scholarly journals Dynamic grit chamber modelling: dealing with particle settling velocity distributions

2020 ◽  
Vol 81 (8) ◽  
pp. 1682-1699 ◽  
Author(s):  
Queralt Plana ◽  
Paul Lessard ◽  
Peter A. Vanrolleghem
Keyword(s):  
Dynamic Model ◽  
Water Resource ◽  
Settling Velocity ◽  
Resource Recovery ◽  
Mass Balances ◽  
Particle Settling ◽  
Inorganic Particles ◽  
Design And Optimization ◽  
Modelling Studies ◽  
The Impact

Abstract Grit chambers are meant to reduce the impact of inorganic particles on equipment and processes downstream. Despite their important role, characterization and modelling studies of these process units are scarce, leading to a lack of knowledge and suboptimal operation. Thus, this study presents the first dynamic model, based on mass balances and particle settling velocity distributions, for use in a water resource recovery facility (WRRF) simulator for design and optimization of grit removal units.

scholarly journals How well-mixed is well mixed? Hydrodynamic-biokinetic model integration in an aerated tank of a full-scale water resource recovery facility

2017 ◽  
Vol 76 (8) ◽  
pp. 1950-1965 ◽  
Author(s):  
Usman Rehman ◽  
Wim Audenaert ◽  
Youri Amerlinck ◽  
Thomas Maere ◽  
Marina Arnaldos ◽  
...  
Keyword(s):  
Water Resource ◽  
Weather Conditions ◽  
Resource Recovery ◽  
Full Scale ◽  
Local Concentration ◽  
Biokinetic Model ◽  
Liquid Phases ◽  
In Series ◽  
The Impact ◽  
Process Level

Current water resource recovery facility (WRRF) models only consider local concentration variations caused by inadequate mixing to a very limited extent, which often leads to a need for (rigorous) calibration. The main objective of this study is to visualize local impacts of mixing by developing an integrated hydrodynamic-biokinetic model for an aeration compartment of a full-scale WRRF. Such a model is able to predict local variations in concentrations and thus allows judging their importance at a process level. In order to achieve this, full-scale hydrodynamics have been simulated using computational fluid dynamics (CFD) through a detailed description of the gas and liquid phases and validated experimentally. In a second step, full ASM1 biokinetic model was integrated with the CFD model to account for the impact of mixing at the process level. The integrated model was subsequently used to evaluate effects of changing influent and aeration flows on process performance. Regions of poor mixing resulting in non-uniform substrate distributions were observed even in areas commonly assumed to be well-mixed. The concept of concentration distribution plots was introduced to quantify and clearly present spatial variations in local process concentrations. Moreover, the results of the CFD-biokinetic model were concisely compared with a conventional tanks-in-series (TIS) approach. It was found that TIS model needs calibration and a single parameter set does not suffice to describe the system under both dry and wet weather conditions. Finally, it was concluded that local mixing conditions have significant consequences in terms of optimal sensor location, control system design and process evaluation.

332-OR: Determining the Impact of Additional Macronutrients on the Glycemic-Insulin Dynamic Model

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 332-OR
Author(s):  
BOYI JIANG ◽  
YUXIANG ZHONG ◽  
PRATIK AGRAWAL ◽  
TONI L. CORDERO ◽  
ROBERT VIGERSKY
Keyword(s):  
Dynamic Model ◽  
The Impact

River-Basin Planning for Control of Nitrate Pollution

1982 ◽  
Vol 14 (4-5) ◽  
pp. 245-252 ◽  
Author(s):  
C S Sinnott ◽  
D G Jamieson
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
River Basin ◽  
Water Resource ◽  
Potable Water ◽  
Potential Problem ◽  
Nitrate Pollution ◽  
Optimal Mix ◽  
Regional Basis ◽  
The Impact

The combination of increasing nitrate concentrations in the River Thames and the recent EEC Directive on the acceptable level in potable water is posing a potential problem. In assessing the impact of nitrates on water-resource systems, extensive use has been made of time-series analysis and simulation. These techniques are being used to define the optimal mix of alternatives for overcoming the problem on a regional basis.

Fundamental Improvements to Anaerobic Digestion Systems at Water Resource Recovery Facilities

2018 ◽  
Vol 2018 (4) ◽  
pp. 353-365
Author(s):  
David Parry ◽  
Cameron Clark ◽  
Corey Kliebert ◽  
Paul Steele
Keyword(s):  
Anaerobic Digestion ◽  
Water Resource ◽  
Resource Recovery

Building an integrated AI and mathmatical modeling framework for online supervision and control of water resource recovery facilities

2018 ◽  
Vol 2018 (10) ◽  
pp. 4025-4028
Author(s):  
Jose Porro ◽  
Chaïm De Mulder ◽  
Youri Amerlinck ◽  
Elena Torfs ◽  
Sophie Balemans ◽  
...  
Keyword(s):  
Water Resource ◽  
Resource Recovery ◽  
Modeling Framework ◽  
Online Supervision ◽  
And Control

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

Influence of the backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set

2016 ◽  
Vol 231 (11) ◽  
pp. 2025-2041 ◽  
Author(s):  
Shijing Wu ◽  
Haibo Zhang ◽  
Xiaosun Wang ◽  
Zeming Peng ◽  
Kangkang Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Planetary Gear ◽  
Tooth Wear ◽  
Transmission Error ◽  
Gear Transmission ◽  
Tooth Surface ◽  
Contact Ratio ◽  
The Impact

Backlash is a key internal excitation on the dynamic response of planetary gear transmission. After the gear transmission running for a long time under load torque, due to tooth wear accumulation, the backlash between the tooth surface of two mating gears increases, which results in a larger and irregular backlash. However, the increasing backlash generated by tooth accumulated wear is generally neglected in lots of dynamics analysis for epicyclic gear trains. In order to investigate the impact of backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set, in this work, first a static tooth surface wear prediction model is incorporated with a dynamic iteration methodology to get the increasing backlash generated by tooth accumulated wear for one pair of mating teeth under the condition that contact ratio equals to one. Then in order to introduce the tooth accumulated wear into dynamic model of compound planetary gear set, the backlash excitation generated by tooth accumulated wear for each meshing pair in compound planetary gear set is given under the condition that contact ratio equals to one and does not equal to one. Last, in order to investigate the impact of the increasing backlash generated by tooth accumulated wear on dynamic response of compound planetary gear set, a nonlinear lumped-parameter dynamic model of compound planetary gear set is employed to describe the dynamic relationships of gear transmission under the internal excitations generated by worn profile, meshing stiffness, transmission error, and backlash. The results indicate that the introduction of the increasing backlash generated by tooth accumulated wear makes a significant influence on the bifurcation and chaotic characteristics, dynamic response in time domain, and load sharing behavior of compound planetary gear set.

scholarly journals From wastewater treatment to water resource recovery: Environmental and economic impacts of full-scale implementation

2021 ◽  
pp. 117554
Author(s):  
Maria Faragò ◽  
Anders Damgaard ◽  
Jeanette Agertved Madsen ◽  
Jacob Kragh Andersen ◽  
Dines Thornberg ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Resource ◽  
Economic Impacts ◽  
Resource Recovery ◽  
Full Scale
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