slope ◽  
Baffle Block

The scour at downstream of hydraulic structures is one of the major concern in its stability analysis and operation .The excess energy existing immediately downstream of such structures has to be controlled. Hence, it is necessary to design and install a device for dissipating excess energy in order to prevent downstream scour. The drop structures is one of the commonly structures used for dissipating excess energy.In the present study an experimental approach is employed through which different types of stilling basin with different heights were tested using one drop and two consecutive drops. Moreover the effect of the end sill and baffles with different heights and different bed slopes was investigated. The hydraulic parameters involved were measured experimentally using a model of straight drop installed in the available (S6) multi-purpose flume in the fluid mechanics lab at the Civil Engineering Department, University of Garyounis.Results showed that, for one drop the presence of end sill reduced the length of the jump by a small value approximately 4%with an increase of relative energy loss by a small value. The increase of relative baffles block height increases the optimum relative height of drop (w/y1=6), and the relative energy loss .For two consecutive drops it was found that the most value of energy loss takes place in the second basin. The presences of end sill at the end of second basin increases the performance of second basin by small value approximately 5%. It is also shown that increasing the relative height of baffles blocks lead to increases in the relative energy loss (within the ranges considered in this study), and the optimum relative baffle block height hb/y1=0.77 to 1.7 and bed slope is 1/50

scholarly journals PENENTUAN KEHILANGAN ENERGI AKIBAT KEKASARAN DINDING PIPA PADA SISTEM JARINGAN PIPA DENGAN MENGGUNAKAN SOFTWARE WATERCAD V8i

2015 ◽  
Vol 9 (1) ◽  
pp. 32
Author(s):  
Muh Taufik Iqbal
Keyword(s):  
Energy Loss ◽  
Flow Velocity ◽  
Pipe Flow ◽  
Roughness Length ◽  
Piping System ◽  
Cross Sectional ◽  
Application Data ◽  
Smooth Pipe ◽  
Pipe Roughness ◽  
The Difference

Sistem perpipaan berfungsi untuk mengalirkan zat cair dari satu tempat ke tempat yang lain. Aliran terjadi karena adanya perbedaan tinggi tekanan pada kedua tempat, yang biasa terjadi karena adanya perbedaan elevasi muka air atau karena digunakannya pompa. Aliran fluida didalam pipa mengalami kehilangan energi seiring dengan panjang pipa yang dilalui, yang diakibatkan kekasaran pipa, panjang pipa, diameter pipa, dan  jenis fluida.         Tujuan dari penelitian ini adalah untuk mengetahui efek kekasaran dinding pipa terhadap kecepatan aliran dan untuk mengetahui perbedaan antara kecepatan aliran terhadap kekasaran dinding pipa jika menggunakan manometer manual dengan dengan software WaterCad V8i. Pada percobaan ini dilakukan dua percobaan, yaitu percobaan menggunakan manometer manual didalam laboratorium dengan berbagai macam variasi diameter dan jenis pipa yaitu pipa halus dan pipa kasar dengan percobaan menggunakan aplikasi WaterCad V8i. Pada percobaan pipa halus semakin besar nilai kecepatan aliran (0,792 m/s – 3,740 m/s) dalam pipa, maka nilai kehilangan energi (0,028 – 4,813)  juga akan semakin besar. Ini membuktikan bahwa kecepatan aliran berbanding lurus dengan nilai kehilangan energi. Pada percobaan pipa kasar semakin besar nilai kecepatan aliran (0,875 m/s –2,548 m/s) dalam pipa, maka nilai kehilangan energi (0,096 – 0,808)  juga akan semakin besar. Ini membuktikan bahwa kecepatan aliran berbanding lurus dengan nilai kehilangan energi. Bedanya dengan percobaan pada pipa halus adalah kecepatannya lebih besar, ini diakibarkan karena penampang bagian dalam pipa memiliki permukaan yang lebih halus dan memiliki luas penampang yang lebih kecil dibandingkan dengan pipa kasar, dan kecepatan aliran pada pipa kasar  rendah diakibatkan adanya gesekan dengan permukaan pipa yang kasar. Perbandingan menggunakan metode manual dengan menggunakan aplikasi Watercad V8i dari nilai regresi data manual dan data aplikasi (0,787 – 0,975), hasil perhitungan menggunakan aplikasi Watercad V8i; nilai kecepatan dan kehilangan energi yang diperoleh mendekati / memiliki hubungan langsung positip baik dengan nilai kecepatan dan kehilagan energi yang diperoleh dengan menggunakan metode manual.Kata Kunci: Kehilangan Energi, Jaringan Pipa, Watercad V8i Piping system serves to drain liquid from one place to another. Flow occurs due to the high difference in pressure in the second place, that usually happens because of differences in water level or by the use of pumps. Fluid flow in the pipe experience a loss of energy along the length of pipe that passed, which caused the pipe roughness, length of pipe, pipe diameter, and type of fluid.In this study, two experiments, the experiment using a manometer manually in the laboratory with a wide variety of diameters and types of pipe is smooth pipes and plumbing rough and experiments using V8i WaterCad applications.At the trial the greater smooth pipe flow velocity value (0.792 m / s - 3,740 m / s) in the pipeline, then the value of the energy loss (0.028 to 4.813) will also increase. This proves that the flow velocity is proportional to the rate of energy loss. At the trial the greater rough pipe flow velocity value (0.875 m / s -2.548 m / s) in the pipeline, then the value of the energy loss (0.096 to 0.808) will also increase. This proves that the flow velocity is proportional to the rate of energy loss. The difference with experiments on smooth pipe is greater speed, this diakibarkan because the cross section of the inner tube has a smoother surface and has a smaller cross-sectional area compared to the rough plumbing and rough pipe flow velocity at low due to friction with the rough surface of the pipe .Comparison using the manual method using Watercad V8i application of regression value of manual data and application data (0.787 to 0.975), the results of calculations using Watercad V8i application; the value of speed and energy loss obtained approaching / have a direct positive relationship both with speed and kehilagan energy value obtained using the manual method.Keywords: Loss of Energy, Pipeline, Watercad V8i 

scholarly journals Multilevel Inverter for AC Drives with Less Number of Swiches

2019 ◽  
Vol 8 (12S) ◽  
pp. 129-131
Keyword(s):  
Energy Loss ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Voltage Source ◽  
Ac Drives ◽  
Advantages And Disadvantages ◽  
Voltage Stress ◽  
Different Types ◽  
Modulation Voltage ◽  
Voltage Switching

Multilevel inverter plays an important role at today's time. This gives us a good measure of voltage, reduces harmonic integrity, reduces energy loss and also gives us high levels of energy. The different types of topology that are produced takes reduce amount of power, voltage source and voltage switching as compared to traditional topology. This paper focuses on the variety of modes in the multilevel inverter, methods of modulation, voltage stress and how to eliminate the effect of total harmonic distortion. In the end the advantages and disadvantages of the review topology is concluded.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Differentiating between different forms of moral obligations

2020 ◽  
Vol 43 ◽  
Author(s):  
Rajen A. Anderson ◽  
Benjamin C. Ruisch ◽  
David A. Pizarro
Keyword(s):  
Moral Character ◽  
Moral Obligations ◽  
Different Types

Abstract We argue that Tomasello's account overlooks important psychological distinctions between how humans judge different types of moral obligations, such as prescriptive obligations (i.e., what one should do) and proscriptive obligations (i.e., what one should not do). Specifically, evaluating these different types of obligations rests on different psychological inputs and has distinct downstream consequences for judgments of moral character.

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