Assessment of the Thermal Performance of Vertical Green Walls Using Overall Thermal Transfer Value Based BIM Simulation Method: Case Study of Residential Buildings in Sub-Tropics

Construction of multifunctional building envelopes using vertical greenery walls (VGW) has emerged as a sustainable green technology to improving cooling efficiency. To attaining the desired level of building cooling performance, VGW and overall thermal transfer value (OTTV) of the walls are useful design factors. The study aims to revise the current VGW evaluation, considering the decreased heat flux due to thermal efficiency of wall construction based on OTTV values. To achieve this, OTTV based Building Information Modelling (BIM) simulation method was proposed using Autodesk-Revit and DesignBuilder simulation based on EnergyPlus. Six wall compositions with various OTTV values of south facade for residential buildings located in sub-tropical in cooling season, were evaluated. The findings demonstrate that in the presence of a green system, a good OTTV value of the exterior walls is required for optimal performance, to keep the space within set point of cooling for long time during the cooling season. The comparisons between the bare walls and the VGW have demonstrated a great variation due to the different OTTV reached up to 6.57% and 18.44% reduction in indoor air temperature. The best combination of VGW resulted a maximum of 1.2°C reduction in indoor air temperature, with number of hours (within 28°C or less) were higher by 2506h, representing 85.59% of the overall number of hours (2928h). Overall cooling energy saving is found as 103.3kwh, representing 13.63% of the total of energy saving, and decreased the heat gained by 38.82%, representing 61.51kwh reduction during cooling season compared to base wall.

Mechanical improvement in solar aircraft by using tangent hyperbolic single-phase nanofluid

Solar power is the primary thermal energy source from the sunlight. This research has carried out the study of solar aircraft with solar radiation in enhancing efficiency. The thermal transfer inside the solar aircraft wings using a nanofluid past a parabolic surface trough collector (PTSC) is investigated thoroughly. The source of heat is regarded as solar radiation. For several impacts, such as porous medium, thermal radiation, and varying heat conductivity, the heat transmission performance of the wings is examined. By using the tangent hyperbolic nanofluid (THNF), the entropy analysis has been performed. The modeled momentum and energy equations are managed using the well-established numerical methodology known as the finite difference method. Two distinct kinds of nano solid-particles have been examined, such as Copper (Cu) and Zirconium dioxide (ZrO2), while Engine Oil (EO) being regarded as a based fluid. Different diagram parameters will be reviewed and revealed as figures and tables on speed, shear stress, temperature, and the surface drag coefficient and Nüselt number. It is observed that in terms of heat transfer for amplification of thermal radiation and changeable thermal conductance parameters, the performance of the aircraft wings raises. In contrast to traditional fluid, nanofluid is the best source of heat transmission. Cu-EO's thermal efficiency over ZrO2-EG falls to the minimum level of 12.6% and has reached a peak of 15.3%.

Investigation of Carbon-Based Composites for Elastic Heaters and Effects of Hot Pressing in Thermal Transfer Process on Thermal and Electrical Properties

Wearable electronics are new structures with a wide range of possible applications. This study aims to analyze the effects of hot pressing in thermal transfer of different carbon-based composites as a new application method of screen-printed electronics on textiles. Flexible heaters were screen-printed on polyethylene terephthalate PET foil with composites based on graphene, carbon black, and graphite with different wt.%, measured and then hot pressed to measure and analyze differences. Research showed that the hot pressing process in thermal transfer resulted in decreased electrical resistance, increased power, and higher maximal temperatures. Best results were achieved with composites based on 12 wt.% graphene with sheet resistance lowered by about 40% and increased power by about 110%. This study shows promise for thermal transfer and screen-printing combination as an alternative for creating flexible electronics on textiles.

Entropy Analysis for Cilia-Generated Motion of Cu-Blood Flow of Nanofluid in an Annulus

In this study, a novel model of entropy generation effects measured in the Cu-blood flow of a nanofluid under the effect of ciliary-oriented motion is proposed. The effects of viscous dissipation are also taken into account. The physical model was composed with the incorporation of a low Reynolds number and long-wavelength phenomena. The exact solutions for the axial velocity, temperature and pressure gradient distribution were achieved successfully. Key findings are presented through a strategy of plotting the significant factors affecting the physical quantities of the stream. It was found that the heat absorption parameter and Brownian motion accounted for the large thermal transfer rate, while the effect of entropy was minimal compared to these factors in the center of the flow but increased on the walls in the case of Cu-blood flow. It can also be added that a more intense flow gave rise to the entropy effects. This study may be helpful in medical science as cilia play vital roles, which include cell migration and external fluid transport, in human tissues and some key organs. Moreover, the considered annulus-shaped geometry gives vital readings that are used in medical equipment such as endoscopes.

Green-Building-Index-Assessment-Criteria-Based Comparative Evaluation of Interlocking Blocks as an Alternative to Conventional Masonry for Residential Buildings in Malaysia

Major residential construction projects adopt clay bricks as masonry, which can contribute to high carbon emission, primarily due to their high embodied carbon. Furthermore, the adoption of conventional masonry, including clay bricks, may lead to the use of high amounts of mortar and contribute to a lot of wastage. Therefore, an alternative system that can potentially replace conventional masonry is required to reduce the wastage as well as carbon emission. Interlocking blocks, which adopt a lock and key system has the potential to replace conventional masonry as they employ locally available materials, save construction time, use less mortar and are less dependent on highly skilled masons. In view of their potential, the adoption of interlocking blocks in residential buildings were evaluated comparatively to conventional masonry, namely clay and cement sand bricks, based on the Green Building Index Assessment Criteria for Residential New Construction (GBI-RNC) tool. Overall Thermal Transfer Values of test models that employed conventional masonry and interlocking blocks were calculated. Approximately, based on the GBI-RNC tool, with an increase of 17-18 points achieved from the EE, MR and IN criteria, a Silver rating can be achieved with the adoption of interlocking blocks.