scholarly journals Installation of physical simulation of wind load on crane structures

2021 ◽  
Vol 24 (6) ◽  
pp. 1199-1208
Author(s):  
L. A. Sladkova ◽  
V. V. Krylov ◽  
F. A. Kuznetsov
Keyword(s):  
Computer Model ◽  
Physical Simulation ◽  
Flow Simulation ◽  
Dynamic Effect ◽  
Wind Load ◽  
Operating Conditions ◽  
Model Parameters ◽  
Wind Flow ◽  
Operation Conditions ◽  
The Impact

The purpose of the paper is to reproduce a standard wind flow (laminar, turbulent, pulsating modes) to study the impact on crane structures, with the aim to obtain the load values of crane elements most closely approximate to real conditions. When creating an installation, which is related to the field of experimental aerodynamics, the "principle of simulating the main factors determined by the operating conditions of the research object" is adopted to ensure the r eproducibility of test results to the maximum extent. To confirm the performance efficiency of the proposed installation device, its computer model is developed using the CAD software SolidWorks. The computer model parameters are in full geometric agreement with the dimensions of the developed real installation. The use of the installation makes it possible to study the dynamic effect of the wind on the stability of crane structures in various operation modes (change in wind speed, in the mode of load operation, in operation conditions at the wall, etc.). The proposed installation allows to simulate the loads on crane equipment with the possibility of characteristics expanding, for example, its carrying capacity. The generated computer model of the installation makes it possible to reveal the physical picture of wind flow distribution at the installation outlet. The results of wind flow simulation on the proposed installation are confirmed on a computer model with a high degree of convergence of results at wind speeds of 2.5 m/s and lower The installation proposed by the authors will allow to simulate: the value of the real average statistical wind load of various intensity; pulsating component of the wind load; vortex excitation; increase of the available aerodynamic research capability for a real crane structure. The developed installation is a calibration device for external impacts of the wind force on the crane structure.

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

Simulation for a Floating Roof Behavior of Cylindrical Storage Tank due to Wind Load: Part 1 — CFD Analysis

2012 ◽  
Author(s):  
Shinichi Kuroda ◽  
Hidesaku Uejima ◽  
Kazuo Ishida ◽  
Shoichi Yoshida ◽  
Masaki Shiratori ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Storage Tank ◽  
Fatigue Cracks ◽  
Flow Simulation ◽  
Wind Load ◽  
Sea Surface ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
Wind Flow ◽  
Oil Storage

Floating roofs are used in large cylindrical storage tanks to prevent evaporation of oil. The floating roof is said to vibrate in high winds like undulation of the sea surface. The wind induced, sea-surface-undulation-like vibration may initiate fatigue cracks at welded joints in the floating roof deck. In this two-part study, the authors attempted to simulate the vibration. In Part1 wind flow over an isolated cylindrical oil-storage tank was simulated without considering the motion of the roof. Computed unsteady pressure load data were transferred to structural analyses. Response analyses of the floating roof under the wind load are dealt with in Part2. The present paper describes the wind flow simulation. The computed pressure fluctuation over the roof exhibits broadband spectra and no remarkable dominant frequency. To gain some insights into characteristics of the roof pressure fluctuation and its association with global flow structures, the Snapshot Proper Orthogonal Decomposition (POD), the Dynamic Mode Decomposition (DMD), and the Complex POD were applied.

scholarly journals Estimating Caprock Impact on CO2 Migration in the Gassum Formation Using 2D Seismic Line Data

2021 ◽  
Author(s):  
Odd Andersen ◽  
Anja Sundal
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Flow Simulation ◽  
Small Scale ◽  
Model Parameters ◽  
Seismic Line ◽  
Migration Direction ◽  
3D Data ◽  
And Migration ◽  
The Impact

