An Experimental Study of Radiant Cooling for Buildings in a Tropical Climate

2012 ◽  
Vol 622-623 ◽  
pp. 1570-1574
Author(s):  
W. Prasertsak ◽  
S. Wongkee ◽  
P. Chaiwiwatworakul ◽  
S. Chirarattananon
Keyword(s):  
Experimental Study ◽  
Convective Heat Exchange ◽  
Simple Calculation ◽  
Tropical Climate ◽  
Heat Extraction ◽  
Extraction Capacity ◽  
Comfort Index ◽  
Radiant Cooling ◽  
Measurement Results ◽  
Calculation Results

This paper presents an experimental study of radiant cooling for building air-conditioning in a tropical climate. To prevent condensation of moisture on the cooling panel, the temperature of chilled water supplied to the panel was limited to 25°C. This led to the limitations of heat extraction capacity at the panel and its application to only space with low thermal load and low metabolic rate activity of people in the space. A simple calculation of radiative and convective heat exchange between the interior room surfaces and the room air was applied to determine the rate of heat extraction by the panels. The calculation results can match well with the measurement results. Using a comfort index of predicted mean vote (PMV), the results from experiments show that thermal comfort could be achieved with the application of radiant cooling.

scholarly journals THERMAL COMFORT INVESTIGATION ON HOLY MOSQUE IN BANDUNG Case Study : Lautze 2 Mosque Bandung

2020 ◽  
Vol 2 (1) ◽  
pp. 82
Author(s):  
Agung Prabowo
Keyword(s):  
Thermal Comfort ◽  
Quantitative Research ◽  
Thermal Environment ◽  
Tropical Climate ◽  
Air Humidity ◽  
Air Velocity ◽  
Related Factors ◽  
Climate Conditions ◽  
Comfort Index ◽  
Main Factors

Abstract -Thermal comfort is a state of mind that expresses satisfaction with the thermal environment. There are two main categories in the effort to obtain a comfort index; empirical and analytical. Empirical is based on social surveys, while analysis is based on the physics principle of heat flow.Bandung city is one of the historical cities in Indonesia which has many historical heritage buidings. One of them which is commonly known as colonial buildings in Bandung is Lautze 2 Mosque, located at Tamblong Street in the city center of Bandung. This research was conducted to analyze the thermal comfort in the Lautze 2 Mosque Bandung. The analytical method used in this study is a quantitative research method by measuring the main factors namely air temperature, air humidity and air velocity. The main factors become obstacles to get thermal comfort data at the Lautze 2 Mosque Bandung is the location of buildings located in areas with tropical climate conditions with high air temperatures, high air humidity, and low air velocitys.The research conclude that thermal comfort in the Lautze 2 Mosque Bandung building can be categorized as uncomfortable, it can be seen from the measurement results of related factors, namely the temperature and humidity that exceeds the comfort limit and the low air velocity in the building becomes an obstacle to obtain thermal comfort. Keywords: colonial buildings, mosque, thermal comfort, tropical climate.

A simple calculation method for estimating the flow velocity on the roof of a train running through a tunnel using an unsteady incompressible flow model

2019 ◽  
Vol 234 (7) ◽  
pp. 734-748
Author(s):  
Katsuhiro Kikuchi ◽  
Satoru Ozawa ◽  
Yuhei Noguchi ◽  
Shinya Mashimo ◽  
Takanobu Igawa
Keyword(s):  
Boundary Layer ◽  
Flow Velocity ◽  
Calculation Method ◽  
Model Experiment ◽  
Flow Model ◽  
Simple Calculation ◽  
Dimensional Model ◽  
One Dimensional ◽  
Calculation Results ◽  
Tunnel System

Predicting the aerodynamic phenomena in a train-tunnel system is important for increasing the speed of railway trains. Among these phenomena, many studies have focused on the effects of pressure; however, only a few studies have examined the effects of flow velocity. When designing train roof equipment such as a pantograph and an aerodynamic braking unit, it is necessary to estimate the flow velocity while considering the influence of the boundary layer developed on the train roof. Until now, numerical simulations using a one-dimensional model have been utilized to predict the flow velocity around a train traveling through a tunnel; however, the influence of the boundary layer cannot be taken into consideration in these simulations. For this purpose, the authors have previously proposed a simple calculation method based on a steady incompressible tunnel flow model that can take into account the influence of the boundary layer, but this method could not incorporate the unsteadiness of the flow velocity. Therefore, in this study, the authors extend the previous simple calculation method such that it can be used for an unsteady incompressible tunnel flow. The authors compare the calculation results obtained from the extended method with the results of a model experiment and a field test to confirm its effectiveness.

