scholarly journals An experimental and theoretical investigation of flow in a gross pollutant trap

2009 ◽  
Vol 59 (6) ◽  
pp. 1117-1127 ◽  
Author(s):  
J. T. Madhani ◽  
N. A. Kelson ◽  
R. J. Brown
Keyword(s):  
Free Surface ◽  
Cross Sections ◽  
Experimental Approach ◽  
Detailed Comparison ◽  
Cfd Modelling ◽  
Wide Range ◽  
Significant Difference ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Near Wall

Flow through a gross pollutant trap (GPT) with fully blocked screens is investigated experimentally and theoretically using computational fluid dynamics (CFD). Due to the wide range of possible flow regimes, an experimental approach is developed which uses a downstream weir arrangement to control the nature of the flow and the variation in free surface height. To determine the overall flow structure, measurements are taken at a fixed depth throughout the trap with an Acoustic Doppler Velocimeter (ADV), including velocity profile data across three cross sections of the GPT suitable for more detailed comparison with simulations. Observations of the near-wall flow features at the free surface are also taken, due to their likely importance for understanding litter capture and retention in the GPT. Complementary CFD modelling (using Fluent 6.3) is performed using a two-dimensional k−ɛ turbulence model along with either standard wall law boundary conditions or enhanced near-wall modelling approaches. Comparison with experiments suggest that neither CFD modelling approach could be considered as clearly superior to the other, despite the significant difference in near-wall mesh refinement and modelling that is involved. The experimental approach taken here is found useful to control the flow regime in the GPT and further experiments are recommended to study a greater range of flow conditions.

CFD Modelling of Multiphase Flows: An Overview

2003 ◽  
Author(s):  
Rajnish K. Calay ◽  
Arne E. Holdo
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Mathematical Models ◽  
Cfd Modelling ◽  
Two Phase ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Numerical Modeling Of Flows

The Computational Fluid Dynamics (CFD) is now increasingly being used for modeling industrial flows, i.e. flows which are multiphase and turbulent. Numerical modeling of flows where momentum, heat and mass transfer occurs at the interface presents various difficulties due to the wide range of mechanisms and flow scenarios present. This paper attempts to provide a summary of available mathematical models and techniques for two-phase flows. Some comments are also made on the models available in the commercially available codes.

scholarly journals CFD Prediction and Experimental Measurement of Blade Water Coverage in a Diesel Turbocharger

2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
Jun Yao ◽  
Yufeng Yao
Keyword(s):  
Diesel Engine ◽  
Two Phase Flow ◽  
Leading Edge ◽  
Phase Flow ◽  
Cfd Modelling ◽  
Two Phase ◽  
Water Washing ◽  
Numerical Predictions ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd

A turbocharger unit for diesel engine is often equipped with a built-in online water washing system and its performance is not always satisfactory because of efficiency declination due to deposit accumulated on blade surfaces not being washed away. In this study, a systematic approach of using experimental measurements and computational fluid dynamics (CFD) is adopted to analyse liquid/gas two-phase flow associated with a turbocharger water washing system, in order to understand the underlying flow physics. A medium-sized diesel engine turbocharger configuration is chosen for this purpose. Experiments are focussed on blade surface temperature measurements, while CFD modelling with a coupled Eulerian/Lagrangian method is used for capturing the complex gas/liquid two-phase flow behaviours inside the induction duct and the blade passage. It was found that numerical predictions are in a good agreement with experimental data in terms of temperature distributions of the blade leading edge region and water coverage over the blade ring. Other flow features such as the water droplet trajectories and the particle size distributions are also explored and analysed in further details, and they are useful for understanding the deposit removal mechanism.

The Effect of Unequal Admission on the Performance and Loss Generation in a Double-Entry Turbocharger Turbine

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Colin D. Copeland ◽  
Peter J. Newton ◽  
Ricardo Martinez-Botas ◽  
Martin Seiler
Keyword(s):  
Cfd Model ◽  
Significant Drop ◽  
Turbine Wheel ◽  
Aerodynamic Loss ◽  
Reduced Frequency ◽  
Wide Range ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Double Entry ◽  
High Degree

