Matthias Berger

Cellular Automata-based Anthropogenic Heat Simulation

Abstract Cellular automata (CA) models have been for several years, employed to describe urban phenomena like growth of human settlements, changes in land use and, more recently, dispersion of air pollutants. We propose to adapt CA to study the dispersion of anthropogenic heat emissions on the micro scale. Three dimensional cubic CA with a constant cell size of 0.15 m have been implemented. Simulations suggest an improvement in processing speed compared to conventional computational fluid dynamics (CFD) models, which are limited in scale and yet incapable of solving simulations on local or larger scale. Instead of solving the Navier- Stokes equations, as in CFD, only temperature and heat differences for the CA are modeled. Radiation, convection and turbulence have been parameterized according to scale. This CA- based approach can be combined with an agent-based traffic simulation to analyse the effect of driving behavior and other microscopic factors on urban heat.

CFD Post-processing in Unity3D

In architecture and urban design, urban climate on is a strong design criterion for outdoor thermal comfort and buildings energy performance. Evaluating the effect of buildings on the local climate and vice versa is done by computational fluid dynamics (CFD) methods. The results from CFD are typically visualized through post-processing software closely related to pre-processing and simulation software. The built-in functions are made for engineers and thus, it lacks user-friendliness for real-time exploration of results for architects. To bridge the gap between architect and engineer we propose visualizations based on game engine technology. This paper demonstrates the implementation of CFD to Unity3D conversion and weather data visualization.

CityHeat: visualizing cellular automata-based traffic heat in Unity3D

Cellular Automata (CA) based simulation can be employed to understand traffic heat emission at micro scale level. Simulation space is divided into cubes of various sizes that encapsulate temperature within the cubes volume at different time stamps. Using this simulation result, we introduce CityHeat, a visualization tool to observe traffic heat distribution developed using Unity3D. Game engine is employed as a tool to reach interdisciplinary stakeholder groups that might not be coming from engineering background to understand the domain problem.

Value Lab Asia: A Space for Physical and Virtual Interdisciplinary Research and Collaboration

Many contemporary research tasks require complex decision making and interdisciplinary collaboration among different groups of experts and stakeholders. Nowhere is this more apparent than in the planning and design of future cities - rapidly growing cities where the development and allocation of energy, housing, transportation and other scarce resources requires the active participation of architects, urban planners, government stakeholders and private citizens. In this paper, we show how recent advances in display technology can facilitate such collaboration and create new opportunities for participatory urban planning. We introduce the Value Lab Asia as a model for collaborative planning and value creation, and show how a multi-screen display management framework called the Tool Library integrates the laboratorys physical and software infrastructure with the planning process.

CAD integrated workflow with urban simulation-design loop process

The urban space nowadays is considered as an aggregate of large amount of complex characteristics. Information collected by means of urban big data approaches play a crucial role in how to understand, interpret and model urban environments. Simulation models are the best solution for architects, urban planners and designers to integrate various information about urban complexity into the design process. The connection between several simulation approaches within one user interface is still a big challenge to make the design process faster, more accurate and visually convenient. The interface would be involved in the modelling process, pre-processing, simulation, post-processing and visualisation. A CAD integrated user interface is proposed where all these particular components are embedded into one system. The whole process would be based on a workflow loop whereby each component will be depending on the previous cycle. As a case-study of such a principle we establish an extendable modelling and simulation platform connected to a user through the game-engine Unity3D in order to achieve a robust interactive environment. The model platform operates with real urban conditions of an existing part of the city of Singapore and simulates the distribution of traffic’s heat within the investigated environment. Based on the simulation results the user can configure more proper spatial scenarios within the urban plan in different variations. The proposed system would help architects and urban planners to enhance their decision repertoire during the design phase and allows them taking into account more complex information about the urban entirety. The result of the research is therefore a computational decision-making tool with enhanced visual output.

Game Engines for Urban Exploration: Bridging Science Narrative for Broader Participants

One aspect of playing is exploration. A playable city could therefore be regarded as an explorable city. In recent years, a growing number of urban exploration tools have been developed, empowered by the technology of game engines. Traditionally, game engines have been used to create virtual environments for entertainment and enable the user to explore. We seek to apply game engines in urban planning beyond the visualization of buildings, trees, traffic, or people in the city. It can become a tool for a multidisciplinary approach that involves engineers, scientists, architects, planners, and even the citizens themselves. Those kind of mixed stakeholders have quite diverse needs, which all can be addressed by game engines in an easy way. In this chapter, we look toward bridging the seen and unseen elements in a collaborative game environment. One of the less visible elements in urban environment involves the urban microclimate: heat emission, wind flows, and outdoor thermal comfort. These unseen scientific elements have become a narrative on their own on top of the urban exploration. If they are to be presented in the traditional way of scientific visualization, the connection to the built environment would be difficult to understand for many kinds of stakeholders, especially the nonscientists. Hence, we utilize the power of the Unity3D game engine to show the potential of collaborative and explorative virtual environments: a bottom-up citizen design science within the narrative of exploration and urban science data.

