scholarly journals Hydrodynamic Evaluation of Five Influent Distribution Systems in a Cylindrical UASB Reactor Using CFD Simulations

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3141
Author(s):  
Juan F. Cisneros ◽  
Fabiola Cobos ◽  
Manuel Raul Pelaez-Samaniego ◽  
Usman Rehman ◽  
Ingmar Nopens ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Distribution System ◽  
Distribution Systems ◽  
Uasb Reactor ◽  
The Novel ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Hydrodynamic Evaluation ◽  
The One ◽  
Uasb Reactors

UASB reactors are a promising option for environmentally friendly wastewater treatment due to their reduced carbon footprint and their capacity to treat a variety of wastewater strengths, among other recognized advantages over alternative wastewater treatment systems. The Influent Distribution System (IDS) is a critical structure for generating granules in a UASB reactor since it provides the required flow hydrodynamics for their formation. Thus, the objective of this study was to evaluate and compare the efficiency of five IDS configurations to generate ideal granulation conditions using Computational Fluid Dynamics (CFD) simulations. The IDS configurations were as follows: (C1) single radial inflow, (C2) upward axial inflow, (C3) downward distributed axial inflow, and two novel configurations in the form of (C4) double opposite radial inflow and (C5) downward tangential inflow. The hydrodynamic response of configuration C1 was validated in a physical model with dynamic Froude similitude. The granulation measurement was velocity-based in the reactor reaction zone using steady-state CFD simulations. The novel IDS configuration C4 was the one that resulted in the highest granulation volume, with up to 45.5% of the potential granulation volume of the UASB reactor, in contrast to the IDS C2 that obtained the lowest granulation with only 10.8%. Results confirm that the IDS directly impacts the hydrodynamics of the reactor and that model-based design can be used to ascertain IDS configurations that better promote granulation in UASB reactors.

Layered Model Algorithm and its Application in Fault Detection of Power Distribution Network

2014 ◽  
Vol 644-650 ◽  
pp. 2577-2580
Author(s):  
Xiao Quan Li ◽  
Shuai Liu ◽  
Wei Qun Yang
Keyword(s):  
Fault Detection ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Distribution Network ◽  
Source Distribution ◽  
Power Distribution Network ◽  
Layered Model ◽  
The One ◽  
Model Algorithm

In the case that a single fault occurs on a power feeder in the one-source distribution system, the directional layered model of the network which reflects the layered topological characteristic of the network was built up. Then a new algorithm for fault detection in power distribution network was proposed to locate the faulty sections in distribution feeder network. The algorithm itself as well as its program design is simple. It can be applied to complex distribution systems with multi-sources. It is proved correct by an example.

scholarly journals Evaluation of a one-way airflow system in an animal room based on counts of airborne dust particles and bacteria and measurements of ammonia levels

1989 ◽  
Vol 23 (1) ◽  
pp. 7-15 ◽  
Author(s):  
C. Yamauchi ◽  
T. Obara ◽  
N. Fukuyama ◽  
T. Ueda
Keyword(s):  
Turbulent Flow ◽  
Distribution System ◽  
Distribution Systems ◽  
Dust Particles ◽  
Air Distribution ◽  
Airborne Dust ◽  
Work Space ◽  
Turbulent Airflow ◽  
Contamination Levels ◽  
The One

Air cleanliness in the working area of an animal room equipped with a conventional turbulent flow air distribution systems was compared with that in a similar room fitted with a one-way-flow air distribution system; in this, the supply air flowed from the working area through the racks of cages and was removed from the exhaust side. Before the introduction of animals, the air in the working and exhaust areas of both rooms was ascertained to be Class 100. With animals in situ, however, whereas in the turbulent airflow room both the workspace and exhaust air reached about Class 10 000 (with particle counts, bacterial counts and ammonia levels being almost the same) in the one-way-flow room, the air in the work space only went up to about Class 1000. With the addition of sliding doors or curtains in front of the rack in the one-way-flow room the work space air was maintained at Class 100 with almost no dust particles over 1 μm in size, airborne bacteria or ammonia being detectable. A comparison of all factors measured showed that whereas in the turbulent flow room the contamination of the work space air was 91% of that of the exhaust air, in the one-way-flow room it was only 47%, with curtains added this was reduced to 7% and with sliding doors to only 2%. In the latter case, contamination levels increased markedly on both sides during and immediately after cage changing, but recovered to the pre-cage changing levels within 30 min in the personnel working area and within 60 min on the exhaust side.

