Effect of Hump Configurations of Porous Square Cavity on Free Convection Heat Transfer

Free convection is widely used in engineering applications, including solar energy, electronic devices, nuclear energy, and heat exchangers. A computational simulation utilizing Ansys Fluent-CFD was employed to examine the natural convection heat transfer inside a square cavity filled with pure water and saturated metal foam as a porous medium (porosity ɛ =0.9). The enclosure's lower wavy wall exhibits a high temperature (Th), while the side and upper walls have a low temperature (Tc). For different Rayleigh numbers, the study examines hump configuration and the bottom wall hump number (N). The predominant design of heat transmission was improved using the circular hump design parameters of ɛ=0.9, N=4 and Tc= 25C˚ for different Ra. This resulted in significant improvements in heat transfer enhancement and energy enhancement which were enhanced by 1.13 times, for both. The authenticity research included determining the optimal design for the square enclosure. This involved estimating the effects of hump configure and number of humps for bottom wall of enclosure. These parameters have not been studied yet. The optimum case showed the highest heat transfer coefficient (h) at circular hump, N=4 and Ra = 30´103. While the standard case had N=0 and Ra = 5´103. The CFD simulation results indicate that the primary objective of the study was achieved through the optimal design, which resulted in a significant enhancement of hydrothermal performance for both heat transfer enhancement and energy enhancement 1.13 times compared to standard case

Global technological advancement and challenges of glazed window, facade system and vertical greenery-based energy savings in buildings: A comprehensive review

There are many factors that have a major influence on reducing the energy expenditure in building sector. This research aims at qualitative and quantitative assessment of those factors such as double glazed windows, vertical greenery systems (VGS), integrating of semi-transparent photovoltaic device with architectural design of buildings, energy saving by using heat reflecting coating, passive climate control methods, energy saving by shading, building energy performance enhancement by using optimisation technique, double skin green facade, etc. through a holistic and thematic approach. Amongst the aforesaid techniques, VGS is found the most reliable, efficient and sustainable solution. Attractive VGS can improve the urban environment, increase biodiversity, mitigate pollution also results economic benefit of the buildings as like as energy savings and decreasing surface temperature. Four fundamental energy saving methods are used in VGS which are considered as passive energy saving mechanism. Firstly, interception of solar radiation due to the shadow risen by the vegetation; secondly, vegetation also provides thermal insulation; thirdly, plants evapotranspiration helps for evaporative cooling of building; finally, building blockage makes a variation of wind effect on building. The peak cooling load of ivy coated green building wall has been reduced by 28%. If a VGS is installed without windows and building facing on west, east, south and north correspondingly, the reduction in the cooling load capacity of the building is observed to be up to 20, 18, 8 and 5%, respectively. Very high thermally resistive glazed areas on building envelope can be secured via thin film PV glazing and vacuum glazing products with an average U-value of 1.1 and 0.4 W/m2K, respectively. Energy use policies are also helpful to improve energy consumption scenario of buildings. For developing more energy-efficient, sustainable and eco-friendly buildings, these techniques might be helpful for the building designers and architects