Energy research in airports: A review

The main function of an airport is to provide access to air transport both for passengers and cargo. The number of air operations over the past 20 years has increased rapidly, and this has led to a rise in the energy needs of airports to satisfy this demand. As a consequence, the cost of energy supply for airport managers has escalated. At the same time, global energy consumption has soared due to the needs of emerging countries like China and India, with the consequent environmental impact. This complex scenario of environmental and economic factors has made airport managers become aware of the need to reduce energy consumption as well as a more efficient use of it. The aim of this article is to analyze the main behaviors and energy trends at airports in more recent research, starting with the description of the main energy sources and consumers, the application of energy conservation and energy efficiency measures, the establishment of energy indicators and benchmarking between airports, as well as energy modeling and simulation

Phase change thermal energy storage for the thermal control of large thermally lightweight indoor spaces

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Energy storage using Phase Change Materials (PCMs) offers the advantage of higher heat capacity at specific temperature ranges, compared to single phase storage. Incorporating PCMs in lightweight buildings can therefore improve the thermal mass, and reduce indoor temperature fluctuations and energy demand. Large atrium buildings, such as Airport terminal spaces, are typically thermally lightweight structures, with large open indoor spaces, large glazed envelopes, high ceilings and non-uniform internal heat gains. The Heating, Ventilation and Air-Conditioning (HVAC) systems constitute a major portion of the overall energy demand of such buildings. This study presented a case study of the energy saving potential of three different PCM systems (PCM floor tiles, PCM glazed envelope and a retrofitted PCM-HX system) in an airport terminal space. A quasi-dynamic coupled TRNSYS®-FLUENT® simulation approach was used to evaluate the energy performance of each PCM system in the space. FLUENT® simulated the indoor air-flow and PCM, whilst TRNSYS® simulated the HVAC system. Two novel PCM models were developed in FLUENT® as part of this study. The first model improved the phase change conduction model by accounting for hysteresis and non-linear enthalpy-temperature relationships, and was developed using data from Differential Scanning Calorimetry tests. This model was validated with data obtained in a custom-built test cell with different ambient and internal conditions. The second model analysed the impact of radiation on the phase change behaviour. It was developed using data from spectrophotometry tests, and was validated with data from a custom-built PCM-glazed unit. These developed phase change models were found to improve the prediction errors with respect to conventional models, and together with the enthalpy-porosity model, they were used to simulate the performance of the PCM systems in the airport terminal for different operating conditions. This study generally portrayed the benefits and flexibility of using the coupled simulation approach in evaluating the building performance with PCMs, and showed that employing PCMs in large, open and thermally lightweight spaces can be beneficial, depending on the configuration and mode of operation of the PCM system. The simulation results showed that the relative energy performance of the PCM systems relies mainly on the type and control of the system, the night recharge strategy, the latent heat capacity of the system, and the internal heat gain schedules. Semi-active systems provide more control flexibility and better energy performance than passive systems, and for the case of the airport terminal, the annual energy demands can be reduced when night ventilation of the PCM systems is not employed. The semi-active PCM-HX-8mm configuration without night ventilation, produced the highest annual energy and CO2 emissions savings of 38% and 23%, respectively, relative to a displacement conditioning (DC) system without PCM systems.UK Engineering and Physical Sciences Research Counci

Responsive Architecture

This book is a collection of articles that have been published in the Special Issue “Responsive Architecture” of the MDPI journal Buildings. The eleven articles within cover various areas of sensitive architecture, including the design of packaging structures reacting to supporting components; structural efficiency of bent columns in indigenous houses; roof forms responsive to buildings depending on their resiliently transformed steel shell parts; creative design of building free shapes covered with transformed shells; artistic structural concepts of the architect and civil engineer; digitally designed airport terminal using wind analysis; rationalized shaping of sensitive curvilinear steel construction; interactive stories of responsive architecture; transformed shell roof constructions as the main determinant in the creative shaping of buildings without shapes that are sensitive to man-made and natural environments; thermally sensitive performances of a special shielding envelope on balconies; quantification of generality and adaptability of building layout using the SAGA method; and influence of initial conditions on the simulation of the transient temperature field inside a wall

