scholarly journals Influence of grass lawns on the summer thermal environment and microclimate of heritage sites: a case study of Fuling mausoleum, China

2021 ◽  
Vol 9 (1) ◽  
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

AbstractThe 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. Simulations with the lawns, the bricked ground temperature decreased by 1.56–17.54 °C than that simulations without the lawns 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 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 RS and GIS Supported Urban LULC and UHI Change Simulation and Assessment

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Pei Liu ◽  
Shoujun Jia ◽  
Ruimei Han ◽  
Yuanping Liu ◽  
Xiaofeng Lu ◽  
...  
Keyword(s):  
Land Surface ◽  
Thermal Environment ◽  
Urban Expansion ◽  
Dynamic Change ◽  
Urban Sustainability ◽  
Remotely Sensed Data ◽  
Rapid Urbanization ◽  
Urban Heat ◽  
High Level ◽  
The Impact

Rapid urbanization has become a major urban sustainability concern due to environmental impacts, such as the development of urban heat island (UHI) and the reduction of urban security states. To date, most research on urban sustainability development has focused on dynamic change monitoring or UHI state characterization, while there is little literature on UHI change analysis. In addition, there has been little research on the impact of land use and land cover changes (LULCCs) on UHI, especially simulates future trends of LULCCs, UHI change, and dynamic relationship of LULCCs and UHI. The purpose of this research is to design a remote sensing-based framework that investigates and analyzes how the LULCCs in the process of urbanization affected thermal environment. In order to assess and predict the impact of LULCCs on urban heat environment, multitemporal remotely sensed data from 1986 to 2016 were selected as source data, and Geographic Information System (GIS) methods such as the CA-Markov model were employed to construct the proposed framework. The results showed that (1) there has been a substantial strength of urban expansion during the 40-year study period, (2) the farthest distance urban center of gravity moves from north-northeast (NEE) to west-southwest (WSW) direction, (3) the dominate temperature was middle level, sub-high level, and high level in the research area, (4) there was a higher changing frequency and range from east to west, and (5) there was a significant negative correlation between land surface temperature and vegetation and significant positive correlation between temperature and human settlement.

Land-Use/Land-Cover Changes and Their Influence on Urban Thermal Environment in Zhengzhou City During the Period of 1986 to 2026

2020 ◽  
Author(s):  
Pei Liu ◽  
Ruimei Han ◽  
Leiku Yang
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Thermal Environment ◽  
Dynamic Change ◽  
Urban Sustainability ◽  
Land Cover Changes ◽  
Rapid Urbanization ◽  
Urban Heat ◽  
High Level ◽  
The Impact

<p>Rapid urbanization has become a major urban sustainability concern due to environmental impacts, such as development of urban heat island (UHI) and the reduction of urban security states. To date, most research on urban sustainability development has focus on dynamic change monitoring or UHI state characterization. While there is little literature on UHI change analysis. In addition, there has been little research on the impact of land use and land cover changes (LULCCs) on UHI, especially simulates future trend of LULCCs, UHI change, and dynamic relationship of LULCCs and UHI. The purpose of this research is to design a remote sensing based framework that investigates and analysis that how the LULCCs in the process of urbanization affected thermal environment. In order to assesses and predicts impact of LULCCs on urban heat environment, multi-temporal remotely sensed data from 1986 to 2016 were selected as source data, and Geographic Information System (GIS) methods such as CA-Markov model were employed to construct the proposed framework. The results shown that (1) there has been a substantial strength of urban expansion during the 40 years study period; (2) the most far distance urban center of gravity movement from north-northeast (NEE) to west-southwest (WSW) direction; (3) the dominate temperature were middle level, sub-high level and high level in the research area; (4) there was a higher changing frequency and range from east to west; (5) there was significant negative correlation between land surface temperature and vegetation, and significant positive correlation between temperature and human settlement.</p>

Optimization Monitoring Points of Urban Road Traffic Noise in Binzhou City

2014 ◽  
Vol 1073-1076 ◽  
pp. 522-525
Author(s):  
Fu Guo Zhao
Keyword(s):  
Noise Level ◽  
Road Traffic ◽  
Traffic Noise ◽  
Measurement Data ◽  
Experimental Results ◽  
Road Traffic Noise ◽  
Actual Measurement ◽  
Urban Road ◽  
The Impact

Considering the Impact of the current urban road traffic noise,I optimize the traffic noise monitoring points on the basis of the actual measurement data. The experimental results prove that less monitoring points may reflect the overall traffic noise level in Binzhou City.

