scholarly journals Evaluation of Daylight Parameters on the Basis Simulation Model For the Tropical Climate

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Trupti Jagdeo Dabe ◽  
Vinayak S. Adane
Keyword(s):  
Thermal Energy ◽  
Field Measurements ◽  
Excess Energy ◽  
Design Tool ◽  
Simulation Studies ◽  
Dwelling Unit ◽  
Simulated Model ◽  
Percentage Difference ◽  
Illuminance Level ◽  
Shading Devices

Use of natural daylight in the building is energy saving with respect to illumination levels and health benefits. However in, the hot and dry climatic zone increase in daylight availability may result into thermal ingress. This might lead to excess energy conservation. The aim of this paper is to evolve the methodology which could be used as a pre design tool for assessing the lighting provisions and thermal performance of spaces within buildings adopted by designers during the design process. The field measurements were conducted on the liveable spaces of a dwelling unit of the Nagpur region. Simulation studies using Ecotect Analysis 2011 was conducted for both illumination and thermal energy. The field measurements were compared with the simulated results. It has been found that the percentage difference (PD) between the Ecotect measurements (EM) and field measurements (FM) for both thermal loads and an illuminance level was less than 15%, the simulated model was considered precise for further study. The result imply that the simulated model would be ample for designers to evaluate the parameters associated to wall to window ratio, shading devices with respect to orientation of the building which helps to achieve the optimum useful daylight index.

System Design and Modeling of a Thermally Activated Reconfigurable Wing

2010 ◽  
Author(s):  
Richard Beblo ◽  
Darrel Robertson ◽  
James Joo ◽  
Brian Smyers ◽  
Gregory Reich
Keyword(s):  
Thermal Energy ◽  
High Speed ◽  
Frictional Heating ◽  
Mechanical Analysis ◽  
Design Tool ◽  
System Level ◽  
Morphing Aircraft ◽  
Thermal Actuation ◽  
Short Period ◽  
Reconfigurable Structures

Reconfigurable structures such as morphing aircraft generally require an on board energy source to function. Frictional heating during the high speed deployment of a blunt nosed low speed reconnaissance air vehicle can provide a large amount of thermal energy during a short period of time. This thermal energy can be collected, transferred, and utilized to reconfigure the deployable aircraft. Direct utilization of thermal energy has the ability to significantly decrease or eliminate the losses associated with converting thermal energy to other forms, such as electric. The following work attempts to describe possible system designs and components that can be utilized to transfer the thermal energy harvested at the nose of the aircraft during deployment to internal components for direct thermal actuation of a reconfigurable wing structure. A model of a loop heat pipe is presented and used to predict the time dependant transfer of energy. Previously reported thermal profiles of the nose of the aircraft calculated based on trajectory and mechanical analysis of the actuation mechanism are reviewed and combined with the model of the thermal transport system providing a system level feasibility investigation and design tool. The efficiency, implementation, benefits, and limitations of the direct use thermal system are discussed and compared with currently utilized systems.

scholarly journals Performance Analysis of Photovoltaic Integrated Shading Devices (PVSDs) and Semi-Transparent Photovoltaic (STPV) Devices Retrofitted to a Prototype Office Building in a Hot Desert Climate

2020 ◽  
Vol 12 (23) ◽  
pp. 10145
Author(s):  
Abdelhakim Mesloub ◽  
Aritra Ghosh ◽  
Mabrouk Touahmia ◽  
Ghazy Abdullah Albaqawy ◽  
Emad Noaime ◽  
...  
Keyword(s):  
Essential Feature ◽  
Field Measurements ◽  
Energy Performance ◽  
Office Building ◽  
Visual Comfort ◽  
Extra Energy ◽  
Shading Devices ◽  
Parametric Analyses ◽  
The Impact ◽  
Desert Climate