scholarly journals Process-Induced Distortions Characterization of MBWK Fabric Reinforced Composite Helmet Shell

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2983
Author(s):  
He Xiang ◽  
Yaming Jiang ◽  
Yexiong Qi ◽  
Jialu Li
Keyword(s):  
Thin Shell ◽  
High Performance ◽  
Laser Scanning ◽  
Textile Composites ◽  
Reinforced Composite ◽  
Measurement Results ◽  
Calculation Results ◽  
High Performance Composite ◽  
Working Procedure

In order to characterize the process-induced distortions of 3D thin shell composites with complex shape, the multilayered biaxial weft knitted (MBWK) fabric reinforced high-performance composite helmet was selected as the research object, and the 3D laser scanning machine was used to scan the helmet surface, then the 3D scanning data was compared with the CAD model to evaluate the deformation. The results and discussion indicated that the conventional method was workable, but the speed of convergence was slow and the calculation results were easy to drop into local optimization. According to detailed analysis, a measurement method focusing on the principle of “Feature Distance” was developed. The measurement results shown that this method can not only give accurate results, but also reduce working procedure and greatly save the computing resources, which is proved to be a feasible approach for the deformation measurement foundation of 3D thin shell textile composites.

scholarly journals Calculating the load on the room cooling ceiling panel at convective heat gains

2020 ◽  
Vol 164 ◽  
pp. 02006
Author(s):  
Elena Malyavina ◽  
Alexander Lomakin
Keyword(s):  
Thermal Stability ◽  
Convective Heat ◽  
Convective Flow ◽  
Cooling System ◽  
Working Hours ◽  
Engineering Practice ◽  
Convective Heat Flux ◽  
Long Period ◽  
Radiant Cooling ◽  
Calculation Results

A well-known statement of the theory of thermal stability asserts that when a harmonically time-changing convective heat flux enters a room, it can only be assimilated by a radiant cooling system if the assimilating flow exceeds the perturbing convective flow in magnitude. However, in engineering practice, there are no purely radiant systems. Therefore, the article has considered a ceiling cooling panel as a room cooling system, the heat flow from which is of a radiant-convective nature. The convective heat access to the room is constant during the working hours from 9 a.m. to 6 p.m. The task of determining the load on the cooling system has been performed by calculations.. Herewith, the rooms of different internal thermal stability have been considered. According to the calculation results, it has been found that, since the amount of the heat gains remains constant for a long period of time, the process of the room cooling comes almost to a stationary state and does not depend on the room thermal stability with assimilated heat gains, the value of which in different options varied from 100 W to 1000 W. It has been found, that when the temperature difference between the panel surface and the surrounding surfaces increases, the proportion of the convective assimilating flow becomes bigger.

Experimental Research on Mechanical Calculation of Fascine Object’s Underwater Falling

2011 ◽  
Vol 84-85 ◽  
pp. 204-208
Author(s):  
Jie Shi ◽  
Xiao Lei Zhang ◽  
Su Ting Yang
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Experimental Research ◽  
Yellow River ◽  
The Yellow River ◽  
Mechanical Calculation ◽  
River Bed ◽  
Calculation Results

Fascine objects can be applied in the process of emergency rescues in the Middle and Lower reaches of the Yellow River. Because fascine objects can improve the efficiency of rushing to deal with an emergency, adapt to changes in river bed conditions better, resist the erosion of water slide on riverbank and buttress and prevent the collapse of the embankment, they are applicable to rescuing grave dangerous situations such as river closure, advancing construction dams in waters, closing up levee breaches and so on. Based on the experimental study, the authors analyze the mechanical calculation results of fascine object’s underwater falling, and draw the relevant mechanical properties of fascine object’s underwater falling.

An Experimental Study on Bioclimatic Design of Vertical Greenery Systems in the Tropical Climate

2014 ◽  
pp. 369-376
Author(s):  
Badrulzaman Jaafar ◽  
Ismail Said ◽  
Mohd Nadzri Md Reba ◽  
Mohd Hisham Rasidi
Keyword(s):  
Experimental Study ◽  
Tropical Climate ◽  
Bioclimatic Design
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