Mechanical Engineering Commons^™

Energy Efficient Renovations Of Storm Damaged Residences - Florida Case Studies, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

Storm-damaged homes offer the opportunity for repairs that reduce energy use, improve comfort and enhance resistance to future storms. Case studies of four Florida homes damaged in the summer of 2004 were documented to show the costs and benefits of various retrofit strategies. All four homes required roof replacement and each took advantage of roof cladding with higher reflectance than the original, a proven means of reducing cooling energy use. Two of the case studies included improvements to attic insulation, tightening of the envelope and/or duct system and improved efficiency equipment and lighting. Energy savings attributable to storm repairs were …

Photovoltaic Use In A Disaster: Mitigation Verses Response, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Natural disasters can happen at any time destroying lives, homes, businesses and the natural environment. In their path they leave many people without medical services, potable water, electrical services and communication for long periods of time. A disaster can be a minor or major incident impacting the people that survive its effect. We all become aware of the destruction caused by major hurricanes such as Katrina leaving several hundred-thousand people homeless and the resources needed to respond to save lives and restore property. In the midst of these extraordinary complications, emergency management teams, medical personnel, the military, and countless public …

Ifc To Contram Translator, Florida Solar Energy Center, Mangesh Basarkar

FSEC Energy Research Center®

Building security issues are of serious concern in the industry today. This paper will describe the design, development and testing of a software tool that can be effectively used to translate three dimensional building data sets of geometry, materials and HVAC components into an input file for the airflow and contaminant concentration simulation program CONTAM. The objective of the exercise is to allow for shorter turnaround time in evaluating IAQ strategies and building security related issues.

The software tool, 'fsIFCCTM', has been successfully tested to translate 3-D building elements like spaces, walls, doors, windows, and HVAC components like ducts, duct …

Improved Specifications For Federally Procured Ruggedized Manufactured Homes For Disaster Relief In Hot/Humid Climates, Florida Solar Energy Center, Stephanie Thomas-Rees

FSEC Energy Research Center®

The Federal Emergency Management Agency (FEMA) uses ruggedized manufactured homes to provide short term housing solutions during the repair and rebuilding phase after a natural disaster.

Federally procured manufactured homes are currently constructed in accordance with the Housing and Urban Development's (HUD) manufactured housing standards and typically built to the minimum code requirements. These homes can consume more energy than their site built comparatives and use materials and mechanical systems that can potentially contribute to poor indoor quality and low durability. Two improved specifications are presented in this report to enhance energy efficiency, sustainability, indoor air quality and provide back …

How Much Energy Are We Using? Potential Of Residential Energy Demand Feedback Devices, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Past studies of providing instantaneous feedback on household electrical demand show promise to reduce energy consumption by 10-15%. This paper surveys past research and describes a pilot evaluation of two low cost monitoring systems in case study homes. We also develop an evaluation protocol to use such devices to determine the relative energy intensity of various energy end uses. An identified advantage of the technology is that it provides better guidance on profitable areas to reduce household electrical demand-many of which are often unexpected. Moreover, our case studies showed that use of targeted power strips and occupancy-based controls can significantly …

The Energy Policy Pyramid - A Hierarchal Tool For Decision Makers, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

Policies of dealing with energy programs are often misdirected. Decision makers jump first to fuel substitution to either lower emissions or counter fuel price escalation. When it comes to both return on short-term economic investment and long-term sustainability for the economy and environment, there is a clear hierarchy. This paper presents the hierarchy as The Energy Policy Pyramid©.

Cooling Performance Assessment Of Building America Homes, Florida Solar Energy Center, Dave Chasar

FSEC Energy Research Center®

Long-term monitoring of building energy use and environmental conditions has been a strong component of FSEC research since the 1980s. Fully-automated data collection, verification, archiving and management ensure accurate logging of large amounts of data simultaneously from numerous field sites prior to being made available for analysis and display via the internet. Homes are typically monitored using 15 to 50 channels of data to measure indoor and outdoor environmental conditions and energy use of heating, cooling, water heating, whole house, and other points (e.g. Solar PV or Solar DHW) if needed.

Energy performance in many Building America homes has been …

Energy Performance Aspects Of A Florida Green Roof, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Previous green roof studies have found that planted roofs significantly reduce roof temperatures and roof heat flux, and simulations indicate cooling load reductions of up to 25%. This monitored study evaluates summer and winter energy performance aspects of a green roof on a central Florida university building addition that was completed in 2005.