Numerical Wind Resource Assessment in Urban Environments

This thesis leads to a framework for micrositing, the process through which the specific location for mounting micro wind turbines in urban environments is determined. It can be used as a guidance on how to model an area of interest, find the optimum location for micro wind turbines installation and calculate the annual energy production, commenting on the accuracy that can be expected from the results. Essentially, it is composed of three parts, each one deals with different set of tasks associated with model development and simulation. The first part investigates the computational practices to the fields of turbulence in urban environments implemented in the open-source CFD library OpenFOAM. It examines the performance of a turbulence model, known as DES, which has not been previously used for external flows in complex urban environments and concludes that this approach offers improved robustness and accuracy over a range of wind conditions. It offers improved prediction of flows in wake regions compared to RANS methods and is less computationally demanding than full LES approaches. The validity of DES implementation is tested using data sets derived from both wind tunnel experiments and field measurements. In the second part, a procedure is developed to identify the optimum location for mounting wind turbines, based on the spatial variations in mean annual wind speed and the corresponding annual energy production (AEP). The procedure utilizes one year of measured wind data for one site to extrapolate (using the `Wind Atlas Methodology') the annual wind speed at the site of interest. Then combining the climate data with the CFD results and the power characteristics of the micro wind turbines, it estimates the mean wind speed and the annual energy yield. Essentially, this methodology leads to the formation of three dimensional fields of the average annual wind speed and the AEP (3d wind maps), which will enable identification of the effects of the complex urban topography on the wind flow, and the potential locations for micro wind turbines installation. The third part examines the accuracy that can be expected from the annual energy production estimation techniques and provides guidelines on the calculations. In particular, it investigates the validity of the standard power curves for the site-specific air density and evaluates their effect on the annual energy production estimations. Differences of the order of 10-3 between the default and the site specific mean air density (ρ), do not change substantially the energy production. However, for higher discrepancies of the order of 10-2 the power output can differ more than 10%. Turbulence affects the wind energy in two ways: through power performance impacts and through effects on turbine loads and fatigue. In the operational range of each turbine, TI increases the output at low wind speeds, while in the transition region to rated power it decreases the power output. In the context of this study, the DES approach was implemented to examine the flow at the De Montfort university campus in Leicester. The 3d wind maps for the mean wind speed and the annual energy production were developed and the optimum locations for micro wind turbines installation were identified. Although the rooftops of the higher buildings have mostly the potential for wind energy applications, the effect of the urban topography on the wind potential is not always apparent. Lower building can occasionally have higher potential for micro wind turbines installation than taller and roofs of the same height and close each other may differ substantially in their predicted energy output. Using the field measurements by two 3d ultrasonic anemometers placed in the campus, the site specific air density and turbulence intensity were considered to correct the energy yield estimations and evaluate their effect on the results

A simplified multi-zone model for determining the placement of bio-defense sensors in large buildings

Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, 2008.Includes bibliographical references (leaves 110-112).The anthrax mailings of 2001 increased public and government awareness to the threat of bio-terrorism. Particularly vulnerable to a bio-terrorist event are large indoor facilities such as convention centers, office buildings, transportation centers, and sports arenas with their high population densities and limited physical security. Under heightened threat levels deploying bio-aerosol sensors inside these facilities provides added protection to the occupants. The challenge is determining the number and placement of sensors needed to guarantee the detection of a release inside a particular building. The methodology proposed here aims to simplify the analysis of contamination transport within buildings and provide first-order sensing requirements for dose dependant sensors in large facilities. A reduced-order model is developed that allows buildings to be subdivided into larger sections while maintaining a higher degree of accuracy than building analysis models with the same level of granularity. The problem is formulated as a network model with the nodes representing possible sensor locations and the path lengths equal to the reduction in dose as a contaminant travels between sensor locations. Techniques borrowed from network theory are then used to determine the minimum cost set of sensors that provides full building coverage. The reduced-order model estimates sensing requirements in hours or days for problems that would take months to analyze with fine grained multi-zone models and that are too large to be considered with computational fluid dynamics. Models of an office building, a convention center, and an airport terminal are constructed and their underlying network graph is employed to understand how the structure of the indoor environment affects the placement of sensors.(cont.) Additionally, the equations derived to formulate the network model are used to quantify the optimal tradeoff between sensor sensitivity and cost as a function of building parameters. Future efforts will continue on this path, focusing on how easily discernible building properties such as size, HVAC layout, and air exchange rates can be used to predict the sensing requirements in large indoor spaces.by Scott B. Van Broekhoven.S.M

