Study on the Thermal Environment Inside a Fully-Enclosed Subway Noise Barrier

The thermal environment inside a fully-enclosed subway noise barrier shall be designed according to underground section tunnel standards. This article constructs a model using practical examples, simulates calculations on fully-enclosed noise barrier installations both with and without air vents via a threedimensional numerical simulation method, and then conducts a comparative analysis of the effects noise barrier lengths and air vent widths have on an internal thermal environment. The calculation results show that when the length of the fully-enclosed noise barrier without air vents was 100m, the internal thermal environment exceeded the limit; as the width of the air vents increased, the temperature in the internal environment gradually decreased, but the reduction was less once the air vent width exceeded 2 m; When the top air vent width was 2 m, and the noise barrier length was 100m, the thermal environment was found to meet requirements. As the noise barrier length increased, the internal air temperature exceeded the standards by varying degrees.

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Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

International Journal of Aerospace Engineering ◽

10.1155/2017/8695170 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Zhengzhi Wang ◽

Chunling Zhu

Keyword(s):

Numerical Simulation ◽

Centrifugal Force ◽

Rotor Blade ◽

Flow Direction ◽

Three Dimensional ◽

Simulation Method ◽

Two Phase ◽

Numerical Simulation Method ◽

Calculation Results ◽

Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

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DEVELOPMENT OF A NUMERICAL SIMULATION METHOD FOR PREDICTION AND EVALUATION OF THE THERMAL ENVIRONMENT IN THE DEVELOPED URBAN LOCATIONS WITH EVAPORATIVE VOID-BRICK WALLS

AIJ Journal of Technology and Design ◽

10.3130/aijt.15.179 ◽

2009 ◽

Vol 15 (29) ◽

pp. 179-182 ◽

Cited By ~ 1

Author(s):

Jiang HE ◽

Akira HOYANO ◽

Yasuyuki MACHIDA ◽

Kazuaki NAKAOHKUBO ◽

Tea-yum AUM

Keyword(s):

Numerical Simulation ◽

Thermal Environment ◽

Simulation Method ◽

Numerical Simulation Method

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Numerical simulation method to predict the thermal environment inside a car cabin

JSAE Review ◽

10.1016/s0389-4304(00)00101-6 ◽

2001 ◽

Vol 22 (1) ◽

pp. 39-47 ◽

Cited By ~ 14

Author(s):

A Fujita

Keyword(s):

Numerical Simulation ◽

Thermal Environment ◽

Simulation Method ◽

Numerical Simulation Method

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Some Effects on the Temperature of the Mine Air at the Heading Face

Inżynieria Mineralna ◽

10.29227/im-2021-02-39 ◽

2021 ◽

Vol 1 (2) ◽

Author(s):

Van Quang NGUYEN ◽

Van Thinh NGUYEN ◽

Cao Khai NGUYEN ◽

Van Chung PHAM

Keyword(s):

Numerical Simulation ◽

High Temperature ◽

Temperature Distribution ◽

Air Temperature ◽

Significant Influence ◽

Thermal Environment ◽

Simulation Method ◽

Forced Ventilation ◽

Ansys Cfx ◽

Ventilation Method

Currently, with the increase in mining output leading to deeper mining levels, the volume ofheading face serving production has also increased. The thermal environment tends to worsen whendigging deep due to the geothermal's effect, which increases the air temperature at the heading face.According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. Toensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amountof air to ensure a favorable environment for workers. With the forced ventilation method, the duct positionis usually arranged on the side, and the distance from the duct mouth to the heading face is determined toensure that l < 6√s. In this study, a numerical simulation method by Ansys CFX software is applied tostudy the influence of several factors such as duct position, air temperature of duct, and roughnesscharacteristics of roadway on the temperature of the mine air at the heading face. The models are set upwith six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better thanmodels 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models havedifferent wind temperatures, and we can see the significant influence of the inlet air temperature of theduct on the thermal environment of the heading face. The results show that with the model T = 297.15K,the temperature value on the roadway length is guaranteed as specified < 303K. The result is a referencefor determining the duct position and cool for the high-temperature heading face.

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Study on Critical Anchorage Length of Bolts by Numerical Simulation Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.4771 ◽

2012 ◽

Vol 204-208 ◽

pp. 4771-4775

Author(s):

Bo Wang ◽

Jian Nan Zhou ◽

Feng Nian Jin ◽

Mei Rong Jiang

Keyword(s):

Numerical Simulation ◽

Comparative Analysis ◽

Frictional Resistance ◽

Simulation Method ◽

Calculation Model ◽

Measured Data ◽

Anchorage Length ◽

Numerical Simulation Method

Numerical simulation method was used to study the problems on critical anchorage length of bolts. 3-D calculation model was built by FLAC program. By numerical simulation calculations, the conclusion could be drawn: the frictional resistance contribution had nothing to do with drawing forces, and was relevant to the bond stiffness of anchor mortar. And comparative analysis results of one engineering example showed that the calculated values by the presented method agreed well with the measured data.

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