Analysis of 2005 summer data indicates significantly lower peak roof surface temperatures for the green roof compared with the conventional roof and a significant shift in when the peak temperature occurs compared to the conventional roof. Summer roof heat flux estimates show the green roof to have …

Measured Crawlspace Conditions In A Hud-Code Home, Florida Solar Energy Center, David Beal

FSEC Energy Research Center®

The Florida Solar Energy Center conducted research utilizing two unconditioned, old, singlewide side-by-side manufactured homes, one with a ground cover and one with exposed dirt under it. Three different skirting options were tested, open or no skirting, perforated skirting, and solid skirting.

Ambient and crawlspace dewpoints were recorded. The data is summarized in the table below. The skirting configurations tested are in Column 1, Column 2 lists the average ambient dewpoint, 3 the ground cover crawlspace, 4 the exposed dirt crawlspace dewpoint.

Successfully sealing HUD code home crawlspaces is the last piece of the puzzle of floor failures plaguing homes …

School Conditions Will Continue To Earn Failing Grades, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

This study addresses indoor air quality and general conditions problems in schools throughout the United States. Tools employed to investigate conditions include a nationwide, web-based survey, characterization of actual operating conditions in schools through field audits and diagnostic tests, and retrofits in problem schools.

Survey results found temperature to be by far the greatest comfort complaint in regular classrooms, with indoor air quality (IAQ) and then humidity being the next greatest areas of complaints. Ventilation problems were found at each of eight audited schools. These problems appear to be occurring due to a combination of factors including lack of maintenance, …

Comparison Matrix Of Florida Residential Building Energy Code And The International Energy Conservation Code (Iecc) 2006, Florida Solar Energy Center, Mangesh Basarkar

FSEC Energy Research Center®

This report presents a comparison of the differences between the Florida and the IECC (2006) residential energy code requirements. In addition to this summary, the documentation is divided into three sets of distinct comparisons: Comparison of Performance-based methods, Comparison of Prescriptive methods and Comparison of key provisions of the texts. In order to provide the best housing stock, with a code that is easy to implement and enforce, the final recommendation of the study was for Florida to maintain its own code, but consider incorporating some of the newer IECC measures.

Impact Of Solar Powered Disaster-Resistant Communities, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Natural and man made disasters can destroy lives, homes, businesses, the economy and the environment. Disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. This paper identifies the imperative for and value of creating disaster-resistant homes and communities. The use of renewables, the application of distributed generation, implementation of energy-efficient building designs and construction of disaster-resistant structures can minimize the destruction of property, cost of recovery and disruption of lives. Through enhanced construction practices and the use of solar …

Potential Of Energy Efficiency And Renewable Energy Savings To Impact Florida's Projected Energy Use In 2014, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

Florida's 2004 electrical energy use was 233 billion kilowatt-hours. Over half (51%) of this energy use went to residential building energy. The state's current 10-year predictions for electrical energy use in 2014 show a requirement for approximately 308 billion kilowatt-hours of electricity, an increase of approximately 75 billion kilowatt-hours. This study presents an example of how Florida can radically alter its 2014 energy use projection by aggressively pursuing residential building energy efficiency improvements and aggressively increasing its use of proven renewable energy resources.

Unbalanced Return Air In Residences: Causes, Consequences, And Solutions, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Field research performed in 70 central Florida homes found that return grills are almost always located in the central zone of the house, and that individual rooms rarely have ducted return air or return transfer pathways. When interior doors were closed, the closed rooms went to +0.0249 inches of water gauge (in w.g.) (+6.2 pascals (Pa)) wrt outdoors (wrt = with respect to), and the central zone went to -0.0116 in w.g. (-2.9 Pa) wrt outdoors. Room pressures as high as +0.150 in w.g. (+37.3 Pa) and central zone pressure as low as -0.059 in w.g. (-14.7 Pa) wrt outdoors …

Unbalanced Return Air In Commercial Buildings, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Research in 88 central Florida commercial buildings during the last decade has found that 26% of the air distribution systems had substantially unbalanced return air. Unbalanced return air occurs when there is a restriction to air flow between the supply discharge and the return air, creating positive and negative pressure fields throughout the building. Severe consequences in commercial buildings can occur as a result of unbalanced air flows. This paper examines unbalanced return air and its consequences in three commercial buildings, and explains why balancing air flow in buildings is a critical part of maintaining a healthy and energy efficient …

Understanding The Dehumidification Performance Of Air-Conditioning Equipment At Part-Load Conditions, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions - especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and …

Abstract/Conclusion: Understanding The Dehumidification Performance Of Air-Conditioning Equipment At Part-Load Conditions, Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

