Mechanical Engineering Commons^™

Improved Duct Systems Task Report With Stagegate 2 Analysis, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The Building America Industrialized Housing Partnership's work with two industry partners, Cavalier Homes and Southern Energy Homes, in constructing and evaluating prototype interior duct systems will be summarized. Issues of energy performance, comfort, DAPIA approval, manufacturability and cost will be addressed. A stage gate 2 analysis will address the current status of project showing that there are still refinements needed to the process of incorporating all of the ducts within the air and thermal boundaries of the envelope.

Orange County Convention Center Energy Analysis And Energy Information System, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

The Orange County Convention Center (OCCC) has the 2nd largest convention facility utilization in the nation. Two primary buildings provide about seven million square feet of conditioned space to approximately 1.5 million visitors per year. In efforts to reduce energy conservation, OCCC began implementing several energy conservation measures beginning in 2005 and continuing over the last 2 years with plans to continue additional efforts in the future. An analysis of monthly chilled water and electricity used by the West and North/South Buildings has been completed in an effort to investigate reductions in energy use resulting from conservation measures. This final …

Commissioning High Performance Residences In Hot, Humid Climates, Florida Solar Energy Center, Ken Fonorow

FSEC Energy Research Center®

Since 2001, the authors have engaged several builders in the Gainesville, FL area to build over 500 high performance new energy efficient homes in multiple sub divisions. The builders keep building to increased levels of energy efficiency. Each home is individually designed, inspected, rated and commissioned for optimum performance. This paper summarizes the experiences to date with two production builders who have cost shared with the Building America program to deliver these outstanding results. Keys to success are commitment from the final decision maker; scopes of work for subcontractors with specific performance criteria; clear communication with the trades often accompanied …

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners. Task 4.2-Develop New Climate-Sensitive Air Conditioner, Design, Construction, And Testing., Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

This study evaluated the performance of a prototype air conditioning system. The configuration of the prototype was based on detailed simulation results performed as part of this study. The results of the previously completed simulation indicated that energy-efficient, properly-ventilated homes in humid climates need equipment options or configurations that can provide a modest amount of additional dehumidification capacity while coordinating their operation with conventional cooling and ventilation systems. A prototype air conditioning system was constructed using currently available components and provides a method to independently control sensible (temperature) and latent (moisture) building loads. The prototype system was tested in both …

Review Of Chilled Water And Electric Energy Use At The West And North/South Buildings Of The Orange County Convention Center, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

The Orange County Convention Center (OCCC) has the 2nd largest convention facility utilization in the nation. Two primary buildings provide about seven million square feet of conditioned space to one million visitors per year. In efforts to reduce energy conservation, OCCC began implementing several energy conservation measures beginning in 2005 and continuing over the last 2 years with plans to continue additional efforts in the future. Examples of the types of energy conservation involved changing lighting and HVAC schedules and control methods, replacement of motors with higher efficiency, and turning off power to other unused equipment. An analysis of monthly …

A Simplified Hot Water Distribution System Model, Florida Solar Energy Center, Lixing Gu

FSEC Energy Research Center®

Water heating in the U.S. has been identified as a major component of total energy consumption used in buildings, mostly coming from the residential sector at around 11%. A potential opportunity for energy savings in water heating systems is to improve the design of hot water distribution systems (HWDS). Due to the complex heat losses of HWDS, models are needed to optimize HWDS by reducing heat losses. There are three models currently used to simulate thermal performance of hot water distribution systems (HWDS): HWSim, ORNL-HWDS, and TRNSYS. The first two models are used to study hot water distribution systems only …

Airflow Network Modeling In Energyplus, Florida Solar Energy Center, Lixing Gu

FSEC Energy Research Center®

The airflow network model in EnergyPlus provides the ability to simulate multizone wind-driven airflows. The model is also able to simulate the impacts of forced air distribution systems, including supply and return air leaks. The air distribution system portion of the model is currently applicable for constant-air-volume systems. Future enhancements will include adding hybrid ventilation control and possible extension to include variable-air-volume distribution systems.