The Application of BIM in Updating the Thermal Environment Design of Traditional Residences in Mountain Region - A Case of Chongqing

2013 ◽  
Vol 779-780 ◽  
pp. 1324-1327
Author(s):  
Jing Yang Wang ◽  
Xin Sun ◽  
Xu Dong Zeng
Keyword(s):  
Quantitative Analysis ◽  
Wind Speed ◽  
Ambient Temperature ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Wind Pressure ◽  
Cultural Value ◽  
Environment Design ◽  
Rapid Urbanization ◽  
Indoor Comfort

As an important type of folk houses with the historical and cultural value in China, the mountainous residence is occupying an important historical position in the rapid urbanization. Whereas, traditional dwellings in Chongqing are in an "overload" condition and poorly indoor comfort. With the help of BIM technology, we can simulation analysis of the ambient temperature, the age of air, wind speed and wind pressure, soughting to a method of quantitative analysis of mountain traditional houses, and the design of ecological energy-saving.

scholarly journals Characterization of the Solid Particle Erosion of the Sealing Surface Materials of a Ball Valve

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Donghua Peng ◽  
Shaohua Dong ◽  
Zhiqiang Wang ◽  
Dongying Wang ◽  
Yinuo Chen ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Simulation Analysis ◽  
Impact Angle ◽  
Ball Valve ◽  
Phase Flow ◽  
Two Phase ◽  
Valve Sealing ◽  
The Impact

The ball valve is an essential piece of equipment in an oil and gas pipeline. The sand particles transported through the pipeline can cause erosion and wear to the ball valve, thus causing it to fail, leading to serious safety hazards. In this paper, the self-designed erosion experiment method was combined with computational fluid dynamics (CFD), while the Euler-Lagrange method was also introduced to optimize the Oka erosion model and Ford particle-wall rebound model. The erosion mechanism and characteristics of the ball valve sealing surface in gas-solid two-phase flow were simulated, while the erosion condition of the specimen was analyzed and compared when exposed to different factors, such as different particle velocities, impact angle, particle size, and specimen materials. The experimental data conformed well to the CFD erosion simulation data, verifying the accuracy of the CFD simulation analysis. The results indicated that the worn surface was caused by various wear mechanisms, while a “stagnation zone” was identified at the center of the specimen. The maximum erosion area, which was U-shaped, was also located at the center. The erosion rate increased in conjunction with an increase in the particle velocity and size, both of which failed to affect the erosion pattern. The erosion rate initially increased, after which it decreased with the impact angle, reaching the maximum value at an impact angle of 30°. This paper summarizes the erosion failure mechanism and characteristics in gas–solid two-phase flow and provides both technical support and a theoretical basis for the on-site maintenance of essential vulnerable parts in the pipeline, such as ball valves.

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.

A TOPSIS optimization for the indoor thermal environment through oscillating airflow generated from a cassette split type air conditioner

2020 ◽  
pp. 1420326X2093930
Author(s):  
Yunqing Fan
Keyword(s):  
Thermal Performance ◽  
Cfd Simulation ◽  
Control Method ◽  
Thermal Environment ◽  
Vertical Section ◽  
Thermal Preference ◽  
Air Conditioner ◽  
Indoor Thermal Environment ◽  
Swing Angle ◽  
The Impact

This study evaluates the feasibility of a control method, ‘the Technique for Order of Preference by Similarity to Ideal Solution’ (TOPSIS) for the optimization of the subzone thermal environment by optimizing the oscillating airflow generated from a cassette split type air conditioner. To address the quasi-dynamic thermal comfort problems, various operation swinging angles of the louvre in the supply opening of an air conditioner and swinging periods were investigated by computational fluid dynamics (CFD) simulation. The impact of air supply control strategies (louvres movement) on the indoor thermal environment was evaluated by multi-criteria operation under quasi-dynamic conditions. The operation parameters were shown to have significantly improved the deviation in thermal uniformity by 16.5% and thermal preference by 7.6%. A 40 s swing period and wider swing angles for the operation of the inner louvre would satisfy the thermal uniformity rather than other alternatives. A shorter swing period <20 s is insufficient to allow perfect airflow mixing at the vertical section. For individual target mode such as the room corner, the thermal performance is more sensitive to the swing angle than the swing period; by increasing the swing angle to ±60° to enhance thermal preference, a 24.1% increase in the overall thermal performance would be achieved.

