scholarly journals Numerical modeling of open pit ventilation when varying the location of the dust and gas cloud

2021 ◽  
Vol 1 (7) ◽  
pp. 5-15
Author(s):  
Pavel V. Amosov ◽  
Keyword(s):  
Natural Ventilation ◽  
Vortex Formation ◽  
Aerodynamic Characteristics ◽  
Open Pit ◽  
Contamination Level ◽  
Initial Height ◽  
Component Distribution ◽  
Air Contamination ◽  
Gaseous Component ◽  
Gas Cloud

Research objective is to estimate the effect of bulk explosion location and the initial height of the dust and gas cloud on open-pit natural ventilation time and the level of air contamination of the upper edge of the open pit down the wind. Methods of research. Computer modeling of aerodynamics and gaseous component transfer in the 2D geometry is carried out with the COMSOL software. To calculate the aerodynamic characteristics, the approximation of the incompressible fluid with the standard k–ε turbulence model was carried out. Gaseous component distribution was modeled using the numerical solution to the convection-diffusion equation of contaminant transfer. Numerical experiments under the fixed initial concentration of the gaseous component and the speed of the incoming wind flow have been carried out for three locations of bulk explosions and six values of the initial height (from 70 to 420 m with a step of 70 m) of the dust and gas cloud. Research results and analysis. Spatial distributions of the model’s aerodynamic characteristics and contaminants gaseous component when reaching the maximum permissible concentration in the modeled area have been obtained. The estimated time of the open-pit natural ventilation and the dynamics of the open-pit upper edge air contamination dynamics down the wind have been analyzed. The complex and diversified nature of open pit ventilation for various locations of bulk explosions has been recorded. The undulating character of contaminant loss has been predicted (with different heights of peaks) conditioned by the presence of vortex formation in the open pit. Conclusion and scope of results. For the recirculation scheme of ventilation, the situations with the bulk explosion locations shifted to the windward edge of the open pit are the longest. It has been shown that the reduction in the dust and gas cloud lift does not always ensure the reduction in the contamination level at the upper edge of the open pit down the wind.

DETERMINATION AERODYNAMIC CHARACTERISTICS OF ELEMENTS OF BUILDING VENTILATION SYSTEMS IN LABORATORY CONDITIONS

2021 ◽  
Vol 3 (1) ◽  
pp. 049-053
Author(s):  
M. A. KRIVOSHEIN ◽  
◽  
K. D. SMIRNOV ◽  
K. V. MESHKO ◽  
◽  
...  
Keyword(s):  
Natural Ventilation ◽  
Check Valve ◽  
Aerodynamic Characteristics ◽  
Laboratory Conditions ◽  
Building Ventilation ◽  
Ventilation Systems

The article presents the layout and appearance of the stand, developed to determine the aerodynamic characteristics of the elements of ventilation systems. The technique of determining the aerodynamic characteristics of ventilation elements using the developed stand is considered. The results of tests of a check valve used in natural ventilation systems of buildings are presented. The obtained characteristic of the check valve is proposed to be used in calculating and predicting the operation of ventilation systems in buildings in which the check valves under consideration will be installed

Aerodynamic Characteristics of Asymmetric Bluff Bodies

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
J. C. Hu ◽  
Y. Zhou
Keyword(s):  
Bluff Body ◽  
Laser Doppler Anemometry ◽  
Vortex Formation ◽  
Aerodynamic Characteristics ◽  
Bluff Bodies ◽  
Reynolds Stresses ◽  
Freestream Velocity ◽  
Drag And Lift ◽  
Particle Imaging ◽  
Visualization Techniques

The wake of asymmetric bluff bodies was experimentally measured using particle imaging velocimetry, laser Doppler anemometry, load cell, hotwire, and flow visualization techniques at Re=2600–8500 based on the freestream velocity and the characteristic height of the bluff bodies. Asymmetry is produced by rounding some corners of a square cylinder and leaving others unrounded. It is found that, with increasing corner radius, the flow reversal region is expanded, and the vortex formation length is prolonged. Accordingly, the vortex shedding frequency increases and the base pressure rises, resulting in a reduction in the mean drag as well as the fluctuating drag and lift. It is further found that, while the asymmetric cross section of the cylinder causes the wake centerline to shift toward the sharp corner side of the bluff body, the wake remains globally symmetric about the shifted centerline. The near wake of asymmetric bluff bodies is characterized in detail, including the Reynolds stresses, characteristic velocity, and length scale, and is further compared with that of the symmetric ones.

scholarly journals Air Quality Prediction by Machine Learning

2021 ◽  
pp. 486-492
Author(s):  
Ritik Sharma ◽  
Gaurav Shilimkar ◽  
Shivam Pisal
Keyword(s):  
Machine Learning ◽  
Air Quality ◽  
Urban Areas ◽  
Contamination Level ◽  
Quality Prediction ◽  
Air Contamination ◽  
The Public ◽  
The Past ◽  
Air Quality Prediction ◽  
Future Information