AbstractRealizable CO2 storage potential for saline formations without closed lateral boundaries depends on the combined effects of physical and chemical trapping mechanisms to prevent long-term migration out of the defined storage area. One such mechanism is the topography of the caprock surface, which may retain CO2 in structural pockets along the migration path. Past theoretical and modeling studies suggest that even traps too small to be accurately described by seismic data may play a significant role. In this study, we use real but scarce seismic data from the Gassum Formation of the Norwegian Continental shelf to estimate the impact of topographical features of the top seal in limiting CO2 migration. We seek to estimate the amount of macro- and sub-scale trapping potential of the formation based on a few dozen interpreted 2D seismic lines and identified faults. We generate multiple high-resolution realizations of the top surface, constructed to be faithful to both large-scale topography and small-scale statistical properties. The structural trapping and plume retardation potential of these top surfaces is subsequently estimated using spill-point (static) analysis and dynamical flow simulation. By applying these techniques on a large ensemble of top surface realizations generated using a combination of stochastic realizations and systematic variation of key model parameters, we explore the range of possible impacts on plume advancement, physical trapping and migration direction. The stochastic analysis of trapping capacity and retardation efficiency in statistically generated, sub-seismic resolution features may also be applied for surfaces generated from 3D data.

scholarly journals An Enhanced Electrocoagulation Process for the Removal of Fe and Mn from Municipal Wastewater Using Dielectrophoresis (DEP)

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 485
Author(s):  
Abdulkarim Almukdad ◽  
Alaa H. Hawari ◽  
MhdAmmar Hafiz
Keyword(s):  
Municipal Wastewater ◽  
Operating Conditions ◽  
Electrode Configuration ◽  
Electrode Spacing ◽  
Electrolysis Time ◽  
Applied Current ◽  
Operation Conditions ◽  
Fe And Mn ◽  
Electrocoagulation Process ◽  
The Impact

In this study the removal of Fe and Mn from primary treated municipal wastewater using a new electrode configuration in electrocoagulation was evaluated. The used electrode configuration induced a dielectrophoretic (DEP) force in the electrocoagulation process. The impact of the electrolysis time, electrodes spacing and applied current on the removal of Fe and Mn was evaluated. The maximum removal percentages of Fe and Mn were obtained using an electrolysis time of 60 min, an electrode spacing of 0.5 cm and an applied current of 800 mA. Under these operating conditions and using the new electrodes configuration, the Fe and Mn removals were 96.8% and 66%, respectively. The main advantage of using the DEP-induced electrode configuration was the minimal consumption of the electrodes. The new electrode configuration showed 42% less aluminum content in the reactor compared to the aluminum electrodes with no DEP effect. The energy consumption at the selected operation conditions was 4.88 kWh/m3. The experimental results were comparable with the simulation results achieved by the COMSOL software.

scholarly journals Effects of Flow Baffles on Flow Profile, Pressure Drop and Classification Performance in Classifiers

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1213
Author(s):  
Michael Betz ◽  
Marco Gleiss ◽  
Hermann Nirschl
Keyword(s):  
Pressure Loss ◽  
Collection Efficiency ◽  
Flow Behavior ◽  
Classification Performance ◽  
Operating Conditions ◽  
Flow Profile ◽  
Discrete Phase Model ◽  
Operation Conditions ◽  
Air Classifier ◽  
The Impact

This paper presents a study of the use of flow baffles inside a centrifugal air classifier. An air classifier belongs to the most widely used classification devices in mills in the mineral industry, which is why there is a great interest in optimizing the process flow and pressure loss. Using Computational Fluid Dynamics (CFD), the flow profile in a classifier without and with flow baffles is systematically compared. In the simulations, turbulence effects are modeled with the realizable k–ε model, and the Multiple Reference Frame approach (MRF) is used to represent the rotation of the classifier wheel. The discrete phase model is used to predict the collection efficiency. The effects on the pressure loss and the classification efficiency of the classifier are considered for two operating conditions. In addition, a comparison with experimental data is performed. Firstly, the simulations and experiments show good agreement. Furthermore, the investigations show that the use of flow baffles is suitable for optimizing the flow behavior in the classifier, especially in reducing the pressure loss and therefore energy costs. Moreover, the flow baffles have an impact on the classification performance. The impact depends on the operation conditions, especially the classifier speed. At low classifier speeds, the classifier without flow baffles separates more efficiently; as the speed increases, the classification performance of the classifier with flow baffles improves.