This paper presents the impact on energy performance and visual comfort of retrofitting photovoltaic integrated shading devices (PVSDs) to the façade of a prototype office building in a hot desert climate. EnergyPlus™ and the DIVA-for-Rhino© plug-ins were used to perform numerical simulations and parametric analyses examining the energy performance and visual comfort of five configurations, namely: (1) inclined single panel PVSDs, (2) unfilled eggcrate PVSDs, (3) a louvre PVSD of ten slats tilted 30° outward, (4) a louvre PVSD of five slats tilted 30° outward, and (5) an STPV module with 20% transparency which were then compared to a reference office building (ROB) model. The field measurements of an off-grid system at various tilt angles provided an optimum tilt angle of 30°. A 30° tilt was then integrated into some of the PVSD designs. The results revealed that the integration of PVSDs significantly improved overall energy performance and reduced glare. The unfilled eggcrate PVSD did not only have the highest conversion efficiency at ȵ 20% but generated extra energy as well; an essential feature in the hot desert climate of Saudi Arabia.

Antarctic rock weathering simulations: simulator design, application and use

1989 ◽  
Vol 1 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Kevin Hall ◽  
Alan Cullis ◽  
Chris Morewood
Keyword(s):  
Field Measurements ◽  
Laboratory Simulation ◽  
Simulation Studies ◽  
Maritime Antarctic ◽  
Simulation Based ◽  
Simulator Design ◽  
Antarctic Research ◽  
Computer Controlled ◽  
Mechanical Weathering ◽  
The Antarctic

The design of a computer-controlled climatic simulation cabinet used for mechanical weathering studies on Antarctic rocks is described. It is argued that if the results of simulations are to be applicable to field situations they should be firmly based on field environmental conditions. Some weathering results from a laboratory simulation based upon microclimatic data collected from the maritime Antarctic are presented and it is shown that they could not have been obtained from field measurements alone. Further simulation studies are required for the Antarctic and it is argued that the nature of Antarctic research is such that it is particularly conducive to this type of approach.

scholarly journals Visual and acoustic performance of shading devices – real scale laboratory measurements

2019 ◽  
Vol 111 ◽  
pp. 06072 ◽  
Author(s):  
Tiberiu Catalina ◽  
Alexandra Ene ◽  
Andreea Biro
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Point Of View ◽  
Physical Parameters ◽  
Main Role ◽  
Reverberation Time ◽  
Illuminance Level ◽  
Shading Devices ◽  
Enclosed Space

There are several physical parameters that are taken into consideration when determining the level of agreeability of an enclosed space. For instance, when choosing the louvers for a room there are a multitude of criteria that might be considered such as colour, material or the degree of opacity. However, these apparently small fixtures may have a significant impact also on other apparently unimportant factors like the sound pressure level and the reverberation time. This paper aims to present different types of devices used to control the way daylight enters a room, from both the illuminance level and the acoustical point of view. During the experimental campaign, five of the most common types of louvers were examined regarding their main role of blocking the light and moreover their influence on the reverberation time and sound pressure level in the analysed chamber.

scholarly journals Remote Sensing of Secchi Depth in Highly Turbid Lake Waters and Its Application with MERIS Data

2019 ◽  
Vol 11 (19) ◽  
pp. 2226 ◽  
Author(s):  
Xiaohan Liu ◽  
Zhongping Lee ◽  
Yunlin Zhang ◽  
Junfang Lin ◽  
Kun Shi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Lake Taihu ◽  
Secchi Depth ◽  
Field Measurements ◽  
Water Clarity ◽  
Temporal Variations ◽  
Inland Waters ◽  
Percentage Difference ◽  
The One ◽  
Turbid Inland Waters

