scholarly journals Modelling of air flow supply in a room at variable regime by using both K - E and spalart – allmaras turbulent model

2017 ◽  
Vol 12 (2) ◽  
pp. 15-22
Author(s):  
Vadim Korbut ◽  
Orest Voznyak ◽  
Iryna Sukholova ◽  
Khrystyna Myroniuk
Keyword(s):  
Air Flow ◽  
Ventilation System ◽  
Air Distribution ◽  
Experimental Investigations ◽  
Human Organism ◽  
Ansys Fluent ◽  
Air Jets ◽  
Air Supply ◽  
Experimental Researches ◽  
Variable Regime

Abstract The abstract is to The article is devoted to the decision of actual task of air distribution efficiency increasing with the help of swirl and spread air jets to provide normative parameters of air in the production apartments. The mathematical model of air supply with swirl and spread air jets in that type of apartments is improved. It is shown that for reachin of air distribution maximal efficiency it is necessary to supply air by air jets, that intensively extinct before entering into a working area. Simulation of air flow performed with the help of CFD FLUENT (Ansys FLUENT). Сalculations of the equation by using one-parameter model of turbulence Spalart-Allmaras are presented. The graphical and the analytical dependences on the basis of the conducted experimental researches, which can be used in subsequent engineering calculations, are shown out. Dynamic parameters of air flow that is created due to swirl and spread air jets at their leakage at variable regime and creation of dynamic microclimate in a room has been determined. Results of experimental investigations of air supply into the room by air distribution device which creates swirl air jets for creation more intensive turbulization air flow in the room are presented. Obtained results of these investigations give possibility to realize engineer calculations of air distribution with swirl air jets. The results of theoretical researches of favourable influence of dynamic microclimate to the man are presented. When using dynamic microclimate, it’s possible to decrease conditioning and ventilation system expenses. Human organism reacts favourably on short lasting deviations from the rationed parameters of air environment.

scholarly journals Modeling of air flow in industrial rooms

2018 ◽  
Vol 13 (1) ◽  
pp. 21-28
Author(s):  
Yuriy Yurkevych ◽  
Iryna Sukholova ◽  
Mariana Kasynets
Keyword(s):  
Air Flow ◽  
Air Distribution ◽  
Experimental Investigations ◽  
Human Organism ◽  
Dynamic Parameters ◽  
Ansys Fluent ◽  
Air Jets ◽  
Air Supply ◽  
The Mathematical Model ◽  
Variable Regime

Abstract The article is devoted to the air distribution in a room by swirl and laying air jets. Dynamic parameters of air flow that is created due to swirl and laying air jets at their leakage in a room has been determined. The mathematical model of air supply with swirl and laying air jets in the industrial rooms is improved. Simulation of air flow is performed due to CFD FLUENT (Ansys FLUENT). Solution of the equation by using k-ε model of turbulence is presented. Dynamic parameters of air flow that is created due to swirl and laying air jets at their leakage at variable regime and creation of dynamic microclimate in a room has been determined. Results of experimental investigations of air supply into the room by air distribution device which creates swirl air jets for creation more intensive turbulence air flow in the room are presented. The results of theoretical researches of influence of dynamic microclimate to the human organism are presented.

scholarly journals The Characteristics of Air Swirl Supply Device

2012 ◽  
Vol 7 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Orest Voznyak ◽  
Iryna Sukholova ◽  
Khrystyna Myroniuk
Keyword(s):  
Air Flow ◽  
Air Distribution ◽  
Experimental Investigations ◽  
Air Jets ◽  
Air Supply ◽  
Three Factor

Abstract In this article results of experimental investigations of air supply into the room by air distribution device which creates swirl air jets for creation more intensive turbulization air flow in the room are presented. Experimental investigations in order to composed matrix were carried out; graphycal dependences have been obtained as well three-factor chart has been designed. Obtained results of these investigations give possibility to realize engineer calculations of air distribution with swirl air jets.

scholarly journals Use of Air Infiltration in Swine Housing Ventilation System Design

2019 ◽  
Vol 35 (3) ◽  
pp. 325-338
Author(s):  
H T Jadhav ◽  
S J Hoff
Keyword(s):  
Ventilation System ◽  
Three Dimensional ◽  
Design Procedure ◽  
Field Testing ◽  
Air Distribution ◽  
Air Jets ◽  
Air Infiltration ◽  
Air Jet ◽  
Archimedes Number ◽  
Ventilation Systems