Air conditioner cooling coils typically provide both sensible cooling and moisture removal. Data from a limited number of field studies (Khattar et al. 1985; Henderson and Rengarajan 1996; Henderson 1998) have demonstrated that the moisture removal capacity of a cooling coil degrades at part-load conditions, especially when the supply fan operates continuously while the cooling coil cycles on and off. Degradation occurs because moisture that condenses on the coil surfaces during the cooling cycle evaporates back into air stream when the coil is off. This degradation affects the ability of cooling equipment to maintain proper indoor humidity levels and may …

Annular Beam Shaping And Optical Trepanning, Danyong Zeng

Electronic Theses and Dissertations

Percussion drilling and trepanning are two laser drilling methods. Percussion drilling is accomplished by focusing the laser beam to approximately the required diameter of the hole, exposing the material to one or a series of laser pulses at the same spot to melt and vaporize the material. Drilling by trepanning involves cutting a hole by rotating a laser beam with an optical element or an x–y galvo-scanner. Optical trepanning is a new laser drilling method using an annular beam. The annular beams allow numerous irradiance profiles to supply laser energy to the workpiece and thus provide more flexibility in affecting …

Study Of Discharge Coefficient And Trends In Film Cooling Effectiveness Of Conical Holes With Increasing Diffusion Angles, Humberto Zuniga,

Electronic Theses and Dissertations

Previous studies indicate that increasing the diffusion angle in conical film-cooling holes leads to an improvement in their film cooling effectiveness. Discharge coefficient and film cooling effectiveness measurements are conducted to characterize this behavior. Part of the focus of this investigation is to find out how this trend develops and attempt to ascertain the optimum cone angle, if possible. Six test plates, each with one row of eight conical-shaped cooling holes of equal diffusion angles of 0, 1, 2, 3, 6, or 8 [degrees], with respect to the hole axis are used in this study. The ratios of the hole …

Efficient Large Scale Transient Heat Conduction Analysis Using A Parallelized Boundary Element Method, Kevin Erhart

Electronic Theses and Dissertations

A parallel domain decomposition Laplace transform Boundary Element Method, BEM, algorithm for the solution of large-scale transient heat conduction problems will be developed. This is accomplished by building on previous work by the author and including several new additions (most note-worthy is the extension to 3-D) aimed at extending the scope and improving the efficiency of this technique for large-scale problems. A Laplace transform method is utilized to avoid time marching and a Proper Orthogonal Decomposition, POD, interpolation scheme is used to improve the efficiency of the numerical Laplace inversion process. A detailed analysis of the Stehfest Transform (numerical Laplace …

Automated Adaptive Data Center Generation For Meshless Methods, Eric Mitteff

Electronic Theses and Dissertations

Meshless methods have recently received much attention but are yet to reach their full potential as the required problem setup (i.e. collocation point distribution) is still significant and far from automated. The distribution of points still closely resembles the nodes of finite volume-type meshes and the free parameter, c, of the radial-basis expansion functions (RBF) still must be tailored specifically to a problem. The localized meshless collocation method investigated requires a local influence region, or topology, used as the expansion medium to produce the required field derivatives. Tests have shown a regular cartesian point distribution produces optimal results, however, in …

Design Optimization Of Solid Rocket Motor Grains For Internal Ballistic Performance, Roger Hainline

Electronic Theses and Dissertations

The work presented in this thesis deals with the application of optimization tools to the design of solid rocket motor grains per internal ballistic requirements. Research concentrated on the development of an optimization strategy capable of efficiently and consistently optimizing virtually an unlimited range of radial burning solid rocket motor grain geometries. Optimization tools were applied to the design process of solid rocket motor grains through an optimization framework developed to interface optimization tools with the solid rocket motor design system. This was done within a programming architecture common to the grain design system, AML. This commonality in conjunction with …

Driver-Gas Tailoring For Test-Time Extension Using Unconventional Driver Mixtures, Anthony Amadio

Electronic Theses and Dissertations

To study combustion chemistry at low temperatures in a shock tube, it is of great importance to increase experimental test times, and this can be done by tailoring the interface between the driver and driven gases. Using unconventional driver-gas tailoring with the assistance of tailoring curves, shock-tube test times were increased from 1 to 15 ms for reflected-shock temperatures below 1000 K. Provided in this thesis is the introduction of tailoring curves, produced from a 1-D perfect gas model for a wide range of driver gases and the production and demonstration of successful driver mixtures containing helium combined with either …

Study Of Low Speed Transitional Regime Gas Flows In Microchannels Using Information Preservation (Ip) Method, Umit Kursun

Electronic Theses and Dissertations

Proper design of thermal management solutions for future nano-scale electronics or photonics will require knowledge of flow and transport through micron-scale ducts. As in the macro-scale conventional counterparts, such micron-scale flow systems would require robust simulation tools for early-stage design iterations. It can be envisioned that an ideal Nanoscale thermal management (NSTM) solution will involve two-phase flow, liquid flow and gas flow. This study focuses on numerical simulation gas flow in microchannels as a fundamental thermal management technique in any future NSTM solution. A wellknown particle-based method, Direct Simulation Monte Carlo (DSMC) is selected as the simulation tool. Unlike continuum …

