scholarly journals Investigation of Airflow Distribution and Contamination Control with Different Schemes in an Operating Room

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1639
Author(s):  
Fujen Wang ◽  
Indra Permana ◽  
Dibakar Rakshit ◽  
Bowo Yuli Prasetyo
Keyword(s):  
Operating Room ◽  
Medical Equipment ◽  
Cfd Simulation ◽  
Measurement Data ◽  
Average Concentration ◽  
Ideal Condition ◽  
Contamination Control ◽  
Average Value ◽  
Airflow Distribution ◽  
Ventilation Efficiency

Controlling contamination via proper airflow distribution in an operating room becomes vital to ensure the reliable surgery process. The heating, ventilation, and air conditioning (HVAC) systems significantly influence the operating room environment, including temperature, relative humidity, pressurization, particle counts, filtration, and ventilation rate. A full-scale operating room has been investigated extensively through field measurements and numerical analyses. Computational fluid dynamics (CFD) simulation was conducted and verified with the field measurement data. The simulation was analyzed with three different operating room schemes, including at-rest conditions (case 1), normal operational conditions with personnel (case 2), and actual conditions with personnel inside and some medical equipment blocking the return air (case 3). The concentration decay method was used to evaluate this study. The results revealed that the contamination concentration in case 1 could be diluted quickly with the average value of 404 ppm, whereas the concentration in case 2 slightly increased while performing a surgery with the average value of 420 ppm. The return air grilles in case 3, blocked by obstacles from some medical equipment, resulted in the average concentration value of 474 ppm. Other than that, the contaminant dilution could be obstructed dramatically, which revealed that proper and smooth airflow distribution is essential for contamination control. The ventilation efficiency of case 2 and case 3 dropped around 6% and 17.91% compared to case 1 in the unoccupied and ideal condition. Ventilation efficiency also decreased along with decreasing the air change rate per hour (ACH), while with increasing ACH, the ventilation efficiency in case 3 actually increased, approaching case 2 in the ideal condition.

scholarly journals CFD Simulation of the Airflow Distribution Inside Cube-Grow

CFD Letters ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 81-89
Author(s):  
Arina Mohd Noh ◽  
Hamdan Mohd Noor ◽  
Fauzan Ahmad
Keyword(s):  
Plant Growth ◽  
Urban Agriculture ◽  
Cfd Simulation ◽  
Measurement Data ◽  
Actual Measurement ◽  
Airflow Distribution ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Urban People ◽  
Air Hole

Cube-Grow was developed by MARDI to promote urban agriculture to the urban population. The product enables urban people to grow their vegetables with limited space. The initial test run of the system shows that the plant growth inside the structure was below expectation. The problem arises due to a lack of airflow or improper ventilation inside the structure. Optimum ventilation or airflow is crucial for plant growth as it enhances evapotranspiration at the leaf area to promote optimum plant growth. Therefore, this study aims to increase the airflow inside the Cube-Grow and find the best location for the air hole. Computational fluid dynamics (CFD) simulation was used in this study the analyse the effect of adding an air hole to the airflow characteristic inside the Cube-Grow. CFD also was used to select the best location to place the air hole. 3 option of air hole location was analysed and the results were compared with the existing design. The initial CFD simulation results were compared with the actual measurement data before it was used for further analysis. The result shows that adding an air hole increases overall airflow inside the Cube-Grow. Option 3 was chosen as the best location for the air hole as it produces a uniform and higher airflow inside the Cube-Grow. The study proved that CFD was able to be used to optimize the design of Cube-Grow before the actual prototype was built.

Improvement of the Indoor Environment and Airborne Contamination Control in an Operating Room

2011 ◽  
Vol 255-260 ◽  
pp. 1532-1536
Author(s):  
Fu Jen Wang ◽  
Yat Huang Yau ◽  
Wen Bin Ng ◽  
Chi Ming Lai
Keyword(s):  
Operating Room ◽  
Indoor Environment ◽  
High Efficiency ◽  
Air Distribution ◽  
Contamination Control ◽  
Airflow Distribution ◽  
Strategic Approach ◽  
Airborne Contamination ◽  
Ventilation Performance ◽  
Contamination Concentration

Modern operating rooms are increasingly turning to contamination control by ventilating technology for the infectious control. The objective of this study is to present the strategic approach on performance improvement of the ventilating system for a hospital operating room under limit budget. A physical partition curtain has been proposed and conducted around the high efficiency particulate air (HEPA) filter of an operating room to validate the improvement of air distribution and contamination control. Numerical simulation of a full-scale operating room has been carried out at a district hospital. The results from computer simulation revealed that the improvement of airflow could be achieved satisfactorily by the application of a physical partition curtain at the length of 1.2 m. Ventilation performance could be assessed extensively not only by airflow distribution and concentration profile but also by the calculation of contamination concentration decay.