The Secchi disk depth (ZSD, m) has been used globally for many decades to represent water clarity and an index of water quality and eutrophication. In recent studies, a new theory and model were developed for ZSD, which enabled its semi-analytical remote sensing from the measurement of water color. Although excellent performance was reported for measurements in both oceanic and coastal waters, its reliability for highly turbid inland waters is still unknown. In this study, we extend this model and its evaluation to such environments. In particular, because the accuracy of the inherent optical properties (IOPs) derived from remote sensing reflectance (Rrs, sr−1) plays a key role in determining the reliability of estimated ZSD, we first evaluated a few quasi-analytical algorithms (QAA) specifically tuned for turbid inland waters and determined the one (QAATI) that performed the best in such environments. For the absorption coefficient at 443 nm (a(443), m−1) ranging from ~0.2 to 12.5 m−1, it is found that the QAATI-derived absorption coefficients agree well with field measurements (r2 > 0.85, and mean absolute percentage difference (MAPD) smaller than ~39%). Furthermore, with QAATI-derived IOPs, the MAPD was less than 25% between the estimated and field-measured ZSD (r2 > 0.67, ZSD in a range of 0.1–1.7 m). Furthermore, using matchup data between Rrs from the Medium Resolution Imaging Spectrometer (MERIS) and in-situ ZSD, a similar performance in the estimation of ZSD from remote sensing was obtained (r2 = 0.73, MAPD = 37%, ZSD in a range of 0.1–0.9 m). Based on such performances, we are confident to apply the ZSD remote sensing scheme to MERIS measurements to characterize the spatial and temporal variations of ZSD in Lake Taihu during the period of 2003–2011.

Comparative Performance of a Solar Screen With Respect to Perforation Ratio: Illuminance and Energy Saving

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Esam M. Alawadhi
Keyword(s):  
Design Patterns ◽  
Building Design ◽  
Visual Environment ◽  
Negative Effects ◽  
Comparative Performance ◽  
Heat Gain ◽  
Indoor Space ◽  
Illuminance Level ◽  
Shading Devices ◽  
The Impact

The objectives of sustainable building design are to provide the comfort to the occupants and to eliminate negative environmental impacts of its operations. In this regard, windows play a crucial role in saving energy used for electrical lights and enhancing the indoor visual environment. Excessive sunlight penetration through the windows could increase the heat gains and create the uncomfortable visual environment. Hence, external shading devices, such as solar screens, control the sunlight penetration and minimize its negative effects. The objectives of this research are to provide new insight into the impact of installing the solar screen on the indoor visual environment and heat gain through the window. Experimental measurements are conducted in extreme weather month and window direction, in June and for West facing façade window. Three design patterns of the solar screen were considered with perforation ratios of 12.5%, 25%, and 35%. Without a solar screen, the results show that there is a significant illuminance level variation in the indoor space, between 200 and 2250 Lux. However, if a solar screen with 12.5% perforation ratio is installed, the illuminance level in entire indoor space becomes uniform, it is maintained at 400 Lux during the daytime, and thereby visual comfort is attained. Additionally, the heat gain through the window is decreased by 52.8%, and the window is prevented from heating up during the daytime.

scholarly journals The Impact of Façade Orientation and Woody Vegetation on Summertime Heat Stress Patterns in a Central European Square: Comparison of Radiation Measurements and Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Noémi Kántor ◽  
Csilla Viktória Gál ◽  
Ágnes Gulyás ◽  
János Unger
Keyword(s):  
Heat Stress ◽  
Model Comparison ◽  
Field Measurements ◽  
Measurement Model ◽  
Woody Vegetation ◽  
Primary Role ◽  
Modeling Software ◽  
Shading Devices ◽  
Radiant Temperature ◽  
The Impact