The Manifold Challenges for Modeling the Urban Heat Island

Abstract Urban heat islands (UHIs) can have negative effects on cities. Under tropical climate and for large and high-dense mega cities like Singapore the elevated temperature levels yield to higher energy consumption for cooling, reduced outdoor thermal comfort, and a lowered quality of urban living in general. While modeling and simulation of UHIs has been done successfully for the temperate zone and cities of either dominantly flat roof-scape (i.e. in Europe) or repetitive urban layout (in the U.S.), the same approach cannot be applied to Singapore. Three-dimensional cellular automata (3D-CA) are here proposed as means to model the manifold vertical features, which are not sufficiently taken into account with current state-of-the-art methods: the heterogeneous high-rise landscape and convection as a major heat rejection mechanism. As we demonstrate 3D-CA enable a new approach of UHI modeling where traditional urban microclimate models fail and computational fluid dynamics are not applicable due to the large scale.

Development of a new urban heat island modeling tool: Kent Vale case study.

Abstract Urban heat island is intensified by anthropogenic activities and heat in conjunction with the built-up urban area, which absorbs more solar radiation during daytime and releases more heat during nighttime than rural areas. Air cooling systems in Singapore, as one of the anthropogenic heat sources, reject heat into the vicinity and consequently affect urban microclimate. In this paper, a new urban heat island modeling tool is developed to simulate stack effect of split type air-conditioners on high rise buildings and solar radiation induced thermal environment. By coupling the Computational Fluid Dynamics (CFD) program with the solar radiation model and perform parallel computing of conjugate heat transfer, the tool ensures both accuracy and efficiency in simulating air temperature and air relative humidity. The annual cycle of sun pathway in Singapore is well simulated and by decreasing the absorptivity or increasing the reflectivity and thermal conductivity of the buildings, the thermal environment around buildings could be improved.

Energy recovery from LNG regasification for space cooling-technical and economic feasibility study for Singapore

This paper investigates three scenarios for (LNG) Liquefied natural gas driven district cooling grids in terms of technological and economic feasibility. The scenarios consist of commercial, residential, and low temperature industrial cooling and their combinations. These scenarios achieve tremendous energy savings in comparison with conventional mechanical cooling. The free cooling potential in Singapore is calculated to Singapore Dollars (SGD) 800.75 million p.a. depending on the scenario, based on a regasification heat demand of 1009 kJ/kg of LNG with current terminal capacity of 3.5 Million Tonnes per annum (MTPA). In addition to the economic benefit, there is also an environmental benefit of 655.57 Million kg of CO2 e/a (CO2 equivalent) through Greenhouse gas (GHG) emissions reduction by free cooling utilization. The terminals capacity has increased to 6 MTPA by the end of 2014.

Energy Scenario Modelling in Developing Countries: A Collaborative Computer-based Tool Using Tangible Interfaces

Developing countries face different challenges for future electrical energy planning than developed countries. In particular, rural areas suffer from lack of energy supply, which is due to missing transmission infrastructure, influence of foreign players, and capitalization of energy production resources through export. In this paper, we highlight this situation by the case of Ethiopia, one of the least developed countries worldwide. So far, Ethiopia’s energy strategy is mainly based on hydropower, with major projects under construction. However, these projects are unlikely to support rural areas, and in addition have already sparked international controversy due to the substantial ecological impact. In order to obtain a better understanding of which alternative pathways may be feasible, we offer a new planning methodology based on an interactive and collaborative computer-based tool. The tool allows the exploration of different scenarios that include alternative energy sources such as wind power and photovoltaics. Our tool addresses the gap between current policy debates that will shape the development path of the country and existing energy modeling tools. Most existing tools are sophisticated but seem less adequate for developing countries in terms of scope and basic assumptions. By addressing these shortcomings, we present a tool that takes the specific properties of emerging energy markets into account and allows exploring the impact of various policy decisions in a collaborative way without assuming the presence of perfect markets or ubiquitous infrastructure. The tool does not require expert knowledge and can be made available easily to decision-makers, stakeholders, and the public as we demonstrated at the Addis2050 conference in Addis Ababa in 2012.