The air quality observing framework estimates different air toxins in different areas to keep up great air quality. It is the consuming issue in the current situation. Air is defiled by the appearance of risky gases into the environment from the enterprises, vehicular outflows, and so forth These days, air contamination has arrived at basic levels and the air contamination level in many significant urban areas has crossed the air quality list esteem as set by the public authority. It significantly affects the soundness of the human. With the headway in innovation of ML, it is currently conceivable to anticipate the poisons dependent on the past information. In this paper we are presenting a gadget that can proceed with that can take present poisons and with the assistance of past toxins, we are running a calculation dependent on the ML to anticipate the future information of contaminations. The detected information is saved inside the Excel sheet for additional assessment. These sensors are utilized on the Arduino Uno stage to gather the contamination information.

scholarly journals Airborne Bacteria and Carcass Contamination in Slaughterhouses

1997 ◽  
Vol 60 (1) ◽  
pp. 38-42 ◽  
Author(s):  
T. MARJATTA RAHKIO ◽  
HANNU J. KORKEALA
Keyword(s):  
Air Flow ◽  
The Other ◽  
Contamination Level ◽  
Airborne Bacteria ◽  
Microbiological Contamination ◽  
Air Contamination ◽  
Airborne Contamination ◽  
Carcass Contamination ◽  
Flow Detector

Microbiological contamination of air and carcasses .was studied in four slaughterhouses by using impactor samples taken at the back-splitting and weighing areas and by sampling carcasses with the swabbing method. Air flow was determined by an air-flow detector, and the movement of workers was observed. The air contamination level in the back-splitting areas (2.25 log CFU/100 liters of air) was generally higher than that in the weighing areas (2.03 log CFU/100 liters of air). Associations between the microbiological contamination of air and carcasses with the movements of workers were found. Layout of the slaughtering line was shown to be important in decreasing airborne contamination. Separation of the clean and unclean parts of the line as well as separation of the weighing area from the other clean parts of the line decreased the contamination level. It appears that airborne bacteria have an important role in carcass contamination.

The impact of natural ventilation on airborne biocontaminants: a study on COVID-19 dispersion in an open office

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Günsu Merin Abbas ◽  
Ipek Gursel Dino
Keyword(s):  
Indoor Air ◽  
Natural Ventilation ◽  
Infection Risk ◽  
Content Type ◽  
Air Contamination ◽  
Simulation Based ◽  
Time Of Infection ◽  
Free Running ◽  
The Impact ◽  
Open Office

PurposeBiocontaminants represent higher risks to occupants' health in shared spaces. Natural ventilation is an effective strategy against indoor air biocontamination. However, the relationship between natural ventilation and indoor air contamination requires an in-depth investigation of the behavior of airborne infectious diseases, particularly concerning the contaminant's viral and aerodynamic characteristics. This research investigates the effectiveness of natural ventilation in preventing infection risks for coronavirus disease (COVID-19) through indoor air contamination of a free-running, naturally-ventilated room (where no space conditioning is used) that contains a person having COVID-19 through building-related parameters.Design/methodology/approachThis research adopts a case study strategy involving a simulation-based approach. A simulation pipeline is implemented through a number of design scenarios for an open office. The simulation pipeline performs integrated contamination analysis, coupling a parametric 3D design environment, computational fluid dynamics (CFD) and energy simulations. The results of the implemented pipeline for COVID-19 are evaluated for building and environment-related parameters. Study metrics are identified as indoor air contamination levels, discharge period and the time of infection.FindingsAccording to the simulation results, higher indoor air temperatures help to reduce the infection risk. Free-running spring and fall seasons can pose higher infection risk as compared to summer. Higher opening-to-wall ratios have higher potential to reduce infection risk. Adjacent window configuration has an advantage over opposite window configuration. As a design strategy, increasing opening-to-wall ratio has a higher impact on reducing the infection risk as compared to changing the opening configuration from opposite to adjacent. However, each building setup is a unique case that requires a systematic investigation to reliably understand the complex airflow and contaminant dispersion behavior. Metrics, strategies and actions to minimize indoor contamination risks should be addressed in future building standards. The simulation pipeline developed in this study has the potential to support decision-making during the adaptation of existing buildings to pandemic conditions and the design of new buildings.Originality/valueThe addressed need of investigation is especially crucial for the COVID-19 that is contagious and hazardous in shared indoors due to its aerodynamic behavior, faster transmission rates and high viral replicability. This research contributes to the current literature by presenting the simulation-based results for COVID-19 as investigated through building-related and environment-related parameters against contaminant concentration levels, the discharge period and the time of infection. Accordingly, this research presents results to provide a basis for a broader understanding of the correlation between the built environment and the aerodynamic behavior of COVID-19.

scholarly journals Investigation of Aerodynamic Characteristics of a Wing Model With RGV Winglet

2020 ◽  
Author(s):  
Sivaraj Gopal Krishnan ◽  
Mohammad Hafifi Ishak ◽  
Mohammad Azwan Nasirudin ◽  
Farzad Ismail
Keyword(s):  
Drag Coefficient ◽  
Lift Coefficient ◽  
Vortex Formation ◽  
Aerodynamic Characteristics ◽  
Contour Plot ◽  
Tip Vortices ◽  
Wing Model ◽  
Plot Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Drag Ratio

