Papers by Luciano Caruggi
Integrative and Comparative Biology
Synopsis From large ventral pleats of humpback whales to nanoscale ridges on flower petals, wrink... more Synopsis From large ventral pleats of humpback whales to nanoscale ridges on flower petals, wrinkled structures are omnipresent, multifunctional, and found at hugely diverse scales. Depending on the particulars of the biological system—its environment, morphology, and mechanical properties—wrinkles may control adhesion, friction, wetting, or drag; promote interfacial exchange; act as flow channels; or contribute to stretching, mechanical integrity, or structural color. Undulations on natural surfaces primarily arise from stress-induced instabilities of surface layers (e.g., buckling) during growth or aging. Variation in the material properties of surface layers and in the magnitude and orientation of intrinsic stresses during growth lead to a variety of wrinkling morphologies and patterns which, in turn, reflect the wide range of biophysical challenges wrinkled surfaces can solve. Therefore, investigating how surface wrinkles vary and are implemented across biological systems is key...
Buildings
Natural ventilation associated with a mechanical fan is a feasible strategy to enhance thermal ac... more Natural ventilation associated with a mechanical fan is a feasible strategy to enhance thermal acceptability in warm weather. The ASHRAE-55 provides the increase for operative temperature proportional to the increase in air speed while maintaining thermal comfort. Conversely, the range of informed values is limited and little guidance for mechanical fans is provided. This work explores the relationship between operative temperature and air speed produced by ceiling fans, and the effectiveness to deliver thermal comfort for a wider range of values. The research method comprises transient computer fluid dynamics simulations coupled with a thermal sensation model and is divided into two stages: a calibration exercise and a parametrical investigation. Three matrices are presented for a range of operative temperatures (21.0–36.0 °C) and air speeds (0–2.5 m/s) for: Dynamic Thermal Sensation (DTS) (a computer-based seven-point index), Predicted Percentage of Dissatisfied, and potential Coo...
Sustainability
Improving indoor environment quality and making urban centres in tropical regions more sustainabl... more Improving indoor environment quality and making urban centres in tropical regions more sustainable has become a challenge for which computational models for the prediction of thermal sensation for naturally ventilated buildings (NVBs) have major role to play. This work performed analysis on thermal sensation for non-residential NVBs located in Brazilian tropical warm-humid climate and tested the effectiveness of suggested adaptive behaviours to mitigate warm thermal sensation. The research method utilized transient computational fluid dynamics models coupled with a dynamic model for human thermophysiology to predict thermal sensation. The calculated results were validated with comparison with benchmark values from questionnaires and from field measurements. The calculated results for dynamic thermal sensation (DTS) seven-point scale showed higher agreement with the thermal sensation vote than with the predicted mean vote. The test for the suggested adaptive behaviours considered red...
Building Simulation Conference proceedings
This paper presents four design charts (DC) to work as a simplified, easy-to-use and cost-effecti... more This paper presents four design charts (DC) to work as a simplified, easy-to-use and cost-effective tool to assist architects and building designers on sizing openings to deliver natural ventilation (NV) for cooling. The DC are derived from analytical techniques for four NV design systems based either on buoyancy-driven or wind-driven flow. The application of the DC is demonstrated to size NV openings for a bedroom in an apartment located in three Indian cities for two opening size scenarios: 'business as usual' (A); and 'necessary size' (B) to deliver the desired ventilation rates for cooling. The ventilation rates for cooling found with these DC are compared with outputs from computational fluid dynamics simulations. Findings show that for the earlier design stage the derived DC are effective tools. It is also found that the opening sizes used in scenario A do not deliver the desired NV rates for cooling, whilst the openings for scenario B must be sized separately for each city to be effective.
Building Simulation, 2019
Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts o... more Direct evaporative cooling (DEC) is one of the most commonly used cooling systems in many parts of the world with mainly hot and dry climatic conditions. Various simulation-based studies have been conducted to explore the potential of direct evaporative cooling in buildings. However, current dynamic thermal simulation tools use a simplified on/off control approach and do not allow modelling of situations where advanced algorithms are used in controlling DEC units. This paper couples EnergyPlus with Dymola® to simulate and assess the benefits of sophisticated control strategies for DEC units in mixed-mode buildings. This is a novel simulation approach for investigating control of DEC units in buildings that provides great flexibility for investigating future advanced control algorithms. The simulated results suggested that using the proposed sophisticated control algorithms for DEC units it is possible to achieve energy savings up to 35% compared to the base-case scenario and achieve...