Energy aspects and ventilation of food retail buildings

Worldwide the food system is responsible for 33% of greenhouse gas emissions. It is estimated that by 2050, the total food production should be 70% more than current food production levels. In the UK, food chain is responsible for around 18% of final energy use and 20% of GHG emissions. Estimates indicate that energy savings of the order of 50% are achievable in food chains by appropriate technology changes in food production, processing, packaging, transportation, and consumption. Ventilation and infiltration account for a significant percentage of the energy use in food retail (supermarkets) and catering facilities such as restaurants and drink outlets. In addition, environmental conditions to maintain indoor air quality and comfort for the users with minimum energy use for such buildings are of primary importance for the business owners and designers. In particular, supermarkets and restaurants present design and operational challenges because the heating ventilation and air-conditioning system has some unique and diverse conditions that it must handle. This paper presents current information on energy use in food retail and catering facilities and continues by focusing on the role of ventilation strategies in food retail supermarkets. It presents the results of current studies in the UK where operational low carbon supermarkets are predicted to save 66% of CO2 emissions compared to a base case store. It shows that low energy ventilation strategies ranging from improved envelope air-tightness, natural ventilation components, reduction of specific fan power, ventilative cooling, novel refrigeration systems using CO2 combined with ventilation heat recovery and storage with phase change materials can lead to significant savings with attractive investment return

Low-income housing layouts under socio-architectural complexities: A parametric study for sustainable slum rehabilitation

Lack of sustainable slum redevelopment guidelines in India is a policy gap that needs immediate attention. A rational design and planning route is necessary to ensure sustainability of the upcoming low-income (LIG) housing stocks. In this study, we performed a cross-sectional evaluation of LIG housing layouts through a socio-architectural and site-based wind-flow analysis route. We hypothesise that a better indoor environment in the LIG housing can be achieved through a better wind driven natural-ventilation in the living spaces, which is a function of the housing layout. Specific objectives of this study were: i) to investigate the influence of socio-architectural and geometric parameters on the LIG housing layouts; ii) to examine the effect of site-wind flow on LIG housing layouts using CFD simulations. BDD chawls of Mumbai were adopted as the case study. Results show that the current form of the LIG houses had a poor indoor environment and social interaction spaces, while the hypothesised iterated layout ‘Form A’ performed better in all the socio-architectural and wind-flow metrics that can promote relatively better quality of life. This study is a first-step approach for the development of regulatory guidelines in LIG housing design that is coherent to the context of the space.Ministry of Human Resource Development, Government of India Commonwealth Scholarship Commission Cambridge Trus

