Building Configurations Research Articles

Dispersion Characteristics of PM10 Particles Identified by Numerical Simulation in the Vicinity of Roads Passing through Various Types of Urban Areas

The dispersion of particulate matter emitted by road transport to the vicinity of roads is predominantly influenced by the character of the air velocity field. The air flow depends on factors such as the speed and direction of the blowing wind, the movement of cars, and the geometries of the buildings around a road. Numerical modeling based on the control volume method was used in this study to describe the relevant processes closely. Detailed air velocity fields were identified in the vicinity of a straight road surrounded by various patterns of built-up urban land. The evaluation of the results was generalized to exponential expressions, affecting the decrease of the mass concentration of fine particles with the increasing distance from the road. The obtained characteristics of the mass concentration fields express the impact of the building geometries and configurations on the dispersion of particulate matter into the environment. These characteristics are presented for two wind speeds, namely, 2 m·s−1 and 4 m·s−1. Furthermore, the characteristics are introduced in relation to three wind directions: perpendicularly, obliquely, and in parallel to the road. The results of the numerical simulations are compared with those obtained via the in-situ measurements, for verification of the validity of the linear emission source calculation.

The Effect of Deep Energy Retrofit on The Hourly Power Demand of Finnish Detached Houses

This study examines how the energy renovation of old detached houses affects the hourly power consumption of heating and electricity in Finland. As electrification of heating through heat pumps becomes more common, the effects on the grid need to be quantified. Increased fluctuation and peak power demand could increase the need for fossil-based peaking power plants or call for new investments to the distribution infrastructure. The novelty in this study is the focus on hourly power demand instead of just annual energy consumption. Identifying the influence of building energy retrofits on the instantaneous power demand can help guide policy and investments into building retrofits and related technology. The work was done through dynamic building simulation and utilized building configurations obtained through multi-objective optimization. Deep energy retrofits decreased both the total and peak heating power consumption. However, the use of air-source heat pumps increased the peak power demand of electricity in district heated and wood heated buildings by as much as 100%. On the other hand, peak power demand in buildings with direct electric heating was reduced by 30 to 40%. On the building stock level, the demand reduction in buildings with direct electric heating could compensate for the increase in the share of buildings with ground-source heat pumps, so that the national peak electricity demand would not increase. This prevents the increase of demand for high emission peaking power plants as heat pump penetration rises. However, a use is needed for the excess solar electricity generated by the optimally retrofitted buildings, because much of the solar electricity cannot be utilized in the single-family houses during summer.

RETRACTED ARTICLE: Non functional requirement based software architecture scheme with security requirement using hybrid group search optimization and genetic algorithm

Managing non functional requirements has been a challenge onto software engineers for a long time. Throughout the years, numerous strategies and methods have been proposed to enhance their elicitation, documentation and approval. Similarly, security requirements emphatically impact the building configuration of complex IT frameworks comparatively as non-functional requirements. Both security building and software engineering furnish strategies to manage such necessities. Nonetheless, there is still a basic crevice concerning the joining of techniques for these two different fields. In this paper we close this crevice as for security prerequisites by proposing a technique that joins software engineering technologies with the best in class security engineering standards. An efficient quality requirement based software model with security requirements is developed by fusing Group Search Optimization and genetic algorithm in our proposed methodology.

Influence of the geometrical shape on the structural behavior of diagrid tall buildings under lateral and torque actions

Diagrid structural systems are more and more exploited worldwide for the realization of tall buildings, due to their versatility, their capability to realize complex-shaped constructions, and their efficiency in limiting lateral displacements. Plenty of research has been carried out in the last decade aimed at analyzing the structural behavior of these systems, mainly considering buildings with square or rectangular floor plans and commonly investigating only the lateral deformability of the structure. In this paper, we investigate the influence of some geometrical parameters on the structural response of diagrid tubular buildings, under both lateral and torque actions. To this aim, we make use of a matrix-based method (MBM), which was recently developed for the structural analysis of generic diagrid structures. Various building configurations, differing for the aspect ratio, the inclination of the external diagonals, and the floor plan shape, are considered and the structural solutions which allow to minimize the lateral displacements and torsional rotations are thoroughly surveyed.

