Investigation on the Thermal Condition of a Traditional Cold-Lane in Summer in Subtropical Humid Climate Region of China

A Chinese traditional narrow street, named Cold-Lane, can create a microclimatic zone that provides pedestrian thermal comfort under hot and humid climate conditions. This phenomenon was observed through experimental measurement during the summer of 2016. The heat transfer rate over the pedestrian body surface was calculated to reveal why pedestrians experience a cool sensation, and computational flow dynamics (CFD) simulation was carried out to study the influence of the street aspect ratio on the shading effect. It was found that the perception of thermal comfort can be attributed mainly to the radiation between the relatively cool surrounding walls and the human body, and the wind velocity has little effect on sensible heat dissipation. The cool horizontal and vertical surfaces in the street canyon are mainly due to the shading effect as a result of the small aspect ratio, which is a typical characteristic of the traditional Chinese street. The shading effect of the high walls on both sides creates the cooling effect of this narrow street.

Download Full-text

An Investigation of Design Considerations to Achieve Thermal Comfort in Warm Humid Climatic Zone of West Bengal

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.39098 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1912-1917

Author(s):

Pritam Roy

Keyword(s):

Thermal Comfort ◽

Building Materials ◽

West Bengal ◽

Building Design ◽

Climatic Zone ◽

Primary Study ◽

Humid Climate ◽

Climate Conditions ◽

Building Orientation ◽

Design Factors

Abstract: This research paper presents the investigation of design consideration to achieve thermal comfort and the warm humid climatic zone of West Bengal is considered as the primary study area for the investigation. The varying thermal comfort behavior of humans in different climate conditions and seasons clearly demonstrates that the building design strategy must conform with the region of the building. In this paper, first studying the climatic characteristics of the warm humid region design factors are selected like building materials, cross ventilation, building orientation, roofing orientation, and materials, etc. After that, all those design factors are studied and the effect of all those factors on building in various conditions is observed. Keywords: Warm Humid Climate, Thermal Comfort, Building Materials, U-value, Cross Ventilation, Building Orientation

Download Full-text

Effects of Landscape Design on Urban Microclimate and Thermal Comfort in Tropical Climate

Advances in Meteorology ◽

10.1155/2018/2809649 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

Wei Yang ◽

Yaolin Lin ◽

Chun-Qing Li

Keyword(s):

Heat Stress ◽

Thermal Comfort ◽

Real Data ◽

Landscape Design ◽

Water Bodies ◽

Humid Climate ◽

Urban Microclimate ◽

Climate Conditions ◽

Design Elements ◽

Pavement Materials

A climate-responsive landscape design can create a more livable urban microclimate with adequate human comfortability. This paper aims to quantitatively investigate the effects of landscape design elements of pavement materials, greenery, and water bodies on urban microclimate and thermal comfort in a high-rise residential area in the tropic climate of Singapore. A comprehensive field measurement is undertaken to obtain real data on microclimate parameters for calibration of the microclimate-modeling software ENVI-met 4.0. With the calibrated ENVI-met, seven urban landscape scenarios are simulated and their effects on thermal comfort as measured by physiologically equivalent temperature (PET) are evaluated. It is found that the maximum improvement of PET reduction with suggested landscape designs is about 12°C, and high-albedo pavement materials and water bodies are not effective in reducing heat stress in hot and humid climate conditions. The combination of shade trees over grass is the most effective landscape strategy for cooling the microclimate. The findings from the paper can equip urban designers with knowledge and techniques to mitigate urban heat stress.

Download Full-text

Study on Environment Regulation of Residential in Severe Cold Area of China in Winter: Base on Outdoor Thermal Comfort of the Elderly

Sustainability ◽

10.3390/su11226509 ◽

2019 ◽

Vol 11 (22) ◽

pp. 6509

Author(s):

Hong Jin ◽

Bo Wang ◽

Bingbing Han

Keyword(s):

Thermal Comfort ◽

Cfd Simulation ◽

The Elderly ◽

Outdoor Thermal Comfort ◽

Residential Areas ◽

Physiological Equivalent Temperature ◽

Climate Conditions ◽

Outdoor Environments ◽

Harsh Climate ◽

Pet Index

Overwhelming evidence shows that the harsh climate conditions are affecting urban residents who are living in severe cold areas of China in winter, particularly affecting the frequency and length of outdoor space usage of the elderly. This study aims (1) to establish the modified model which is suitable for the harsh climate region, (2) to verify whether the physiological equivalent temperature (PET) index can be evaluated for the outdoor thermal comfort of older adults in severe cold areas of China in winter, (3) to draw the thermal comfort map that is based on the former conclusions. In this study, the outdoor environments in typical residential areas for the elderly of Changchun, China, has been investigated by using field measurement, questionnaire survey, and Computational Fluid Dynamics (CFD) simulation. The results show that the wind direction is the important aspects of model modification and quite possibly one of the most neglected. In addition, it is convenient to evaluate outdoor thermal comfort of the elderly on the basis of the PET index and the neutral PET temperature of elderly people who live in severe cold areas of China in winter is −0.5 degrees Celsius. According to the thermal comfort map, the park green land of urban residential is the best area for the elderly.