This work describes the aerodynamic characteristics of an aircraft wing model with a Rüppell’s griffon vulture (RGV)-type winglet. A computational fluid dynamics (CFD) study using ANSYS 15.0 was conducted to study the effect of the RGV winglet on a rectangular wing. The NACA 65(3)-218 wing consists of 660 mm span and 121 mm chord length where the aspect ratio is 5.45. Eight different winglet configurations have been studied. Furthermore, the study is extended to study effect of cant angle and different angles of attack (AOA) to the winglet. A comparative study is done on aerodynamic features such as lift coefficient (CL), drag coefficient (CD), lift/drag ratio (CL/CD) and tip vortices to get the best RGV winglet design. The RGV winglet achieved highest CL compared to other types of winglets configuration. Based on contour plot analysis, the RGV winglet shows lower vortex formation compared to without winglet. The results show about 15 to 30% reduction in drag coefficient and 5 to 25% increase in lift coefficient by using an RGV winglet.

Design and performance of Factual Time Internet of Things based Geographic Air Pollution Scrutinize System

2020 ◽  
Vol 48 (4) ◽  
pp. 03-04
Author(s):  
Igor Dellucci
Keyword(s):  
Carbon Fixation ◽  
Recent Decade ◽  
Contamination Level ◽  
Simple Shape ◽  
Air Contamination ◽  
Remote Sensor ◽  
Level Data ◽  
And Performance ◽  
The Individual ◽  
Minimal Effort

In the most recent decade, altitude of contamination is dauntless in built-up zone. Because of this, the superiority debases step by step. Air contamination observing is significant idea to check the encompassing air is reasonable to inhalation by the individual or not. In light of expanding the passage pace of carbon fixation present noticeable all around builds which bring about the natural air gets dirtied. Today every person needs to live in the solid climate, they need to check whether the specific zone where they need to go is pretty much contaminated and as per this contamination level data they may pick their course fittingly. Because of this analysts are cantered around air contamination checking assistance of remote sensor organize. These sensor systems give the data of contamination level of the brought together worker utilizing web. This magazine proposed a dependable and minimal effort air contamination checking framework for creating nations. Sensor assortment information in the simple shape and send this computerized information to cloud worker and accumulate the information on cloud workers and afterward progressionof this information. Presently a day's portable are accessible to everybody on the off chance that it might conceivable to check the contamination level of every zone, it might assist them with choosing the other sound course. Different advances are utilized beforehand for checking the contamination level however exactness in the perusing of contamination level tradeoffs. The proposed contamination estimation framework shows minimal effort and better dependability when contrasted with other estimation gadgets that is appeared in reproduction and consequence.

Vortex Breakdown Effects on the Low-speed Aerodynamic Characteristics of Slender Delta Wings in Symmetrical Flow

1967 ◽  
Vol 71 (676) ◽  
pp. 319-322 ◽  
Author(s):  
D. Hummel ◽  
P. S. Srinivasan
Keyword(s):  
Vortex Breakdown ◽  
Vortex Formation ◽  
Vortex Sheet ◽  
Aerodynamic Characteristics ◽  
Flow Visualisation ◽  
Delta Wings ◽  
Vortex Sheets ◽  
The Core ◽  
Leading Edges ◽  
Slender Wing

Even at small angles of incidence, the flow separates from the sharp leading edges of a slender wing. These flow separations usually lead to the formation of two free vortex layers, joined to the leading edges of the wing and rolling up to form spiral-shaped vortex sheets above the upper surface of the wing. This vortex formation is illustrated schematically in Fig. 1. The streamlines on the vortex sheet follow helical paths. Smoke injected near the wing apex for flow visualisation remains concentrated close to the axis of the core of the vortex sheet.

scholarly journals Microbiological Air Contamination in Premises of the Primary Health-care

2013 ◽  
Vol 39 (4) ◽  
pp. 51-58 ◽  
Author(s):  
Ewa Karwowska ◽  
Ewa Miaśkiewicz-Pęska ◽  
Dorota Andrzejewska-Morzuch
Keyword(s):  
Health Care ◽  
Primary Health Care ◽  
Community Health Centers ◽  
Culture Method ◽  
Health Centers ◽  
Contamination Level ◽  
Air Contamination ◽  
Mesophilic Bacteria ◽  
Primary Health ◽  
Adults And Children

Abstract The aim of this research was to evaluate the microbiological indoor air contamination level in chosen facilities of the primary health-care for adults and children. The total numbers of mesophilic bacteria, staphylococci, coli-group bacteria and moulds in both surgery rooms and patients’ waiting rooms were determined. Air samples were collected with a MAS 100 impactor and the concentration of microorganisms was estimated by a culture method. The microbiological air contamination level was diverse: the number of mesophilic bacteria ranged from 320 to 560 CFU/m3, number of staphylococci - 10-305 CFU/m3, coli group bacteria - 0-15 CFU/m3 and moulds - 15-35 CFU/m3. The bacteriological contamination level of the air in examined community health centers was higher than described in the literature for hospitals and exceeded the acceptable values proposed for the surgery objects.

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