This paper aims to identify the potential of natural ventilation for cooling a representative two... more This paper aims to identify the potential of natural ventilation for cooling a representative twobedroom residential apartment layout in India. India faces an unprecedented demand for residences and must reduce energy consumption associated with air-conditioning. Three significant climates and cities in India are investigated in this paper. The potential to extend the hours of the year for which thermal comfort is achievable using natural ventilation strategies is tested. This potential is identified by employing analytical methods to design and size ventilation capacity. Five natural ventilation design strategies are used over several scenarios varying window free area and ceiling fan speed. Indoor temperature setpoints are based on the India Model for Adaptive Comfort. Results are given as percentage of hours of the year for which natural ventilation is capable to remove calculated heat gains. Percentages of hours are divided into day-time and night-time. Findings show that the co...
The purpose of this study consists of verifying the efficiency of building facade materials and n... more The purpose of this study consists of verifying the efficiency of building facade materials and natural ventilation systems to control internal temperature in the office buildings of the city of Sao Paulo. It is assumed that such systems must achieve office environment users' standard comfort levels to be considered efficient, as well as maintain a reasonable relation between cost of implementation / performance, contribute to energy consumption reduction by minimizing the use of artificial air cooling systems and be easily operated by users and/or autonomous systems. For that, heat changes between building envelope, external environment and heating produced by internal environment occupants and/or equipment investigations were carried out with the objective of verifying in which period of the year optimum comfort levels can be reached through the means of natural ventilation, mechanical ventilation or cooling systems and how much energy has to be consumed with each alternative....
Journal of Urban Technology and Sustainability
O objetivo deste trabalho é avaliar a viabilidade financeira para instalação de um sistema fotovo... more O objetivo deste trabalho é avaliar a viabilidade financeira para instalação de um sistema fotovoltaico em uma residência unifamiliar localizada na região oeste da cidade de São Paulo. A energia solar fotovoltaica é a energia elétrica obtida por meio da conversão direta da radiação solar em energia elétrica. Este tipo de energia vem se popularizando nos últimos anos especialmente após resolução normativa ANEEL 482/20012 que fundamenta as diretrizes da microgeração e da minigeração distribuída no Brasil. Esta resolução permite ao usuário residencial gerar sua própria energia elétrica, fornecendo o excedente à rede de distribuição, assim como consumi-la quando geração é inferior a produção. Os créditos e débitos são contabilizados no consumo de energia elétrica ativa, nunca com importâncias monetárias. A decisão pela aquisição deste sistema é formada por fatores como conhecimento da tecnologia, conscientização ambiental e custo do sistema que vem diminuindo muito nos últimos anos. Est...
This paper presents the results of an investigation focused on a scale for predicting the potenti... more This paper presents the results of an investigation focused on a scale for predicting the potential for naturally ventilate buildings in the urban environment. This scale is based on the Pearson r model of correlation coefficients between urban physical dimensions with the resulting wind-driven pressure coefficients (Cp). Numerical simulations using computational fluid dynamics (CFD) were performed to a large number of urban prototypes with simplified volumetric shape. These urban prototypes were originally based on ratios of actual urban areas. The systematic variation of the volumetric urban aspect ratio of these prototypes and the simulation for three wind directions allowed finding the relationship between the urban fabric and the ∆Cp. The range in the urban prototype shapes covered as many types of urban fabric as possible, from high to low density, from low building centres to downtown skyscraper areas. Eventually, two actual urban areas and buildings, the Cardiff University Cathays Campus, in Cardiff- Wales, and the Paulista Avenue, in Sao Paulo- Brazil, were also simulated and contrasted to the urban prototypes scale. A relationship was found between the urban aspect ratios and the ΔCp results. This was demonstrated by statistical methods using the data on the variables concerned, thus verifying the strength of the correlation between them. Strong correlation was found between the investigations into similar scenarios of the urban prototypes and the two case studies as regards both the aspect ratios and the ΔCp results. On the other hand, low correlation for the same variables was identified when contrasting dissimilar urban prototype scenarios. KEY WORDS urban environment; aspect ratio; wind pressure; cfd; k-e; and Cp.
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Papers by Luciano Caruggi