Research on the Optimization Design of Gas-Solid Coupling of Wind Turbine Blades

2014 ◽  
Vol 1022 ◽  
pp. 143-146
Author(s):  
Zhi Qiang Xu
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Optimization Design ◽  
Turbine Blades ◽  
Wind Load ◽  
Rotor Blades ◽  
Model Parameters ◽  
Surface Pressure Distribution ◽  
The Law ◽  
The Impact

The effects of high-altitude wind shear of wind speed should be considered, the appropriate number of distribution group should be determined and the distribution of wind speed hybrid model parameters and solving should be loaded onto the blades. When the stress of rotor blade is analyzed, the elastic deformation of the blades and the effects of the vibration of oscillating flow field on reaction of the blades must be considered during the operation. Thus the laws of blade load distribution and the corresponding deformation can be accurately calculated to analyze the interplay between deformation vibration airflow and paddle, to determine the law of deformation of rotor blades, the surface pressure distribution, stress distribution and blade design safety factors. When wind load changes with the wind speed, the adaptive blades are powered by aeroelastic, the law of wielding and flapping of the blade will be studied. The torsion coupling effects of adaptive blade, blade bending ,the law of torsional deformation variation of the angle of attack and the impact on aeroelastic blades structural strength will be explored. The results of this study design will be optimized as the power factor, improving the stability of the design of wind turbine power output, reducing material consumption blades absorb vibration and reducing wind load maneuvering to avoid blade stall achieve pitch control. Thus it provides a theoretical basis for optimal design of strength and stiffness of the elongated paddles.

Analysis of the Impact of Uncertainties in Inputs on CFD Predictions of Gasoline Compression Ignition

2016 ◽  
Author(s):  
Janardhan Kodavasal ◽  
Stephen Ciatti ◽  
Sibendu Som
Keyword(s):  
Cfd Simulation ◽  
Initial Conditions ◽  
Combustion Process ◽  
Chemical Kinetic ◽  
Operating Conditions ◽  
Model Parameters ◽  
Compression Ignition ◽  
Cfd Model ◽  
Kinetic Rates ◽  
The Impact

Computational fluid dynamics (CFD) is a valuable tool to gain insights into the combustion process, particularly for novel engine combustion concepts that do not have significant experimental data available. However, prediction of targets of interest from a CFD simulation can oftentimes be quite sensitive to the uncertainties in inputs to the CFD model. These uncertainties could be in the experimental boundary and initial conditions, fuel properties, CFD model constants, chemical kinetic rates, etc. In this work we isolate the effect of uncertainties in some key inputs in the form of experimental boundary conditions and CFD model parameters on combustion and emissions targets of interest for gasoline compression ignition (GCI) at two operating conditions — idle, and low-load. The uncertainties in the subset of inputs studied in this work were identified to have the greatest impact out of 34 inputs to the CFD model studied by means of a global sensitivity analysis (GSA) performed in our prior work. The goal of this study is to perform a more focused study as a follow-on to that GSA, by perturbing only a single parameter at a time.

scholarly journals Energy analysis of an ultrasound-assisted atmospheric freeze-drying process for food

2018 ◽  
Author(s):  
Juan A. Cárcel ◽  
Daniele Merone ◽  
Domenico Colucci ◽  
Davide Fissore ◽  
Neus Sanjuán
Keyword(s):  
Energy Consumption ◽  
Freeze Drying ◽  
Operating Conditions ◽  
Model Parameters ◽  
Dehydration Process ◽  
Drying Process ◽  
Water Diffusivity ◽  
Ultrasound Assisted ◽  
The Impact ◽  
Air Dryer