Computational Study on Noise of Urban Air Mobility Quadrotor Aircraft

2021 ◽  
Author(s):  
Zhongqi (Henry) Jia ◽  
Seongkyu Lee
Keyword(s):  
Sound Pressure ◽  
Computational Study ◽  
Urban Air ◽  
Noise Levels ◽  
Cfd Simulations ◽  
Community Noise ◽  
Cfd Models ◽  
Quadrotor Aircraft ◽  
Computational Fluid Dynamics Cfd ◽  
The One

This paper investigates the acoustics of a one-passenger and a six-passenger quadrotor urban air mobility (UAM) aircraft in level flight based on a high-fidelity computational fluid dynamics (CFD) approach. The CFD simulations are carried out using the HPCMP CREATETM-AV multidisciplinary rotorcraft analysis and simulation tool Helios. The acoustic simulations are performed using the acoustic prediction tool PSU-WOPWOP. A total of three CFD models are simulated: a one-passenger isolated rotor configuration, a one-passenger full configuration with a fuselage, and a six-passenger isolated rotor configuration. The noise comparison between the one-passenger isolated rotor case and the full configuration case shows that the vehicle fuselage increases the A-weighted sound pressure level (SPL) up to 5 dB. The acoustic comparison between the one-passenger and the six-passenger isolated rotor configuration shows that the maximum overall SPL difference is up to 14 dB. Furthermore, it is shown that the noise of the six-passenger configuration is approximately 11 dB lower than that of a similar-sized conventional helicopter in an overhead scenario. The community noise impact of UAM aircraft is also assessed and compared to various background noise levels. The results show that the one-passenger quadrotor noise can be fully masked by freeway noise at an altitude greater than or equal to 1000 ft, while the six-passenger quadrotor noise can only be partially masked by freeway noise even at an altitude of 1000 ft.

Simple wastewater treatment (UASB reactor, shallow polishing ponds, coarse rock filter) allowing compliance with different reuse criteria

2006 ◽  
Vol 54 (11-12) ◽  
pp. 199-205 ◽  
Author(s):  
M. von Sperling ◽  
J.G.B. de Andrada
Keyword(s):  
Wastewater Treatment ◽  
Suspended Solids ◽  
Uasb Reactor ◽  
E Coli ◽  
Different Types ◽  
Overall Performance ◽  
Uasb Reactors ◽  
Very High ◽  
Potential Use ◽  
Wastewater Treatment Systems

UASB reactors followed by polishing ponds comprise simple and economic wastewater treatment systems, capable of reaching very high removal efficiencies of pathogenic organisms, leading to the potential use of the effluent for unrestricted irrigation. However, for other types of reuse (urban and industrial), ponds are limited in the sense of producing effluents with high suspended solids (algae) concentrations. The work investigates a system with coarse rock filters for polishing the pond effluent. The overall performance of the system is analyzed, together with the potential for different types of reuse. The excellent results obtained (mean effluent concentrations: BOD: 27 mg/L; SS: 26 mg/L; E. coli: 450 MPN/100 mL) indicate the possibility of unrestricted use of the effluent for agriculture and restricted urban and industrial uses, according to WHO and USEPA.

Combining Upflow Anaerobic Sludge Blanket (UASB) Reactors and Submerged Aerated Biofilters for Secondary Domestic Wastewater Treatment

1999 ◽  
Vol 40 (8) ◽  
pp. 71-79 ◽  
Author(s):  
Ricardo Franci Gonçalves ◽  
Vera Lúcia de Araújo ◽  
Vancleide Soeiro Bof
Keyword(s):  
Wastewater Treatment ◽  
Biogas Production ◽  
Energy Requirement ◽  
Treatment Plant ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Hydraulic Load ◽  
Uasb Reactors ◽  
Sludge Production

This work evaluates the theoretical availability of energy and the sludge production in a wastewater treatment plant (WWTP) that associates UASB reactors and submerged aerated biofilters (BF). A comparison among the behaviour of a pilot plant operating under constant hydraulic load (trial 1) and under hourly variation of hydraulic load, with sludge recirculation from the BF to the UASB (trial 2), was carried out. The results show that it is possible to suppress complementary units of thickening and digestion, once the sludge in the bottom of the UASB reaches concentrations of 4,5% TS and 50 to 70% (VS/TS). A comparison of the biogas availability in a WWTP with primary settlers and anaerobic digesters is accomplished. The biogas production in a UASB + BF WWTP is larger than double that produced on the conventional WWTP. The UASB reactor acts on the total COD present in the wastewater (soluble COD + suspended COD), which does not happen in a conventional WWTP (only the suspended COD retained in the primary settler and in the biological sludge is converted to methane). The sludge production, the energy requirement for aeration and the necessary volume for the reactors of the two kinds of WWTP are appraised.

