In-duct ultraviolet germicidal irradiation systems are effective that used in disinfection of pathogenic particles transported by air moving through the ventilation systems. Proper design these is quite important for energy consumption and performance. In this study, effect four different lamp arrays within a square cross-section duct on average UV dose, dose distribution rate examined using computational fluid dynamics. The standard k-ε turbulence model discrete phase modeling to analyze...

The aim of this study is to investigate dispersion and deposition characteristics different particle diameters (0.5–5–10 μm) for a displacement ventilated floor heated environment, experimentally numerically. experiments are performed in reduced scale model with the operating parameters determined regarding similarity. Results used validate simulation outputs obtained via Eulerian-Lagrangian method. Three outlet opening configurations source heights considered. compared terms air change...

In this study, effect of inlet/outlet configurations on the dispersion and removal fine particles are examined experimentally numerically. Ten different tested for three contaminant release cases as by incoming air, from breathing level close to outlet. Air velocity distributions, air change efficiency, effectiveness particle decay investigated each case. Results revealed that both inlet outlet opening positions have a strong impact performance ventilation system. The highest efficiency is...

Operating room ventilation is quite important to protect patients from infection risk inside a surgical field. The laminar flow units (LAF) used in these applications contribute removal of pathogen particles the operation area by creating protection zone on In this study, effect LAF diffuse size airflow and particle distribution an operating investigated using computational fluid dynamics (CFD). Three different diffuser sizes (1.8 m x 2.4 m, 3.2 m) three diameters (5 µm, 10 20 µm) are...

In this study, effect of air change rate (air per hour – ACH) on indoor particle dispersion and deposition in a ventilated room is investigated. A reduced-scale model designed to conduct experiments. Numerical predictions are performed by using the commercial software ANSYS Fluent 16.0. Four different values (1.73, 2.88, 5.76 7.68) five diameter (0.181, 2.188, 4.42, 8.89 17.8 μm) considered. Constant flow proportional with inlet velocity cases examined comparatively. Results show that,...

Bacteria-carrying particles released by surgical staff are the main factors leading to site infections (SSI). Operating rooms must be designed reduce risks of such infections. In this numerical study, effect different ceiling heights on particle dispersion and deposition studied for an operating room with laminar airflow (LAF) system. Two diameters (12 20 ìm) tested under three (2.43–2.8–3.0 m) at a constant air change rate (ACH=20). Numerical predictions performed using commercial software...

In this study, particle decay in a cleanroom is investigated numerically. A commercial CFD package, FLUENT, used the analysis. The governing equations are solved by using k-å turbulence model. For dispersion, discrete phase model (DPM) applied. Four different air change rates (3-10-25-43 ACH) with three diameters (0,5-5-10 ìm) considered. It shown that 10 ACH satisfies needs terms of recovery time.

Poultry evisceration poses a risk of airborne carcass contamination with pathogens. While prior research has identified this hazard, ventilation strategies to mitigate it remain underexplored. This study employed computational fluid dynamics (CFD) simulations using Star-CCM+ software evaluate the efficacy local exhaust and mechanical barriers against contamination. Particle deposition under various scenarios was assessed. The demonstrated near-complete prevention both direct indirect...

Abstract Similarity between a model and prototype is important for scale experimental studies. Proper scaling by considering similarity parameters can lead to valuable results. The objective of this study investigate dispersion fine particles under different air change rates numerical techniques. Experimental studies are performed on 1:5 reduced model. considered kinematic particle similarities. RNG k – ε turbulence used in the predictions. It shown that average room outlet concentrations...

Abstract The air quality of enclosed spaces has attracted great attention due to the ongoing Covid-19 pandemic. infection risk in these can be estimated for various scenarios with different methods so important parameters and effective prevention measures compared. Previous studies showed that indoor CO 2 concentration could considered a surrogate risk. In this regard, generic relation established between levels probability. Based on consideration, some practical evaluations are conducted...

Abstract This study investigates the effect of exhaust outlet location on airflow and particle distribution in an operating room with laminar ventilation system via computational fluid dynamics (CFD). Four different opening locations three diameters (5, 10 20μm) are taken into consideration for same air change rate (30 ACH). It is found that total number particles deposited table decreased by 64 % smallest diameter (5 μm) 26 largest (20 when ceiling floor level outlets used together.

Bu çalışmada, hava değişim katsayının partikül dağılımına etkisi farklı kirletici kaynak konumları için deneysel ve sayısal olarak incelenmiştir. Deneysel çalışma küçük ölçekli bir model oda üzerinde izotermal akış şartları yürütülmüş 0,5 µm ebatında partiküller kullanılmıştır. Partikül hareketleri, Lagrange yaklaşımı esas alınarak hesaplamalı akışkanlar dinamiği (HAD) yazılımı olan ANSYS Fluent programında modellenmiştir. Ana bölgesi dışında yer alan kirleticilerin daha yüksek konsantrasyon...

In this study contaminant distribution in an operating room is evaluated experimentally to be able compare different ventilation concepts afterwards. Low-turbulent unidirectional (LAF) used study. Heated dummies are positioned around the table, which release tracer particles that surrogate airborne germs and measured critical areas for bacteria spread. Measurement results compared terms of degree protection as well local air quality index. It shown realistic arrangements limit usage...