Study Of Heat Transfer Characteristics Of Impinging Air Jet Using Pressure Andn Temperature Sensitive Luminescent Paint, Quan Liu

Electronic Theses and Dissertations

Luminescent coating measurement system is a relatively new technology for quantitative pressure and temperature measurement. Usually referred to as Pressure Sensitive Paint (PSP) and Temperature Sensitive Paint (TSP), luminescent coatings contain sensor molecules, which undergoes a luminescent transition when excited with light of proper wavelength. The reaction is pressure and/or temperature sensitive. The image of TSP or PSP coated model surface can be captured with a scientific grade camera and then processed to obtain full field temperature and pressure distribution with very high fidelity. The preparation time of the technique is short. The measurement system offers an economic alternative to …

Preliminary Study On The Impact Of Impingement On The Effectiveness Of Film Cooling In The Presence Of Gas Path Pressure Gradient, Anil Peravali

Electronic Theses and Dissertations

Impingement is the most commonly used method of cooling in the hot stages of gas turbines. This is often combined with film cooling to further increase the cooling performance. The mainstream flow where in the coolant films discharge often has large stream wise pressure variations. All existing studies on coupled film and impingement cooling concentrated on the effect of the film depletion on the impingement heat transfer. This study investigates the impact of impingement on film cooling, where the jets impinging on a flat plate are depleted through arrays of film cooling holes in the presence of pressure gradient in …

A Fluid Structure Interaction Model Of Intracoronary Atherosclerotic Plaque Rupture, Eric Teuma-Melago

Electronic Theses and Dissertations

Plaque rupture with superimposed thrombosis is the primary cause of acute coronary syndromes of unstable angina, myocardial infarction and sudden death. Although intensive studies in the past decade have shed light on the mechanism that causes unstable atheroma, none has directly addressed the clinical observation that most myocardial infarction (MI) patients have moderate stenoses (less than 50%). Considering the important role the arterial wall compliance and pulsitile blood flow play in atheroma rupture, fluid-structure interaction (FSI) phenomenon has been of interest in recent studies. In this thesis, the impact is investigated numerically of coupled blood flow and structural dynamics on …

Experiments In Pool Boiling Heat Transfer And Nucleationdynamics Of High Pressure Refrigerants, Daniel Joo

Electronic Theses and Dissertations

A high pressure pool boiling experiment of pressurized R134a is designed and built, utilizing thermochromatic liquid crystal techniques. Liquid crystals thermo-chromatography uses encapsulated liquid crystals that are sensitive to temperature. When exposed to hot temperatures the crystal reflect a blue/violet color, and when exposed to cooler temperatures it reflects a red/orange color. The color value or hue is proportional to its temperature. Using this technique this experiment is capable of studying the physics and thermodynamics of refrigerants under nucleate pool boiling. The main objective of this experiment was the design of the experimental setup. Various designs were tested and validated, …

Design And Performance Evaluation Of An Integrated Miniature Single Stage Centrifugal Compressor And Permanent Magnet Synchronous Motor, Dipjyoti Acharya

Electronic Theses and Dissertations

An attempt has been made in this present work to design, fabricate and performance evaluate an integrated single stage centrifugal compressor and permanent magnet synchronous motor which is a key component of the reverse brayton cycle cryocooler. An off the shelf compressor – the driven and electric motor – the driver was not available commercially to suffice the requirements of the reverse brayton cryocooler. The integrated compressor-motor system was designed and tested with air as the working fluid at mass flow rate of 7.3 grams per sec, with a compression ratio of 1.58 and driven by a 2 KW permanent …

Commissioning Of A Dynamic Mechanical Analyzerfor The Characterization Of Low Temperature Nitife Shape Memory Alloys, Maruthi Diwakar Nandiraju

Electronic Theses and Dissertations

NiTiFe shape memory alloys can undergo transformations between cubic, trigonal and monoclinic phases at low temperatures. The low hysteresis associated with the trigonal R-phase transformation make them candidates for actuator applications at low temperatures. However, the literature available on these alloys is limited and there is a need to establish processing structure-property correlations. This study was undertaken with the objective of determining and understanding such correlations in a Ni46.8Ti50Fe3.2 alloy. First, a dynamic mechanical analyzer (DMA) was successfully commissioned to facilitate mechanical testing between -150 and 600ºC. The experiments performed over selected ranges of stress and temperature probed a range …