Optimized Design of Wastewater Disinfection Reactors Based on an Artificial Neural Network Metamodel

2016 ◽  
Author(s):  
Wangshu Wei ◽  
Charles N. Haas ◽  
Bakhtier Farouk
Keyword(s):  
Wastewater Treatment ◽  
Design Space ◽  
Sampling Technique ◽  
Optimized Design ◽  
Hydraulic Characteristics ◽  
Cfd Simulations ◽  
Performance Space ◽  
Wastewater Disinfection ◽  
Treatment Facilities ◽  
Computational Fluid Dynamics Cfd

Peracetic acid (PAA) is an emerging disinfectant for the treatment of wastewater. While it would be possible to optimize the design of this system using computational fluid dynamics (CFD), the computational intensity would be high. As an alternative, we show that an Artificial Neutral Network (ANN) based metamodel can approximate the CFD solutions over an 11 dimensional performance space (dimensions, hydraulic characteristics, and chemical kinetics). By sampling the design space using a quasi-random sampling technique, a series of CFD simulations of disinfection characteristics of PAA in a wastewater treatment reactor are carried out. After a training process using 40 different CFD runs are completed, the ANN developed can be used to achieve an optimized design of wastewater treatment facilities with minimal total cost and acceptable disinfection performance efficiency.

Elementy poetyki ludowej w powieści Rzeczy uprzyjemniające. Utopia T. Bołdak-Janowskiej

2020 ◽  
pp. 182-197
Author(s):  
Agnieszka Goral
Keyword(s):  
Fairy Tales ◽  
Text Analysis ◽  
Literary Text ◽  
Source Material ◽  
Human Existence ◽  
The Other ◽  
The Novel ◽  
Literary Works ◽  
The One ◽  
Cultural Features

The aim of the article is to analyse the elements of folk poetics in the novel Pleasant things. Utopia by T. Bołdak-Janowska. The category of folklore is understood in a rather narrow way, and at the same time it is most often used in critical and literary works as meaning a set of cultural features (customs and rituals, beliefs and rituals, symbols, beliefs and stereotypes) whose carrier is the rural folk. The analysis covers such elements of the work as place, plot, heroes, folk system of values, folk rituals, customs, and symbols. The description is conducted based on the analysis of source material as well as selected works in the field of literary text analysis and ethnolinguistics. The analysis shows that folk poetics was creatively associated with the elements of fairy tales and fantasy in the studied work, and its role consists of – on the one hand – presenting the folk world represented and – on the other – presenting a message about the meaning of human existence.

Unit Template Based Control of PV-DSTATCOM

2020 ◽  
Vol 13 (1) ◽  
pp. 36-42
Author(s):  
Gunjan Varshney ◽  
Durg S. Chauhan ◽  
Madhukar P. Dave ◽  
Nitin
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Phase Distribution ◽  
Voltage Regulation ◽  
Photovoltaic Array ◽  
Quality Issues ◽  
Static Compensator

Background: In modern electrical power distribution systems, Power Quality has become an important concern due to the escalating use of automatic, microprocessor and microcontroller based end user applications. Methods: In this paper, power quality improvement has done using Photovoltaic based Distribution Static Compensator (PV-DSTATCOM). Complete simulation modelling and control of Photovoltaic based Distribution Static Compensator have been provided in the presented paper. In this configuration, DSTATCOM is fed by solar photovoltaic array and PV module is also helpful to maintain the DC link voltage. The switching of PV-STATCOM is controlled by Unit template based control theory. Results: The performance of PV-DSTATCOM has been evaluated for Unity Power Factor (UPF) and AC Voltage Control (ACVC) modes. Here, for studying the power quality issues three-phase distribution system is considered and results have been verified through simulation based on MATLAB software. Conclusion: Different power quality issues and their improvement are studied and presented here for harmonic reduction, DC voltage regulation and power factor correction.

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