Abstract.The objective of this research was to develop and analyze the procedure for using recent air infiltration (AI) data collected from commercial swine finishing rooms (SFRs) in the design of negative pressure mechanical ventilation systems (VSs). Air infiltration is an integral part of any ventilation process. Infiltration reduces the pressure differential across planned inlets and at very low pressure differences, cold air jets may drop directly on the animals causing significant discomfort. In this article, a design procedure is proposed for swine housing ventilation systems with the influence of air infiltration included. The method was used on one SFR for which air infiltration data was collected by in-field testing. The air-jet throw, jet momentum number, a newly developed coverage factor, and Archimedes number were used to assess the influence of infiltration on predicted air-jet and fresh-air distribution and to help guide the design of planned inlets in SFR VSs with known infiltration. The analysis completed quantifies the severity of AI on air-jet and air distribution performance, and suggests that for the analysis room to ventilate properly requires a 50% reduction in AI levels beyond field measured curtain and fan infiltration. The analysis completed suggests a method for systematically planning three-dimensional ceiling inlet placement and operation and provides design guidance for new ceiling inlets suitable for SFR VSs. Keywords: Air distribution, Air-jets, Archimedes number, Infiltration, Jet Momentum Number.

scholarly journals An Air Terminal Device with a Changing Geometry to Improve Indoor Air Quality for VAV Ventilation Systems

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4947
Author(s):  
Nina Szczepanik-Scislo ◽  
Jacek Schnotale
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Ansys Fluent ◽  
Variable Air Volume ◽  
Terminal Device ◽  
Air Volume ◽  
Air Supply ◽  
Volume Ventilation ◽  
Ventilation Efficiency ◽  
Comfort Parameters

This study aimed to develop a new concept for an air terminal device for a VAV (variable air volume) ventilation system that would improve overall ventilation efficiency under a varying air supply volume. In VAV systems, air volume is modified according to the thermal load in each ventilated zone. However, lowering the airflow may cause a lack of proper air distribution and lead to the degradation of hygienic conditions. To combat this phenomenon, an air terminal device with an adapting geometry to stabilize the air throw, such that it remains constant despite the changing air volume supplied through the ventilation system, was designed and studied. Simulations that were performed using the RNG k–ε model in the ANSYS Fluent application were later validated on a laboratory stand. The results of the study show that, when using the newly proposed terminal device with an adaptive geometry, it is possible to stabilize the air throw. The thermal comfort parameters such as the PMV (predicted mean vote) and PPD (predicted percentage of dissatisfied) proved that thermal comfort was maintained in a person-occupied area regardless of changing airflow though the ventilation system.

scholarly journals Method of the boiler room ventilation system efficiency experimental determination

2020 ◽  
Vol 2020 (2) ◽  
pp. 84-91
Author(s):  
Orest Voznyak ◽  
◽  
Yuriy Yurkevych ◽  
Iryna Sukholova ◽  
Oleksandr Dovbush ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Average Velocity ◽  
Air Flow ◽  
Ventilation System ◽  
Experimental Studies ◽  
Air Velocity ◽  
Air Jets ◽  
Boiler Room ◽  
Air Exchange

The issue of the normative air exchange ensuring in the premises of the boiler houses is extremely important. The article presents the results of theoretical and experimental studies of air velocity determination in the distribution of air by round and compact jets in the boiler room. Graphical and analytical dependences are given. The research results substantiate the higher accuracy of the average air flow velocity determination in small boiler rooms. The aim of the work is to develop a method for experimental determination of the efficiency of the ventilation system in the boiler room; to increase of the accuracy of the average velocity determination of the round and the compact air jets in the plane of the supply nozzle to ensure the normative air exchange of the boiler room and to substantiate of the calculation method. The characteristics and patterns of development of round and compact air jets in the premises are established and the calculated dependences are obtained. The unitless integral air velocity for the round and compact air jets in the boiler room is established. Calculation dependences for determining of the air flow rate in the boiler room have been obtained. It is substantiated that the application of the proposed method will significantly increase the accuracy of air exchange determination in the boiler rooms to ensure the required value in accordance with regulatory requirements. Also it is substantiated that to obtain satisfactory experimental results on speed measurements in the boiler room, it is necessary to measure the speed in the center of the supply nozzle several times with maximum accuracy. Then multiply the result by the relative average velocity: for a round jet vav = 0,26 and for a compact jet – vav = 0,2025. The obtained results allow to avoid a significant error (19 %) in determining the required air exchange ventilation of the boiler room. Recommendations for the practical determination of the calculated values to ensure proper ventilation of the boiler rooms are given.

scholarly journals On-site measurement and numerical investigation of thermal environment with different air distribution systems in ice arenas

2021 ◽  
Vol 2069 (1) ◽  
pp. 012096
Author(s):  
Wenyu Lin ◽  
Tao Zhang ◽  
Xiaohua Liu ◽  
Lingshan Li
Keyword(s):  
Thermal Environment ◽  
Ventilation System ◽  
Simulation Method ◽  
Extreme Condition ◽  
Air Distribution ◽  
Jet Ventilation ◽  
Displacement Ventilation ◽  
Air Supply ◽  
Temperature And Humidity ◽  
Ice Field