Seismic Performance of Multi Storey RCC building Resting on Sloping Ground

In our day to day life increases Population. So that there is increasing basic need of human being. I.e. Food, Clothing, Shelter. In this, Shelter is most required in recently situation for protected from environment. Mostly we use level or plain ground for construction of houses. However, now it is very less for utilization of level land. Therefore, required more land to use for fulfillment human need. I.e. required to use of land on sloping ground also. When we construct building on sloping ground, it is irregular; centre of gravity and mass does not match to vertical and horizontal plane. So, while construction of Multi storey building on sloping ground required proper design and analysis. For analysis we consider four types of building configuration step back, set back, step back and set back frames and regular building on plain ground. Also, 10 and 12 storey considered. In that, base shear, displacement and storey drift find out and compare same with other building configuration by using ETABS Software.

Effect of Floor Shape Optimization on Energy Consumption for U-Shaped Office Buildings in the Hot-Summer and Cold-Winter Area of China

This paper explored the effects of the side proportion of building floor shape on building energy consumption. It is based on the analysis of regression models that were developed in the present study. The simplified building models can be used to conduct a parametric study to investigate the effect of building plane shape parameters on total heating and cooling load. DesignBuilder was used to build and simulate individual building configuration. Energy consumption simulations for forty-eight U-shaped buildings with different plane layouts were performed to create a comprehensive dataset covering general ranges of side proportions of U-shaped buildings and building orientations. Statistical analysis was performed using MATLAB to develop a set of regression equations predicting energy consumption and optimizing floor shapes. Furthermore, perimeter-area ratio (PAR), width ratio, and depth ratio were considered as three factors to characterize the quantitative relationship between floor shape and energy consumption. It is envisioned that the binary quadratic polynomial regression models, visualized as a smooth surface in space and mapped to a vortex image on the plane, can be used to estimate the energy consumption in the early stages of the design when different building schemes and design concepts are being considered.

Seismic Behaviour of Flat Slabs in High Rise Building

In the modern era, the growth of population has influenced the construction of high rise buildings day by day. The construction of the building structures with conventional RC slabs are in the public eye since many decades. Although it has more stiffness and minimizes the large moments occurred due to the applied loads, it does not have the advantages in terms of architectural flexibility, easier formwork and shorter construction period compared to the flat slabs. This developing technique of flat slabs construction improves aesthetical and structural aspect of tall building, offices, hospitals, shopping malls etc. As this is considered to be beamless slab, it has less shear strength and less stiffness compared to the conventional slabs. Due to its huge advantages, it is common in both the construction of regular and irregular buildings nowadays. From Structural engineer’s point of view, the flat slabs should be adopted with other structural component like shear walls and bracings for better results. The main motive of the present work is to compare and observe the seismic behaviour of regular and different configuration of irregular building in zone V by using different types of flat slabs. The considered G+13 storied buildings were analyzed with flat plate, drop panel, column head and combination of column head & drop panel by using E-tabs 17.0.1 software. The nonlinear time history method was carried out to observe the different parameters like storey displacement, storey drift, storey shear, base shear and time period following the guidelines of IS 1893 (Part 1): 2016

A comparison between the daylighting and energy performance of courtyard and atrium buildings considering the hot climate of Saudi Arabia

Daylighting is a healthy and energy-efficient building design strategy that has increasingly attracted the attention of researchers. This study investigates daylighting and the energy performance of courtyard and atrium office buildings, considering different window-to-wall ratios (WWR) applicable to the hot climate of Saudi Arabia. In such a climate, it is recommended to reduce window area and use shading devices in addition to the shaded daylighting elements such as courtyards and atria. This study analysed several cases in this regard and found that the examined courtyard and atrium building configurations presented equivalent cooling and artificial lighting energy performance in general. As for daylighting performance, the most balanced option of those examined was the use of a moderate WWR value of 30%, given that shading devices were used. This moderate value provided a better balance between daylight availability and glare reduction. Increasing WWR to 40% or 50% would only increase cooling energy demand and visual discomfort through glare.

Analytical evaluation of damage probability matrices for hill-side RC buildings using different seismic intensity measures

In the present study seismic response and vulnerability of hill-side RC buildings, often observed in the Indian Himalayan region as well as in some other parts of the world were analytically investigated using non-linear dynamic analyses. The conducted analyses led to the development of seismic fragility functions based on three different ground-motion intensity measures, viz. peak ground acceleration, spectral acceleration at the fundamental building period, and average spectral accelerations over a range of periods. In addition to the different code design levels that are considered in the assessment, the choice of the ground-motion intensity measure as well as the structural configuration type of these hill-side buildings show quite significant effects on the resulted damage probabilities of different damage states, and thus on the computed mean damage ratio. The peak ground acceleration results in a significant overestimation of the mean damage ratio for the maximum considered earthquake hazard level when compared with the spectral acceleration-based intensity measures. On the other hand, the irregular structural configuration of hill-side buildings alone results in a significantly higher mean damage ratio when compared with regular structural configuration. In addition to the design code level, the need to incorporate both of these effects, i.e. the choice of ground-motion intensity measure and irregular structural configurations of hill-side buildings, in the next generation of earthquake loss estimation studies and software tools is underlined.