Download Full-text

Modification of MnS inclusion by tellurium in 38MnVS6 micro-alloyed steel

Metallurgical Research & Technology ◽

10.1051/metal/2020066 ◽

2020 ◽

Vol 117 (6) ◽

pp. 615

Author(s):

Ping Shen ◽

Lei Zhou ◽

Qiankun Yang ◽

Zhiqi Zeng ◽

Kenan Ai ◽

...

Keyword(s):

Fatigue Life ◽

Aspect Ratio ◽

Strong Influence ◽

Experimental Results ◽

Alloyed Steel ◽

Equivalent Diameter ◽

Small Aspect Ratio ◽

Steel Quality ◽

Eds Analysis ◽

Micro Alloyed Steel

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.

Download Full-text

A Toroidal mhd Equilibrium with a Small Aspect Ratio

Kakuyūgō kenkyū ◽

10.1585/jspf1958.22.99 ◽

1969 ◽

Vol 22 (2) ◽

pp. 99-111 ◽

Cited By ~ 1

Author(s):

Tihiro Ohkawa

Keyword(s):

Aspect Ratio ◽

Small Aspect Ratio ◽

Mhd Equilibrium

Download Full-text

Sewage Treatment in Helophyte Beds–First Experiences with a New Treatment Procedure

Water Science & Technology ◽

10.2166/wst.1987.0091 ◽

1987 ◽

Vol 19 (10) ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

K. Bucksteeg

Keyword(s):

Waste Water ◽

Rural Areas ◽

Root Zone ◽

Waste Water Treatment ◽

Sewage Treatment ◽

Uptake Capacity ◽

Humid Climate ◽

Climate Conditions ◽

Trickling Filters ◽

Operation Conditions

Waste water treatment in helophyte beds under humid climate conditions has been favoured by some German ecologists for some years. The idea is to cause waste water to flow horizontally through the root zone of helophytes to achieve satisfactory effluent properties. There exist many highly different proposals regarding the choice of soil and helophytes to be applied, bed area, design of inlets and outlets and operation conditions. A few plants have been operated in practice for some years. It appears that clogging is one of the main problems occurring in these plants. The hydraulic uptake capacity of soil is discussed in Darcy's law. Comparisons with observations of plants in operation are drawn. The interactions between soil properties, its uptake capacity, BOD5-, COD-, N- and P-reduction are evaluated. The effluent results of helophyte beds are compared with those of low-loaded trickling filters and of ponds used for sewage treatment in small villages in rural areas of Germany. It has been proved that the total construction costs of sewage treatment plants with helophyte beds used as the biological stage are higher when compared with those of conventional plants in general.

Download Full-text

Study on the Convective Heat Transfer and Fluid Flow of Mini-Channel with High Aspect Ratio of Neutron Production Target

Energies ◽

10.3390/en14134020 ◽

2021 ◽

Vol 14 (13) ◽

pp. 4020

Author(s):

Peng Sun ◽

Yiping Lu ◽

Jianfei Tong ◽

Youlian Lu ◽

Tianjiao Liang ◽

...

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Aspect Ratio ◽

Optimization Design ◽

Heat Dissipation ◽

Neutron Production ◽

Thermal Design ◽

Maximum Deviation ◽

Test Channel ◽

Production Target

In order to provide a theoretical basis for the thermal design of the neutron production target, flow and heat transfer characteristics are studied by using numerical simulations and experiments. A rectangular mini-channel experimental model consistent with the geometric shape of the heat dissipation structure of neutron production target was established, in which the aspect ratio and gap thickness of the test channel were 53.8:1 and 1.3 mm, respectively. The experimental results indicate that the critical Re of the mini-channel is between 3500 and 4000, and when Re reaches 21,000, Nu can reach 160. The simulation results are in good agreement with the experimental data, and the numerical simulation method can be used for the variable structure optimization design of the target in the later stage. The relationship between the flow pressure drop of the target mini-channel and the aspect ratio and Re is obtained by numerical simulation. The maximum deviation between the correlation and the experimental value is 6%.

Download Full-text