Spring 2015 Research and Coursework CONTENTS: 1. Real-Time Computational Fluid Dynamics Visulization 2. Computational Fluid Dynamics: A method For Building Simulation 3. Urban Mobility Analysis in Early stages of Masterplanning 4. Thermo-Active Surfaces
Nada Tarkhan Master in Design Studies Candidate- Energy and Environments Harvard University, Graduate School of Design
Augmenting Reality: Real Time (Air Flow) Fluid visualization Quantitative Aesthetics: Computational Fluid Dynamics
This project sets out to investigate the visualization of airflow based on computational fluid dynamics methods (CFD). The aim was to augment a sense, or rather bring forth an experience of airflow that is both highly visual and inaccessible to our senses. CFD uses numerical methods to both analyze and predict air flows in a steady state condition. Objects and people in a field disturb flow and create collisions and flow convergence. Energy driven designs use CFD as a tool to understand air and fluid behavior in space. Such methods are slowly materializing in the design discipline but are being deterred due to complexity and extensive computing time. These visualizations are also static and isolate themselves from the physical realm of interaction. Hence, the question of real-time CFD visualization is a great challenge in itself. Our intention for this project was to bring forth intrinsic qualities of a CFD model and manifest them in three dimensional space such that they have a sensorial dimension. Instead of using complex simulation engines, we tended towards coding to have access to the root equations governing fluid flow.
Focusing on the Lattice Boltzmann Methods (LBM) for fluid simulations, we aimed to bridge computational phenomena with real-time interaction and simulation. The (LBM) maps these particle collisions on a lattice mesh that can respond to movements or alterations within its defined boundaries which facilitates real time response. Using these equations and coding libraries enabled us to have real-time CFD visualizations on a 2D controlled grid. The aspect of human interaction formed the next layer to the code which was achieved by using Microsoft Kinect. For the entire visualization to be experienced in an expanded dimension, the output was projected onto a carefully designed installation of light fabric. Allowing the entire setup to be defined by dimensions of a room gave the installation a strong connection to the physical space.
Computational Fluid Dynamics: A method For Building Simulation Building Simulation
This project sets out to investigate the redesign of housing units to achieve a reduction in energy consumption and increased ventilation hours annually. The main method used is based on computational fluid dynamics for air flow assesment. Buoyancy ventilation is the main focus of this study. A solar chimney is incorporated in the design to flush out excess heat and ensure a more pleasant temperature indoors. By knowing the exact hours where temperatures are satisfactory, natural ventilation can be used and cooling loads are reduced drastically. Solar Analysis was also carried out to investigate the impact of the arrangement of units. Located in ABu Dhabi where solar radiation is very high, it was important to study shadow ranges and investigate seasonal patterns.
Solar Analysis
Shadow ranges
Thermal- Air flow patterns
The spacing proposed intends to both allow for constant air flow, and provide shading. The existing case creates high wind speeds due to the narrow spacing. A better scheme could lie between the 2 spacing iterations where there could be a possibility for open shaded spaces
CFD MODELING : FINAL DESIGN: Stack with opening at the top Double roof Despite the double roof, the radiant energy gain from the roof is quite substantial. This puts the top units at higher temperatures than lower units. However, the overall scheme here can be seen in operation. The indoor environment experiences temperatures within the comfort range. The vector arrows and speed mappings indicate a suction force in the chimney. At each floor the air can be seen flowing from the windows and out through the atrium. The thermal distribution in the building indicates that the top floor is the hottest as it is exposed to the most solar radiation.
Urban Mobility Analysis in Early stages of Masterplanning Environment, Economics, Enterprise
This project set out to investigate the use of urban mobility analysis tools to enhance the design of an urban livelihood at an early stage in design. The project is the Pittsburgh Technology center. The aim was to assess the impact of different mixes and bridge the outcomes with real estate decisions. UMI (Urban Modeling Interface) is an urban modeling software that was used to model the walkability and bikeability scores of the site. As well as this, Design builder was used to calculate the energy consumption per building use. The three stages of simulation are identified below: a. Mobility Studies: Using UMI to identify walkability and bikeability scores in the base case and two improved design scenarios. This was done by enhancing the road and pedestrian networks as well as adding amenities. b. Carbon Emissions: This analysis was done to further understand the building massing and its emissions. Each building in the PTC was simulated and the results were compared per square foot of each building type (residential, mixed use, office). c. Energy Use Intensity (EUI): This was done in hope of guiding the design of the building envelopes. The energy consumption per building type was calculated and normalized to evaluate the total mix energy consumption per foot in each design iteration. A set of design enhancements were proposed with regards to the building to wall ratio, lighting controls and shading strategies.
Thermo-Active Surfaces Designed Porous Media Using the potentials of thermo-active surfaces, this project aims to design a surface that could be used to cool a building. The surface is designed to have a large surface area as well as be composed of a material that would retain this coolness. By doing this radiative pre cooling could be possible. Through a series of tests and experiments, many porosities were investigated to optimize flow rate, cooling capacity and surface geometry.
SURFACE LOCATION
RADIATIVE COOLING
PRE-COOLING THROUGH SCREENS
Flow rate experiment using flow finder Visualizing Flow from cooled surface: Schlieren Experiment PROGRAM LOCATION
TOP ATRIUM TO DRAW AIR IN
Fan location
Thermo-active surface
FLOOR PLATES STEP BACK Sealed wooden
OUTDOOR GARDEN Flow finder