Power ultrasounds have been proposed and extensively investigated as an effective way to speed up the atmospheric freeze-drying process, thus making this dehydration process attractive from an industrial viewpoint. Nevertheless, a rigorous investigation on the impact of power ultrasounds on the energy consumed by the process is still missing. This paper aims to investigate this issue. Apple, carrot and eggplant were chosen as representative products with different textures and water content. A mathematical model of the whole plant required to carry out the atmospheric ultrasound-assisted drying process was developed to assess the effect of the operating conditions on the energy consumption. Model parameters were tuned on the basis of the results obtained in a pilot-scale unit, thus allowing the use of the model to simulate the whole industrial dehydration process. Life Cycle Assessment (LCA) was used as a complementary tool to gain an insight on the environmental impact of the process. Results showed that due to differences in the water diffusivity for the analyzed products, substantial differences in energy consumption can be highlighted. In fact, when the water diffusivity increases, the capacity of the material to move water away also increases and the time to obtain a dry product is thus reduced. Moreover, although the use of ultrasound causes an increase in the hourly energy consumption (kWh·h-1), the total energy consumption of the whole process (kWh) is lower, since the total operation time is reduced. The LCA results highlighted the cooling system as the most critical stage for all the impact categories studied. This is mainly due to the use of ethylene glycol and R-404 in the refrigeration cycle. Nevertheless, when dehydrating low porosity products the energy consumption of the air dryer increased and this stage becomes, the most critical from an environmental point of viewKeywords: atmospheric freeze-drying, ultrasounds, process modeling, LCA.

Research on Sintering Polytechnic of PTFE/Al Reactive Materials

2013 ◽  
Vol 820 ◽  
pp. 25-29
Author(s):  
Jing Bo Wu ◽  
Mao Quan Li ◽  
Shu Hai Zhang ◽  
Yun Long Mei ◽  
Ze Tao Gao
Keyword(s):  
Sintering Temperature ◽  
Operating Conditions ◽  
Process Time ◽  
Sintering Process ◽  
Influence Of Process Parameters ◽  
Reactive Material ◽  
Operation Conditions ◽  
Heat Preservation ◽  
The Impact ◽  
Microstructure Of The Material

PTFE/Al reactive material was prepared via a hot pressed sintering process and comparative experiments were conveyed considering heating rate, sintering temperature and heat preservation time. The internal microstructure of the material was investigated using metallurgical microscope and stereomicroscope. From the investigation the influence of process parameters of hot pressed sintering on the properties of the material were deduced, and the analysis was verified by testing the impact initiation property with drop hammer method. The density of the material was measured according to the Archimedean principle. and the results showed that the best operating conditions of these three factors are 80°C/h, 365°C, and 0.5h, This new method has a higher effectively (short process time) and need lower operation conditions (low sintering temperature and pressure) comparing with the traditional cold sintering process.

scholarly journals A Validation/Uncertainty Quantification Analysis for a 1.5 MW Oxy-Coal Fired Furnace: Sensitivity Analysis

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Oscar H. Díaz-Ibarra ◽  
Jennifer Spinti ◽  
Andrew Fry ◽  
Benjamin Isaac ◽  
Jeremy N. Thornock ◽  
...  
Keyword(s):  
Heat Flux ◽  
Sensitivity Analysis ◽  
Uncertainty Quantification ◽  
Complex Geometry ◽  
Heat Removal ◽  
Operating Conditions ◽  
Model Parameters ◽  
Reacting Flow ◽  
Simulation Data ◽  
The Impact

A validation/uncertainty quantification (VUQ) study was performed on the 1.5 MWth L1500 furnace, an oxy-coal fired facility located at the Industrial Combustion and Gasification Research Facility at the University of Utah. A six-step VUQ framework is used for studying the impact of model parameter uncertainty on heat flux, the quantity of interest (QOI) for the project. This paper focuses on the first two steps of the framework. The first step is the selection of model outputs in the experimental and simulation data that are related to the heat flux: incident heat flux, heat removal by cooling tubes, and wall temperatures. We describe the experimental facility, the operating conditions, and the data collection process. To obtain the simulation data, we utilized two tools, star-ccm+ and Arches. The star-ccm+ simulations captured flow through the complex geometry of the swirl burner while the Arches simulations captured multiphase reacting flow in the L1500. We employed a filtered handoff plane to couple the two simulations. In step two, we developed an input/uncertainty (I/U) map and assigned a priority to 11 model parameters based on prior knowledge. We included parameters from both a char oxidation model and an ash deposition model in this study. We reduced the active parameter space from 11 to 5 based on priority. To further reduce the number of parameters that must be considered in the remaining steps of the framework, we performed a sensitivity analysis on the five parameters and used the results to reduce the parameter set to two.

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