Study of thunderstorm wind outflows and proposition of mean wind profiles

The impact of thunderstorm (TS) winds on the built environment has been extensively reported in recent years showing that current wind standards do not properly represent all types of extreme wind events. This document discusses the characteristics of TS winds in depth, focusing on existing vertical full-scale measurements, modeling approaches and their occurrence worldwide. Firstly, the development of the downburst research worldwide is reviewed and, due to Brazil’s vulnerability to this type of event, reported cases in national news and scientific literature are investigated. This study showed that most of Brazil is vulnerable to downbursts, having the Amazon region the larger amount of occurrences and the Southern states the most susceptible for extreme winds generated by TS outflows or simply downbursts. The Southeastern states are also prone to extreme downburst occurrence. Northeast and central north states present downburst events with lower intensity, which are caused mostly by isolated thunderstorms. Modeling techniques are commonly adopted to study the effects of these events on the built environment. A systematic review of 122 publications on downburst modeling identified four main clusters of alternative approaches to simulating these events: analytical modeling, experimental laboratory simulations, computer fluid dynamics (CFD) and data-driven models. An analytical method is proposed to describe the mean wind speed profiles at their maximum stage based on full-scale measurements considering the storm organization, time averaging and terrain categories. The proposed fitted curve profile functions are valid only for the original measured average intervals. Results showed that most of the proposed fitted curve profile functions had a "nose-like" shape, highly defined by the terrain roughness, with peak velocities typically observed at lower levels in TS winds – between 50 and 250 meters – allowing the profile fitting by a third‐degree polynomial function, instead of the traditional power law function as adopted for synoptic winds. Seventeen profiles originated from full-scale measurements were selected and carefully analyzed. However, in order to propose a practical application that can be coupled with a general extreme wind climatology, only seven fitted curve profile functions were taken for further analysis. Six out of seven fitted curve profiles demonstrated good adherence to Ponte Junior (2005) model and the TS wind profile proposed by the international code ISO 4354. These proposed profiles were further analyzed along with the typical NBR-6123 boundary layer velocity profiles. For Terrain Category II, the fitted curve profile function based on the maximum profile of Gunter and Schroeder (2015) "PEP Event" for 1-min time averaging presented the most conservative case at all elevations. For Terrain Category III, results were mixed, but the fitted curve profile function based on the maximum profile measured by Lombardo et al. (2014) "03-Aug-2010 Event" presented maximum values at lower levels for 3-s time averaging and is therefore considered the maximum profile for this terrain category. Finally, for Category IV, it is suggested to use as reference the fitted curve profile based on the maximum profile of Zhang *et al.* (2019) "15:01 Meas.", since this is a more realistic TS wind profile dataset for 30-s time averaging due to the particular effects of the terrain on that specific measurement.O impacto dos ventos gerados por tempestades (TS) no ambiente construído tem sido amplamente relatado nos últimos anos, revelando que as normas de vento atuais não representam adequadamente todos os tipos de ventos extremos. Neste documento se discute em profundidade as características dos ventos TS, com foco em medições verticais de escala real, abordagens de modelagem e sua ocorrência no mundo. Primeiramente, é revisado o desenvolvimento mundial das pesquisas sobre downbursts e, devido à vulnerabilidade do Brasil a esse tipo de evento, é feita uma investigação de casos relatados em notícias e literatura científica. Este estudo mostrou que a maior parte do Brasil é extremamente vulnerável a downbursts, tendo a região Amazônica o maior número de ocorrências e os estados da região Sul os mais suscetíveis a ventos extremos gerados por tormentas TS ou simplesmente downbursts. Os estados do Sudeste são também propensos à ocorrência de downbursts severos. Os estados do Nordeste e Centro-Norte apresentam eventos de menor intensidade, causados principalmente por tempestades isoladas. Técnicas de modelagem são comumente adotadas para estudar os efeitos desses eventos no ambiente construído. Uma revisão sistemática de 122 publicações sobre modelagem de downbursts identificou quatro grupos principais de abordagens para simular esses eventos: modelos analíticos, simulações experimentais em laboratório, dinâmica de fluidos computacional (CFD) e modelos baseados em dados. Um método analítico é proposto para descrever os perfis médios de velocidade de vento em seu estágio máximo com base em medições em escala real, considerando-se organização da tempestade, intervalo de tempo e categorias de terreno. As funções de perfil de curva ajustada propostas são válidas apenas para os intervalos de tempo medidos originais. Os resultados mostraram que a maioria das funções propostas de perfis de curvas ajustadas tinham forma de "nariz", fortemente definida pela rugosidade do terreno e com velocidades de pico tipicamente observadas em níveis mais baixos em ventos TS – entre 50 e 250 metros – permitindo o ajuste do perfil por uma função polinomial de terceiro grau, em vez da função de potência tradicional, como utilizado para ventos sinóticos. Dezessete perfis oriundos de medições reais foram selecionados e analisados minuciosamente. Porém, para possibilitar a proposição de uma aplicação prática capaz de incorporar resultados de climatologias gerais de ventos extremos TS, somente sete curvas ajustadas foram levadas adiante para análise. Seis dos sete perfis ajustados demonstraram boa aderência ao modelo de Ponte Junior (2005) e ao perfil de vento TS proposto pelo código internacional ISO 4354. Esses perfis propostos foram posteriormente analisados juntamente com os perfis de velocidade de camada limite típicos da NBR-6123. Para a categoria de terreno II, a função do perfil ajustada com base nos valores máximos obtidos por Gunter e Schroeder (2015) no "PEP Event" para intervalo de tempo de 1-min apresentou o caso mais conservador em todas as elevações. Para a categoria de terreno III, os resultados foram mistos, mas considerou-se como evento extremo o perfil ajustado baseado no evento extremo de “03-ago-2010" de Lombardo et al. (2014) para o intervalo de média de tempo de 3-s. Finalmente, para a Categoria IV, sugere-se utilizar como referência o perfil de curva ajustado ao evento extremo registrado por Zhang et al. (2019) "15:01 Meas.", uma vez que o perfil de vento TS resultante é mais realista para média de tempo de 30-s devido aos efeitos do terreno específicos deste caso

