scholarly journals Investigation of Check Valve Aerodynamic Characteristics in Different Operating Modes

2018 ◽  
Vol 3 (3) ◽  
pp. 127
Author(s):  
D.A. Pakholik ◽  
A.V. Sobolev ◽  
A.S. Shelegov

The paper presents a computational study of the NPP ventilation system check valve aerodynamics, namely, a numerical simulation of the air flowing through the open valve with the subsequent determination of the relationship between the reactive torque acting on the valve closure axles and the input air velocity.This numerical simulation of the air flowing through the check valve was performed using the ANSYS CFX program. In the computation, different operating modes of the check valve were considered when the air flow was passing through it. The valve operating modes were set depending on changes in the input air velocity. As a result of aerodynamic computation, the values of pressure and velocity components were obtained over the entire valve volume.Reactive forces were calculated in the ANSYS Mechanical program. The reactive forces acting on the valve body form a torque at the gate axles. When adjusting the check valve to the actual flow rate, it is necessary to know this torque value and compensate for it. As a result of a series of computations of reactive forces, a relationship was found between the torque value of the valve’s working element axles and the input air velocity. 

2009 ◽  
Vol 13 (1) ◽  
pp. 69-78
Author(s):  
Milos Banjac ◽  
Barbara Nikolic

With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.


2014 ◽  
Vol 1079-1080 ◽  
pp. 574-578
Author(s):  
Zhen Jie Hu ◽  
Xiao Fan Song

Using CFD software to simulate the indoor different ventilation system of different outlet position. Analysis the characteristics of the interior velocity field and temperature field in different conditions.We obtain in the same conditions ,set air vent on the home have a bigger efficiency than the traditional way.,and supply air velocity has a remarkable influence on the ventilation efficiency compared to the supply air temperature.


2007 ◽  
Vol 14 (2) ◽  
pp. 201-223
Author(s):  
Chin-Lung Chang ◽  
Chang-Hsien Tai ◽  
Chien-Hsiung Tsai ◽  
Yu-Ren Wang ◽  
Qing-Shan Hon

2019 ◽  
Vol 128 ◽  
pp. 10002
Author(s):  
Angel Huminic ◽  
Gabriela Huminic

This paper presents new results concerning the aerodynamics of the Ahmed body fitted with a non-flat underbody diffuser. As in previous investigations performed, the angle and the length of the diffuser are the parameters systematically varied within ranges relevant for a hatchback passenger car. Coefficients of lift and drag are compared with the values obtained for the flat underbody diffuser, and the results reveal significant improvements concerning aerodynamic characteristics of body.


2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song

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.


2005 ◽  
Vol 29 (2) ◽  
pp. 89-113 ◽  
Author(s):  
Niels Troldborg

A comprehensive computational study, in both steady and unsteady flow conditions, has been carried out to investigate the aerodynamic characteristics of the Risø-B1-18 airfoil equipped with variable trailing edge geometry as produced by a hinged flap. The function of such flaps should be to decrease fatigue-inducing oscillations on the blades. The computations were conducted using a 2D incompressible RANS solver with a k-w turbulence model under the assumption of a fully developed turbulent flow. The investigations were conducted at a Reynolds number of Re = 1.6 · 106. Calculations conducted on the baseline airfoil showed excellent agreement with measurements on the same airfoil with the same specified conditions. Furthermore, a more widespread comparison with an advanced potential theory code is presented. The influence of various key parameters, such as flap shape, flap size and oscillating frequencies, was investigated so that an optimum design can be suggested for application with wind turbine blades. It is concluded that a moderately curved flap with flap chord to airfoil curve ratio between 0.05 and 0.10 would be an optimum choice.


2012 ◽  
Vol 30 (1) ◽  
pp. 1-12 ◽  
Author(s):  
J. M. P. Q. Delgado ◽  
A. S. Guimarães ◽  
V. P. de Freitas

2021 ◽  
Vol 3 (1) ◽  
pp. 049-053
Author(s):  
M. A. KRIVOSHEIN ◽  
◽  
K. D. SMIRNOV ◽  
K. V. MESHKO ◽  
◽  
...  

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


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