scholarly journals Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

2020 ◽  
Author(s):  
Xiaoyu Wang ◽  
Peng Liu ◽  
Gongwen Xu
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Measurement Data ◽  
Ground Temperature ◽  
Rapid Urbanization ◽  
Actual Measurement ◽  
Heritage Sites ◽  
Human Thermal Comfort ◽  
The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

scholarly journals Taxonomy of Surgical Delay Related to Sterile Processing and Domino Effect

2019 ◽  
Vol 8 (1) ◽  
pp. 291-295
Author(s):  
Kimberly A. LaForge ◽  
Helen J. A. Fuller ◽  
Timothy Arnold ◽  
Kristin Chrouser ◽  
William Gunnar
Keyword(s):  
Operating Room ◽  
Medical Equipment ◽  
Domino Effect ◽  
Staff Time ◽  
Surgical Delay ◽  
Wide Range ◽  
Competing Demands ◽  
Instructions For Use ◽  
Sterile Processing ◽  
Work Done

Successful surgery does not just depend on the skills and knowledge of those in the operating room but also on the staff that insure the needed instrumentation is available and sterile. The process that continuously provides reusable medical equipment (RME) to the Operating Room (OR) requires highly specialized expertise over a wide range of instrumentation. The reprocessing team must be familiar with instructions for use (IFU), and how to apply them to process every piece of RME from surgeries, endoscopies, and clinic procedures. Coupled with the limitations of staff, time, and resources and with competing demands to produce sterile instruments and environments that work in almost total isolation from each other, there are several gaps in the process that must be identified and bridged. While the workflow for moving between the Sterile Processing Department (SPD) and the OR is sometimes thought as a fairly simple circular flowchart, the realities of work done versus work imagined are vastly different. In addition, these challenges vary considerably across different departments, even in a single healthcare system, and as such there are no simple solutions. Understanding the demands on the SPD, the needs in the OR for sterile RME, and the patient safety concerns that drive this cycle are critical if we are to improve the process.

CFD Simulation of the Losses in an Inlet Guide Vane of a Transonic Test Turbine

2004 ◽  
Author(s):  
W. Sanz ◽  
P. Pieringer ◽  
W. Baumgartner ◽  
W. Edelbauer ◽  
C. Pilz ◽  
...  
Keyword(s):  
Total Pressure ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Measurement Data ◽  
Secondary Flows ◽  
Inlet Guide Vane ◽  
Commercial Code ◽  
Turbine Guide Vane ◽  
Gap Height ◽  
Generation Mechanisms

In this work the flow through a pre-swirl turbine guide vane was calculated using two different flow solvers and compared with total pressure measurements in a downstream plane. The flow is transonic and strongly influenced by secondary flows. A special feature of this cascade is that the gap height at the hub is varying. Flow separation and leakage vortex flow dominate the loss generation. The flow is simulated using an in-house CFD code as well as the commercially available code FLUENT. The flow is carefully analysed and the loss generation mechanisms are presented in detail. The comparison with the measured total pressure distribution shows that the overall loss scheme is well predicted by both codes, but there are still large deficiencies in the quantitative results. The commercial code FLUENT is closer to the measurement data. Further investigations are performed to find out the differences between both codes.

scholarly journals Investigation of an Innovative Rotor Modification for a Small-Scale Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Airflow Distribution

This paper presents the results of the computational fluid dynamics (CFD) simulation of the airflow for a 300 W horizontal axis wind turbine, using additional structural elements which modify the original shape of the rotor in the form of multi-shaped bowls which change the airflow distribution. A three-dimensional CAD model of the tested wind turbine was presented, with three variants subjected to simulation: a basic wind turbine without the element that modifies the airflow distribution, a turbine with a plano-convex bowl, and a turbine with a centrally convex bowl, with the hyperbolic disappearance of convexity as the radius of the rotor increases. The momentary value of wind speed, recorded at measuring points located in the plane of wind turbine blades, demonstrated an increase when compared to the base model by 35% for the wind turbine with the plano-convex bowl, for the wind speed of 5 m/s, and 31.3% and 49% for the higher approaching wind speed, for the plano-convex bowl and centrally convex bowl, respectively. The centrally convex bowl seems to be more appropriate for higher approaching wind speeds. An increase in wind turbine efficiency, described by the power coefficient, for solutions with aerodynamic bowls was observed.

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