Abstract It is important to strictly maintain the indoor thermal environment in ice arenas which have very different features to other commercial buildings. Separated air distribution system is widely used to create a dry and cold environment near the ice and a comfortable environment in the view stand. The warm and humid air from the view stand may lead to uneven temperature and humidity distribution in the rink, leading to extra energy consumption, even fog and frost on the ice. Unreasonable air supply in the ice rink zone will also make the spectators feel too cold and uncomfortable. Jet ventilation system is the most extensively used system in the ice rink zone. An innovative ground displacement ventilation system is proposed in the National Aquatics Centre, which will serve as the venue for the curling competition in the 2022 Beijing Winter Olympics. On-site measurement in the arena is carried out and computational fluid dynamics (CFD) simulation method is adopted in the present research. Measured thermal environment above the ice with different ventilation systems are compared and analysed. Result shows that the displacement ventilation system features a more obvious vertical stratification than jet ventilation system in this kind of large space buildings, and thus is more energy-efficient. A CFD model of the ice cube is setup and verified by measured data. The thermal environment in the ice rink with displacement ventilation under extreme condition is studied using the simulation method. The temperature and humidity in the ice field increases by 10.1 °C, 4.5 g/kg without air supply in the view stand, proving that the spectators in the view stand have a great impact on the thermal environment in the ice field.

scholarly journals Enhancing of energetic and economic efficiency of air distribution by swirled-compact air jets

2021 ◽  
Vol 27 (3) ◽  
pp. 171-175
Author(s):  
Vasyl Zhelykh ◽  
Orest Voznyak ◽  
Yuriy Yurkevych ◽  
Iryna Sukholova ◽  
Oleksandr Dovbush
Keyword(s):  
Indoor Air ◽  
Ventilation System ◽  
Air Distribution ◽  
Energy Audit ◽  
Indoor Climate ◽  
Air Jets ◽  
Air Jet ◽  
Urgent Task ◽  
Exhaust Heat ◽  
System Reconstruction

Abstract The article is devoted to solving the urgent task of increasing the efficiency of air distribution by swirled-compact air jets to ensure the normative parameters of indoor air. The dynamic parameters of the swirled-compact air jet during its leakage in the alternating mode and the formation of a dynamic indoor climate in the room are determined. For improvement of comfortable conditions in the room and design of energy saving circuits of air distribution it is suggested to use swirled-compact air jets, which flow from the inflow and exhaust heat recuperators with heat recovery of the exhaust air. An energy audit of the ventilation system reconstruction with a recuperator using was carried out. The method of taking into account the fact of application of several measures, which cannot be carried out simultaneously, and discount rate dynamics is proposed.

Optimization Design Study on Uniform Air of Structure of the Cavity Plenum of Badminton Gymnasium

2014 ◽  
Vol 548-549 ◽  
pp. 1635-1640
Author(s):  
Zhan Liang Zu ◽  
Chao Chen ◽  
Le Yan ◽  
Na Li
Keyword(s):  
Optimization Design ◽  
Ventilation System ◽  
Air Distribution ◽  
Design Requirement ◽  
Original Design ◽  
Playing Field ◽  
Air Supply ◽  
University Of Technology ◽  
Computational Fluid Dynamics Cfd ◽  
Playing Fields

The badminton gymnasium of Beijing University of Technology is the main built gymnasium for Olympic Games in 2008 in Beijing. Based on the design requirement, the velocity in the playing-field should be less than 0.2m/s in the region of 9m above the playing-fields ground. To guarantee the design requirement, this paper uses the methods of Computational Fluid Dynamics (CFD) technology and field test to optimize and modify the original design of the cavity’s structure. After optimization and modification, plenum makes obvious sense on air distribution of structure of the cavity, which guarantees the 9100 swirl diffusers uniform air supply under the grandstand seats, the velocity in the playing-field is less than 0.2m/s, which meets the design requirement. The results can be referred to optimization design of air-conditioning ventilation system in large badminton gymnasiums.

A Computational Analysis of Flow Field in Twin-Track Subway Tunnel to Improve Air Quality

2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song
Keyword(s):  
Air Quality ◽  
Computational Model ◽  
Stokes Equations ◽  
Ventilation System ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Subway Tunnel ◽  
Air Supply ◽  
And Performance

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.

scholarly journals Numerical Modelling Of Humid Air Flow Around A Porous Body

2015 ◽  
Vol 9 (3) ◽  
pp. 161-166
Author(s):  
Aneta Bohojło-Wiśniewska
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Porous Medium ◽  
Numerical Modelling ◽  
Chinese Cabbage ◽  
Air Flow ◽  
Transfer Model ◽  
Humid Air ◽  
Ansys Fluent ◽  
Complex Heat Transfer

Summary This paper presents an example of humid air flow around a single head of Chinese cabbage under conditions of complex heat transfer. This kind of numerical simulation allows us to create a heat and humidity transfer model between the Chinese cabbage and the flowing humid air. The calculations utilize the heat transfer model in porous medium, which includes the temperature difference between the solid (vegetable tissue) and fluid (air) phases of the porous medium. Modelling and calculations were performed in ANSYS Fluent 14.5 software.

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