Increasing summertime air temperature deteriorates human health especially in cities where the warming tendency is exacerbated by urban heat island. Human-biometeorological studies shed light on the primary role of radiation conditions in the development of summertime heat stress. However, only a limited number of field investigations have been conducted up to now. Based on a 26-hour long complex radiation measurement, this study presents the evolved differences within a medium-sized rectangular square in Szeged, Hungary. Besides assessing the impact of woody vegetation and façade orientation on the radiation heat load, different modeling software programs (ENVI-met, SOLWEIG, and RayMan) are evaluated in reproducing mean radiant temperature (Tmrt). Although daytimeTmrtcan reach an extreme level at exposed locations (65–75°C), mature shade trees can reduce it to 30–35°C. Nevertheless, shading from buildings adjacent to sidewalks plays also an important role in mitigating pedestrian heat stress. Sidewalks facing SE, S, and SW do not benefit from the shading effect of buildings; therefore, shading them by trees or artificial shading devices is of high importance. The measurement–model comparison revealed smaller or larger discrepancies that raise awareness of the careful adaptation of any modeling software and of the relevance of fine-resolution field measurements.

An Experimental Study on Heterogeneous Porous Stacks in a Thermoacoustic Heat Pump

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Syeda Humaira Tasnim
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Field Measurements ◽  
Clean Energy ◽  
Vitreous Carbon ◽  
High Price ◽  
Heat Engines ◽  
Energy Demands ◽  
Conversion Technologies ◽  
Stack Design

Growing evidence suggests that research must be done to develop energy efficient systems and clean energy conversion technologies to combat the limited sources of fossil fuel, its high price, and its adverse effects on environment. Thermoacoustic is a clean energy conversion technology that uses the conversion of sound to thermal energy and vice versa for the design of heat engines and refrigerators. However, the efficient conversion of sound to thermal energy demands research on altering fluid, operational, and geometric parameters. The present study is a contribution to improve the efficiency of thermoacoustic devices by introducing a novel stack design. This novel stack consists of alternative conducting and insulating materials or heterogeneous materials. The author examined the performance of eight different types of heterogeneous stacks (combination 1–8) that are only a fraction of the displacement amplitude long and consisted of alternating aluminum (AL) and Corning Celcor or reticulated vitreous carbon (RVC) foam materials. From the thermal field measurements, the author found that combination eight performs better (12% more temperature difference at the stack ends) than all the other combinations. One interesting feature obtained from these experiments is that combination 7 produces the minimum temperature at the cold end (17% less than other combinations). The thermal performance of the heterogeneous stack is compared to that of the traditional homogeneous stack. Based on the study, the newly proposed stack design provides better cooling performance than a traditionally designed stack.

scholarly journals Energy-Saving Potential of Daylighting in the Atria of Colleges in Najran University, Saudi Arabia

2019 ◽  
Vol 7 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Abdultawab Mohammed Qahtan ◽  
Diaeldin A Ebrahim ◽  
Hussein M. Ahmed
Keyword(s):  
Saudi Arabia ◽  
Control System ◽  
Energy Saving ◽  
Energy Savings ◽  
Field Measurements ◽  
Medical Sciences ◽  
Energy Saving Potential ◽  
Time Scheduling ◽  
Illuminance Level ◽  
Present Case Study

Daylighting is recognised as an effective strategy for enhancing visual comfort and reducing energy used for electric lighting. Najran University, Saudi Arabia, has 15 colleges for males and 10 colleges for females. Each college has several atria and courtyards for introducing daylighting into the hearts of college buildings. However, the electrical lights used in the colleges atria and linked corridors keep on all the daytime. This study is an attempt to investigate the daylight illuminance level and energy-saving potential on the atria and linked corridors when it incorporates a time-scheduling lighting control system. The field measurements were performed in the College of Applied Medical Sciences. The results indicate that daylight illuminance in the atrium spaces are abundant with an average illumination level on the atrium floor varying from 300 lux to 3 600 lux, depending on the time of the day. In the clear sky climate of Najran city throughout the year, the time-scheduling control system is effective and found to contribute to approximately 43 855.2 kWh of annual energy savings in electrical-lighting consumption in the present case study scenario. The total annual energy savings from all 25 colleges at Najran University is 1 096 380 kWh/year, which results in a cost saving of approximately 93,512.86 USD. There would be additional substantial savings from other atria and courtyards in all of the college buildings throughout the campus

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