Immersogeometric thermal analysis of flows inside buildings with reconfigurable components

The design and operation of energy sustainable buildings rely on the comprehensive understanding of how ventilation flows are influenced by different configurations. In this work, we present an immersogeometric framework for the thermal analysis of turbulent flows inside or around geometrically complex designs for this purpose. The framework utilizes a variational multiscale method to model the incompressible turbulent flows. We propose a streamline/upwind Petrov–Galerkin formulation for the advection–diffusion equation of energy balance and augment it with a discontinuity-capturing operator. Boundary representations (B-rep) of reconfigurable component designs are immersed into the background non-boundary-fitted fluid mesh, circumventing the labor-intensive and time-consuming boundary-fitted mesh generation process. Thermofluid analysis inside several building configurations is performed. The results demonstrate the potential of our immersogeometric framework in supporting the further investigations of energy-efficient sustainable buildings.

Impact hydrodynamique des vagues contre les bâtiments

Les tsunamis, les vagues d'impulsion et les ruptures de barrages représentent des phénomènes extrêmes qui mettent en danger la vie des personnes et la fonctionnalité des infrastructures. Des événements récents dans l'Océan Indien (2004), au Japon (2011) et en Indonésie (2018) ont montré que des mesures constructives peuvent réduire les charges induites sur les structures, et l'objectif de cette étude est d'évaluer et d'analyser le dommage potentiel des bâtiments frappés par des vagues. Au travers d'un programme expérimental étendu, cette recherche d'abord caractérise le comportement hydrodynamique des vagues sur fond sec et sur fond mouillé en termes de la célérité du front, des hauteurs d'eau et des profils de vitesse derrière le front. Ensuite, l'avantage d'avoir des bâtiments perméables pour réduire les hauteurs d'eau et les sollicitations en cas d'inondation est démontré. En outre, cette étude introduit des formules simples pour prédire la charge hydrodynamique sur un bâtiment, en tenant compte de l'effet des ouvertures au travers d'un coefficient de résistance adapté. Ces résultats fournissent des informations importantes pour le dimensionnement d'infrastructures plus sûres, qui puissent agir comme refuges verticaux en cas de dangers naturels liés à l'eau.

Toward efficient energy consumption in middle income housing buildings in Egypt

Abstract Current research pays special attention to the application of approaches that promote sustainable design in a built environment and ensure energy efficiency. In this context, the form of housing buildings is an important parameter that has a meaningful impact on the use of energy in housing buildings. Hence, this research attempts to study the impact of the form of housing buildings on energy efficiency taking into account the mid-hot weather conditions in one of the middle-income housing buildings in new communities in Egypt. To achieve the research aim, a comparative analysis is carried out using parametric numerical analysis—DesignBuilder energy analysis—to compare the various hypothetical proposals for different building configurations. The study determines that the efficiency of energy use in buildings depends to a large extent on their forms that will help urban designers and planners to propose the best energy performance in the form of housing buildings in the stage of conceptual design suitable for other environmental, social and economic urban planning issues. These results should be incorporated into the building codes adopted in Egypt’s new cities in order to reach more energy-efficient housing buildings in Egypt.

Monitoring and Modeling Roof-Level Wind Speed in a Changing City

Results of an observational campaign and model study are presented demonstrating how the wind field at roof-level in the urban area of Vienna changed due to the construction of a new building nearby. The investigation was designed with a focus on the wind energy yield of a roof-mounted small wind turbine but the findings are also relevant for air dispersion applications. Wind speed profiles above roof top are simulated with the complex fluid dynamics (CFD) model MISKAM (Mikroskaliges Klima- und Ausbreitungsmodell, microscale climate and dispersion model). The comparison to mast measurements reveals that the model underestimates the wind speeds within the first few meters above the roof, but successfully reproduces wind conditions at 10 m above the roof top (corresponding to about 0.5 times the building height). Scenario simulations with different building configurations at the adjacent property result in an increase or decrease of wind speed above roof top depending on the flow direction at the upper boundary of the urban canopy layer (UCL). The maximum increase or decrease in wind speed caused by the alternations in building structure nearby is found to be in the order of 10%. For the energy yield of a roof-mounted small wind turbine at this site, wind speed changes of this magnitude are negligible due to the generally low prevailing wind speeds of about 3.5 m s−1. Nevertheless, wind speed changes of this order could be significant for wind energy yield in urban areas with higher mean wind speeds. This effect in any case needs to be considered in siting and conducting an urban meteorological monitoring network in order to ensure the homogeneity of observed time-series and may alter the emission and dispersion of pollutants or odor at roof level.