The current work investigates a circumferentially divided turbine volute designed such that each gas inlet feeds a separate section of the turbine wheel. Although there is a small connecting interspace formed between the nozzle and the mixed-flow rotor inlet, this design does well to preserve the exhaust gas energy in a pulsed-charged application by largely isolating the two streams entering the turbine. However, this type of volute design produces some interesting flow features as a result of unequal flows driving the turbine wheel. To investigate the influence of unequal flows, experimental data from the turbocharger facility at Imperial College have been gathered over a wide range of steady-state, unequal admission conditions. These test results show a significant drop in turbine performance with increasing pressure difference between inlets. In addition, the swallowing capacities of each gas inlet are interdependent, thus indicating some flow interaction between entries. To understand the flow physics driving the observed performance, a full 3D computational fluid dynamics (CFD) model of the turbine was created. Results show a highly disturbed flow field as a consequence of the nonuniform admission. From these results, it is possible to identify the regions of aerodynamic loss responsible for the measured performance decrease. Given the unequal flows present in a double-entry design, each rotor passage sees an abrupt change in flow conditions as it rotates spanning the two feeding sectors. This operation introduces a high degree of unsteady flow into the rotor passage even when it operates in steady conditions. The amplitude and frequency of this unsteadiness will depend both on the level of unequal admission and the speed of rotor rotation. The reduced frequency associated with this disturbance supports the evidence that the flow in the rotor passage is unsteady. Furthermore, the CFD model indicates that the blade passage flow is unable to fully develop in the time available to travel between the two different sectors (entries).

QCD at Fixed Order: Processes

2018 ◽  
Author(s):  
John Campbell ◽  
Joey Huston ◽  
Frank Krauss
Keyword(s):  
Hadron Collider ◽  
Detailed Comparison ◽  
Theoretical Description ◽  
Higgs Bosons ◽  
Final States ◽  
Collider Physics ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Fixed Order ◽  
The Subject

At the core of any theoretical description of hadron collider physics is a fixed-order perturbative treatment of a hard scattering process. This chapter is devoted to a survey of fixed-order predictions for a wide range of Standard Model processes. These range from high cross-section processes such as jet production to much more elusive reactions, such as the production of Higgs bosons. Process by process, these sections illustrate how the techniques developed in Chapter 3 are applied to more complex final states and provide a summary of the fixed-order state-of-the-art. In each case, key theoretical predictions and ideas are identified that will be the subject of a detailed comparison with data in Chapters 8 and 9.

Antibiotic Distribution in a Bone Cement Spacer Model

2007 ◽  
Vol 17 (4) ◽  
pp. 218-223 ◽  
Author(s):  
K. Shiramizu ◽  
V. Lovric ◽  
A.M.D. Leung ◽  
W.R. Walsh
Keyword(s):  
Liquid Phase ◽  
Bone Cement ◽  
Cross Sections ◽  
High Dose ◽  
Cement Spacer ◽  
Traditional Technique ◽  
Low Viscosity ◽  
Significant Difference ◽  
Group A ◽  
Medium Viscosity

Purpose To mix high dose antibiotic powder to the bone cement more easily, Hanssen et al reported mixing the antibiotics with the cement during its liquid phase but made no comments about the relevance of cement viscosity and antibiotic distribution. The purpose of this study was to investigate the effect of the cement mixing technique and cement viscosity on the antibiotics distribution in a cement spacer model. Methods Thirty cylindrical models from three groups were examined. Group A was made by mixing the antibiotics with medium viscosity cement prior to adding the liquid monomer (traditional technique). Group B was made by mixing the antibiotics with medium viscosity cement during its liquid phase (Hanssen's technique). Group C was made by traditional technique with low viscosity cement. In all groups 2 g of tetracycline was used. Three 0.1 mm thick cross sections from each spacer model were examined under the fluorescent microscope. The fluorescent spots of tetracycline were calculated automatically in pixels. To evaluate the distribution of the antibiotics in the spacer model, we selected the cross section with the highest number of pixels and the one with the lowest number of pixels from each of the three cross sections and calculated the difference between them. The distribution disequilibrium was compared between group A and B, A and C. Results No significant difference was observed in either comparison. Conclusion The Hanssen's mixing technique can be used when using high dose antibiotics, and either medium or low viscosity cement could be used in terms of antibiotic distribution.

scholarly journals Biochemical and molecular characterization of Alternaria alternata isolates highly resistant to procymidone from broccoli and cabbage

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Bingran Wang ◽  
Tiancheng Lou ◽  
Lingling Wei ◽  
Wenchan Chen ◽  
Longbing Huang ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Single Point ◽  
Sodium Dodecyl ◽  
Cross Resistance ◽  
Molecular Characteristics ◽  
Single Point Mutation ◽  
Wide Range ◽  
Significant Difference ◽  
Leaf Blights ◽  
High Level