scholarly journals Regional-scale geostatistical inverse modeling of North American CO<sub>2</sub> fluxes: a synthetic data study

2010 ◽  
Vol 10 (13) ◽  
pp. 6151-6167 ◽  
Author(s):  
S. M. Gourdji ◽  
A. I. Hirsch ◽  
K. L. Mueller ◽  
V. Yadav ◽  
A. E. Andrews ◽  
...  
Keyword(s):  
North America ◽  
Flux Distribution ◽  
Regional Scale ◽  
Measurement Data ◽  
Synthetic Data ◽  
Surface Fluxes ◽  
Co2 Fluxes ◽  
Actual Measurement ◽  
Diurnal Variability ◽  
The Impact

Abstract. A series of synthetic data experiments is performed to investigate the ability of a regional atmospheric inversion to estimate grid-scale CO2 fluxes during the growing season over North America. The inversions are performed within a geostatistical framework without the use of any prior flux estimates or auxiliary variables, in order to focus on the atmospheric constraint provided by the nine towers collecting continuous, calibrated CO2 measurements in 2004. Using synthetic measurements and their associated concentration footprints, flux and model-data mismatch covariance parameters are first optimized, and then fluxes and their uncertainties are estimated at three different temporal resolutions. These temporal resolutions, which include a four-day average, a four-day-average diurnal cycle with 3-hourly increments, and 3-hourly fluxes, are chosen to help assess the impact of temporal aggregation errors on the estimated fluxes and covariance parameters. Estimating fluxes at a temporal resolution that can adjust the diurnal variability is found to be critical both for recovering covariance parameters directly from the atmospheric data, and for inferring accurate ecoregion-scale fluxes. Accounting for both spatial and temporal a priori covariance in the flux distribution is also found to be necessary for recovering accurate a posteriori uncertainty bounds on the estimated fluxes. Overall, the results suggest that even a fairly sparse network of 9 towers collecting continuous CO2 measurements across the continent, used with no auxiliary information or prior estimates of the flux distribution in time or space, can be used to infer relatively accurate monthly ecoregion scale CO2 surface fluxes over North America within estimated uncertainty bounds. Simulated random transport error is shown to decrease the quality of flux estimates in under-constrained areas at the ecoregion scale, although the uncertainty bounds remain realistic. While these synthetic data inversions do not consider all potential issues associated with using actual measurement data, e.g. systematic transport errors or problems with the boundary conditions, they help to highlight the impact of inversion setup choices, and help to provide a baseline set of CO2 fluxes for comparison with estimates from future real-data inversions.

scholarly journals A Study Regarding the Thermal Environment and Thermal Comfort during the 2021 National Intercollegiate Athletic Games and Related Activities in Taiwan

2021 ◽  
Vol 8 (1) ◽  
pp. 32
Author(s):  
Si-Yu Yu ◽  
Andreas Matzarakis ◽  
Tzu-Ping Lin
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Extreme Weather Events ◽  
Intercollegiate Athletic ◽  
Outdoor Sports ◽  
Human Thermal Comfort ◽  
Knowledge Platform ◽  
Globe Temperature ◽  
Radiant Temperature ◽  
The Impact

Due to the impact of global warming and extreme weather events, outdoor human thermal comfort conditions become tougher and harder to mitigate, especially for pedestrian movement and exercises. In order to better understand the thermal environment and thermal comfort, especially for outdoor sports, the 2021 National Intercollegiate Athletic Games held in Tainan, southern Taiwan, in May was selected as the research target. Both on-site, real-time environmental monitoring data and the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP)’s Taiwan ReAnalysis Downscaling data (TReAD) were applied to estimate the modified physiologically equivalent temperature (mPET), the mean radiant temperature (Tmrt), and the wet bulb globe temperature (WBGT) for members participating in the relevant activities. The focus of this study was to analyze the thermal performance of (1) the torch relay around Taiwan from 20 April to 8 May and (2) the scheduled planning games held at the track and field stadium, at the National Cheng Kung University (NCKU), Taiwan, from May 15 to May 18, 2021.

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