Field Measurements of Wind-Driven Rain on Mid - and High - Rise Buildings in Two Canadian Regions

Wind-driven rain (WDR) is an important boundary condition for the study of the hygrothermal behaviour and durability of building envelopes. Understanding the WDR characteristics is important for establishing designs that minimize the moisture related issues. The objectives of this study are to generate a unique set of measurements to characterize the WDR distribution on mid- and high-rise buildings for different Canadian climatic regions, to provide data for validating CFD models and to evaluate the accuracy of existing semi-empirical methods used for quantifying WDR loads on building façades. Three buildings located in two Canadian cities (i.e., McLeod House in Fredericton; HB and FB Building in Montreal) have been instrumented with equipment to simultaneously record local weather data of wind speed, wind direction, temperature, relative humidity, horizontal rainfall, and WDR loads on building façades. Onsite data, collected for fourteen months from McLeod House, fifteen months from HB Building, and twelve months from FB Building, has been used for analysis. The historical and onsite wind and rain conditions, spatial distribution of wind-driven rain on façades in terms of catch ratios and wall factors, and comparisons between measured and predicted wind-driven rain using the semi-empirical models are reported for the monitoring periods. The analysis of field measurements shows that catch ratios vary with rain events with higher values at the corners and edges of the façades. Typically catch ratios are higher at the top of the facades and decrease towards the bottom. The catch ratios are higher for the thirteen story high-rise building compared to the four and seven story mid-rise buildings at the same height below the roofline. Catch ratios are higher when approaching wind is normal to the façade and values increase with the increase of wind speed. Discrepancies between the ISO standard suggested wall factors and wall factors calculated based on measurements are observed for all three test buildings. It is found that the wall factors vary along both the building height and across the building width, while the ISO standard only suggests two values along the building height with no change across the building width. The ISO semi-empirical model overestimates the WDR at all monitored façade locations on McLeod House and HB Building, and 83% of the monitored façade locations on FB Building. The ASHRAE 160 model overestimates the WDR amount largely for most of the monitored façade locations of the test buildings. The discrepancies between measurements and predictions using semi-empirical models are due to the lack of variation of wall factors across building façade suggested in the standards and limited number of building geometries. The errors associated with WDR measurements vary with rain events with the maximum error contributed by adhesion-water-evaporation, however, the total amount of error is small as compared to WDR amount. To improve the semi-empirical models for estimating WDR on façade, wall factors based on field measurements on buildings with a wider range of building geometries and at more façade locations are needed

Introduction to the LaRC central scientific computing complex

The computers and associated equipment that make up the Central Scientific Computing Complex of the Langley Research Center are briefly described. The electronic networks that provide access to the various components of the complex and a number of areas that can be used by Langley and contractors staff for special applications (scientific visualization, image processing, software engineering, and grid generation) are also described. Flight simulation facilities that use the central computers are described. Management of the complex, procedures for its use, and available services and resources are discussed. This document is intended for new users of the complex, for current users who wish to keep appraised of changes, and for visitors who need to understand the role of central scientific computers at Langley