Pressure distribution around the thermal envelope - a parametric study of the impact from wind and temperature on contaminant transport within a building

Several school buildings in Sweden have indoor air quality problems. The contaminant source is often assumed to come from within the construction, for example from the crawl space or attic space. Contaminants, in these cases, are transported by air leaking between compartments in the building. Here, the driving force for the air leakage is difference in pressure and, therefore, determining pressure also determines the direction of contaminant transport. In many cases, measures to improve the air quality are taken without a thorough understanding of how it might affect the pressure distribution in the building. In this paper a numerical model is used to examine how different climate scenarios and different building configurations affect the leakage and contaminant transport in a building with a crawl space. Results show that for leaky buildings the ventilation rate increases with increased wind and therefore the contaminant concentration decreases. The worst scenario in terms of high contaminant concentration is mild days with little wind. Also, when installing an exhaust fan in the crawl space with the purpose to prevent air from leaking from the crawl space to the classroom it is advisable to also consider the airtightness and the climate, not only the pressure difference across the floor.

Flow Characteristics Around Step-Up Street Canyons with Various Building Aspect Ratios

We investigate the flow characteristics around step-up street canyons with various building aspect ratios (ratio of along-canyon building length to street-canyon width, and upwind building height to downwind building height) using a computational fluid dynamics (CFD) model. Simulated results are validated against experimental wind-tunnel results, with the CFD simulations conducted under the same building configurations as those in the wind-tunnel experiments. The CFD model reproduces the measured in-canyon vortex, rooftop recirculation zone above the downwind building, and stagnation point position reasonably well. We analyze the flow characteristics, focusing on the structural change of the in-canyon flows and the interaction between the in- and around-canyon flows with the increase of building-length ratio. The in-canyon flows undergo development and mature stages as the building-length ratio increases. In the development stage (i.e., small building-length ratios), the position of the primary vortex wanders, and the incoming flow closely follows both the upstream and downstream building sidewalls. As a result, increasing momentum transfer from the upper layer contributes to a momentum increase in the in-canyon region, and the vorticity in the in-canyon region also increases. In the mature stage (i.e., large building-length ratios), the primary vortex stabilizes in position, and the incoming flow no longer follows the building sidewalls. This causes momentum loss through the street-canyon lateral boundaries. As the building-length ratio increases, momentum transfer from the upper layer slightly decreases, and the reverse flow, updraft, and streamwise flow in the in-canyon region also slightly decrease, resulting in vorticity reduction.

Influence of Real Ground Motion Records in Performance Assessment of RC Buildings

Reinforced concrete frame buildings with Open Ground Story (OGS) are one of the most common building configurations in urban habitat. These configurations are known to be vulnerable to seismic excitations, primarily due to the sudden loss in strength in the ground story and differential stiffness distribution throughout the structure. The differential stiffness distribution is attributed primarily to the interaction of non-structural infill wall with the moment-resisting frame. Hence, the interaction of infill wall needs to be accounted in estimating the seismic vulnerability. Therefore, the present investigation is focused on understanding the impact of utilizing real ground motion records on the performance assessment of RC buildings with and without consideration of infill walls. Fragility curves were developed for low and mid-rise structural models using Capacity Spectrum Method (CSM) specified by ATC-40 and with Incremental Dynamic Analysis (IDA). CSM uses the response spectrum specified by the respective code, unlike IDA where an ensemble of spectrum compatible real ground motion accelerograms satisfying the necessary site conditions is used in assessing the performance. Further, significant variations observed in the developed fragility curves by CSM and IDA emphasizes the sensitivity of real ground motion data in performance assessment.

Comparative Study of the Social Interactions of Two Differently Designed Long-Term Care Facilities for Individuals With Acquired Brain Injury.