AbstractAlternaria alternata, a causal agent of leaf blights and spots on a wide range of hosts, has a high risk of developing resistance to fungicides. Procymidone, a dicarboximide fungicide (DCF), has been widely used in controlling Alternaria leaf blights in China for decades. However, the resistance of A. alternata against DCFs has rarely been reported from crucifer plants. A total of 198 A. alternata isolates were collected from commercial fields of broccoli and cabbage during 2018–2019, and their sensitivities to procymidone were determined. Biochemical and molecular characteristics were subsequently compared between the high-level procymidone-resistant (ProHR) and procymidone-sensitive (ProS) isolates, and also between ProHR isolates from broccoli and cabbage. Compared with ProS isolates, the mycelial growth rate, sporulation capacity and virulence of most ProHR isolates were reduced; ProHR isolates displayed an increased sensitivity to osmotic stresses and a reduced sensitivity to sodium dodecyl sulfate (SDS); all ProHR isolates showed a reduced sensitivity to hydrogen peroxide (H2O2) except for the isolate B102. Correlation analysis revealed a positive cross-resistance between procymidone and iprodione, or fludioxonil. When treated with 10 μg/mL of procymidone, both mycelial intracellular glycerol accumulations (MIGAs) and relative expression of AaHK1 in ProS isolates were higher than those in ProHR isolates. Sequence alignment of AaHK1 from ten ProHR isolates demonstrated that five of them possessed a single-point mutation (P94A, V612L, E708K or Q924STOP), and four isolates had an insertion or a deletion in their coding regions. No significant difference in biochemical characteristics was observed among ProHR isolates from two different hosts, though mutations in AaHK1 of the cabbage-originated ProHR isolates were distinct from those of the broccoli-originated ProHR isolates.

scholarly journals Flow and Particle Modelling of Dry Powder Inhalers: Methodologies, Recent Development and Emerging Applications

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 189
Author(s):  
Zhanying Zheng ◽  
Sharon Shui Yee Leung ◽  
Raghvendra Gupta
Keyword(s):  
Dry Powder Inhaler ◽  
Research Direction ◽  
Particle Methods ◽  
Future Research ◽  
High Dose ◽  
Dry Powder ◽  
Multi Scale ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Discrete Element Methods

Dry powder inhaler (DPI) is a device used to deliver a drug in dry powder form to the lungs. A wide range of DPI products is currently available, with the choice of DPI device largely depending on the dose, dosing frequency and powder properties of formulations. Computational fluid dynamics (CFD), together with various particle motion modelling tools, such as discrete particle methods (DPM) and discrete element methods (DEM), have been increasingly used to optimise DPI design by revealing the details of flow patterns, particle trajectories, de-agglomerations and depositions within the device and the delivery paths. This review article focuses on the development of the modelling methodologies of flow and particle behaviours in DPI devices and their applications to device design in several emerging fields. Various modelling methods, including the most recent multi-scale approaches, are covered and the latest simulation studies of different devices are summarised and critically assessed. The potential and effectiveness of the modelling tools in optimising designs of emerging DPI devices are specifically discussed, such as those with the features of high-dose, pediatric patient compatibility and independency of patients’ inhalation manoeuvres. Lastly, we summarise the challenges that remain to be addressed in DPI-related fluid and particle modelling and provide our thoughts on future research direction in this field.

scholarly journals Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

2021 ◽  
Vol 9 (4) ◽  
pp. 839
Author(s):  
Muhammad Rafiullah Khan ◽  
Vanee Chonhenchob ◽  
Chongxing Huang ◽  
Panitee Suwanamornlert
Keyword(s):  
Antifungal Activity ◽  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Colletotrichum Acutatum ◽  
Model Parameters ◽  
Pathogenicity Test ◽  
Agar Diffusion ◽  
Wide Range ◽  
Significant Difference ◽  
Diffusion Assay

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R2, 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.

scholarly journals A Threat of Farmers’ Suicide and the Opportunity in Organic Farming for Sustainable Agricultural Development in India

2019 ◽  
Vol 11 (8) ◽  
pp. 2400 ◽  
Author(s):  
Karthikeyan Mariappan ◽  
Deyi Zhou
Keyword(s):  
Organic Farming ◽  
Tamil Nadu ◽  
Agricultural Development ◽  
Small Scale ◽  
Conventional Farming ◽  
Wide Range ◽  
Significant Difference ◽  
Small Scale Farmers ◽  
The Cost ◽  
Input Cost

Agriculture is the main sources of income for humans. Likewise, agriculture is the backbone of the Indian economy. In India, Tamil Nadu regional state has a wide range of possibilities to produce all varieties of organic products due to its diverse agro-climatic condition. This research aimed to identify the economics and efficiency of organic farming, and the possibilities to reduce farmers’ suicides in the Tamil Nadu region through the organic agriculture concept. The emphasis was on farmers, producers, researchers, and marketers entering the sustainable economy through organic farming by reducing input cost and high profit in cultivation. A survey was conducted to gather data. One way analysis of variance (ANOVA) has been used to test the hypothesis regards the cost and profit of rice production. The results showed that there was a significant difference in profitability between organic and conventional farming methods. It is very transparent that organic farming is the leading concept of sustainable agricultural development with better organic manures that can improve soil fertility, better yield, less input cost and better return than conventional farming. The study suggests that by reducing the cost of cultivation and get a marginal return through organic farming method to poor and small scale farmers will reduce socio-economic problems such as farmers’ suicides in the future of Indian agriculture.

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