This study focused on long-term care (LTC) settings for individuals with acquired brain injury (ABI). The goals were (1) to assess the impact of facility configuration on social interactions between residents and staff and (2) obtain a better understanding of staff and resident perceptions of the built environment. A few studies have explored the relationship between the built environment and social interaction in LTC facilities, but there is little empirical data about ABI-specific LTC facilities. A literature review was conducted on the impact of the built environment on the LTC of brain injury survivors. Via a questionnaire, staff and residents in two settings, one with patient rooms off corridors and the other with patient rooms surrounding a common space, rated the effectiveness of the built environment in promoting social interaction. Behavioral observation was conducted on 18 residents for a duration of 4 hr per resident. Via questionnaires, staff rated the corridor facility as more effective in promoting social interaction, but no significant differences were found between the assessments of the two resident populations. Contrary to staff questionnaire results, residents in the open configuration facility exhibited more social behaviors. Building configuration may impact social interaction between staff and residents in ABI-specific LTC facilities and potentially impact staff and resident quality of life. However, configuration cannot be viewed in a vacuum; residents' physical and mental limitations, demographic information, and staff engagement must be also considered.

Pedestrian-level wind environment near a super-tall building with unconventional configurations in a regular urban area

Unconventional configurations of tall buildings are noticeably different from their counterpart of traditional building designs but nevertheless, the unconventional configurations have often been adopted for tall buildings without their impact on the pedestrian-level wind environment (PLWE) fully understood. To fill the existing knowledge gap, this study investigates the PLWE near a 400 m super-tall building with various conventional and unconventional configurations in a regular urban area. Computational fluid dynamics (CFD) simulations were conducted for three incident wind directions (θ = 0°, 22.5°, and 45°) to investigate mean wind speed at the pedestrian level using the three-dimensional (3D), steady-state, Reynolds-averaged Navier-Stokes (RANS) technique. The results reveal 1.5- to 2.5-fold increase in maximum wind speed in the urban area after the construction of a super-tall building. The magnitude of the maximum wind speed and areas with high and low wind speeds in the PLWE, however, significantly vary with building design and incident wind direction. The configurations with sharp corners, large plan aspect ratios and frontal areas and the orientation consistently show a strong dependency on incident wind direction except the one with rounded plan shapes. The location of building openings and direction of building inclination are two other factors that modify the PLWE in an urban area. Moreover, the projected width of the super-tall building at a height slightly above the roof level of surrounding buildings is critical for estimating the areas of high and low wind speed at the pedestrian level.

The impact of building configurations and anthropogenic heat on daily urban air temperature cycles

Urban air temperature reflects the impact of urbanization on thermal and dynamics of urban climate. To understand the physical mechanism of building configurations and anthropogenic heat on daily urban air temperature cycles, an improved lumped urban air temperature model was provided. The surface energy balance equation for the improved and previous lumped urban air temperature model were compared. The effective depth of thermal mass and sub-surface temperature of urban surfaces in the previous model can be determined, which are usually chosen from model studies. These two parameters have a significant impact on the thermal storage. The models were evaluated and applied to the city of Hong Kong. Thermal storage is shown to have significant impact on the amplitude and phase term of daily air temperature cycle. Moreover, the building configurations can affect the solar radiation gain and redistribution in the sub-facets, which indirectly influenced the urban air temperature. The results show that the ventilation rate, building height and plan area ratio play important roles on daily cycle of urban air temperature, while the anthropogenic heat plays a less significant role. The main distinction of the improved model is its simplicity and less computation cost for practice use for engineers and urban planners. Two important parameters are emphasized, relative convective heat transfer number, λ, and time constant, τ. The two parameters provide some insights on how to control the urban thermal environment in an engineering way.

Experimental study on cross-ventilation of a generic building in highly-dense urban areas: Impact of planar area density and wind direction

This study presents the experimental results on cross-ventilation in a generic low-rise building placed in highly-dense urban configurations. Flow visualization studies were conducted by utilization of a smoke generator in order to investigate the nature of the flow pattern inside and around the cross-ventilated building. Moreover, distribution of the wind surface pressure coefficients over windward and leeward façades and internal walls of the target building were measured using a pressure tap system. Furthermore, the airflow rate crossing through the openings was measured using a tracer gas method. Different building configurations, representing highly-dense urban areas, as well as different wind angles were investigated in this study.Surprisingly, the experimental results reveal a noticeable difference between the mechanism of cross-ventilation in moderately-dense and highly-dense buildings arrangements. A clear leeward jet with a highly-transient nature can be observed, which is generated due to a leeward vortex formed by the target and downstream buildings. As another novel finding of this study, the cross-ventilation is understood to be highly transient in highly-dense urban areas with a strong periodic fresh air pulsation through the windward and leeward openings. This behavior is fundamentally far from the steady state models considered for such cross-ventilation scenarios in literature.