This paper describes the input objects, calculation procedures, model validation, and example results. The model inputs consist of five main objects: simulation control, multizone data, node data, component data, and linkage data. The model calculates pressure …

Solar 2007: Florida's Emergency Shelters Go Solar, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Florida has its fair share of dangerous weather conditions including hurricanes, tornados and floods. Florida legislature passed various laws and made revisions addressing disaster planning which required that the Department of Education, in consultation with school boards and county and state emergency management offices, develop design standards for public shelters to be incorporated into State Requirements for Educational Facilities.

Last year, Solar for Schools, a state program, provided funds to put photovoltaic systems on schools that are classified as shelters, adding a new dimension to the educational program. Middleton High School is an example of an application to power the …

Ucf Recommissioning Project Final Report, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

A research project was carried out to examine the energy savings which occurred from recommissioning three University of Central Florida buildings. Recommissioning activities completed in two of the three buildings yielded chilled water and whole building electricity savings on the order of 15% to 30%. Recommissioning implementation is pending in the third building, where savings are projected to be in the range of 40% to 50% of total building energy use. Additionally, cooling energy savings were monitored (and calculated) for a green roof installation at one of these three buildings. Calculated savings were found to be 1.05 kWh/day for a …

Effectiveness Of Florida's Residential Energy Code: 1979 - 2007, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

No abstract provided.

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners, Task 4 - Develop New Climate-Sensitive Air Conditioner, Simulation Results And Cost Benefit Analysis, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This study evaluated the impacts of conventional and advanced cooling and dehumidification equipment on residential indoor humidity levels and annual energy consumption using whole building computer simulations. The life-cycle cost premium for the various advanced systems was also estimated. Building models were developed for a standard HERS Reference house, meant to represent current residential construction practice, and a High-Efficiency house that would likely qualify for a federal tax credit. The different houses were simulated in seven southeastern U.S. cities and with two ventilation/infiltration scenarios: 1) variable or natural infiltration alone, and 2) mechanical ventilation that complied with ASHRAE Standard 62.2-2004. …

Mitigating The Impacts Of Uncontrolled Air Flow On Indoor Environmental Quality And Energy Demand In Non-Residential Buildings, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This project builds on previous field research in Florida that has demonstrated the significant impact that uncontrolled air flows (UAFs) have on indoor environmental quality (IEQ) and energy use in small commercial buildings, a large but poorly understood segment of the nation's building stock. The goal of this project was to extend that research to a national scale by assessing the importance of UAFs in a sample of 25 commercial buildings in New York State. The differences in climate and construction techniques between New York and Florida are expected to bound the range conditions typically found on a national basis. …

Priorities For Energy Efficiency For Home Construction In Florida, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

Below we provide the priorities for obtaining an energy efficient building in Florida.

Experimental Evaluation Of Nightcool Nocturnal Radiation Cooling Concept: Performance Assessment In Scale Test Buildings, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental test evaluation has been conducted of a night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling- largely during nighttime hours. Available house mass is used to store sensible cooling. Additional dehumidification is done during the evening hours as warranted by interior conditions.

A previous report describes a detailed simulation model of the relevant night cooling …

Heat Transfer In Multi-Layer Energetic Nanofilm On Composites Substrate, Manesh Navid Amini

Electronic Theses and Dissertations

The main purpose of this work is the physical understanding and the numerical description of the reaction of the dense metastable intermolecular composition (MIC). Energy density of MIC is much higher than conventional energetic material; therefore, MIC finds more applications in the propellant and explosive system. The physical model includes the speed of propagation and rate of reaction, and the relationship between the layer thickness, heat rate, and length of the flame based on physical model. In Part I of this thesis, a one-dimensional model based on Weihs was developed for 20 pairs of a multi-layer of aluminum and copper …

High Pressure Testing Of Composite Solid Rocket Propellant Mixtures: Burner Facility Characterization, Rodolphe Valentin Carro

Electronic Theses and Dissertations

Much Research on composite solid propellants has been performed over the past few decades and much progress has been made, yet many of the fundamental processes are still unknown, and the development of new propellants remains highly empirical. Ways to enhance the performance of solid propellants for rocket and other applications continue to be explored experimentally, including the effects of various additives and the impact of fuel and oxidizer particle sizes on burning behavior. One established method to measure the burning rate of composite propellant mixtures in a controlled laboratory setting is to use a constant-volume pressure vessel, or strand …

Solar Energy For Disaster Response Using Space Program Resources, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Satellite pictures, solar radiation levels on the earth's surface, Global Positioning Satellites (GPS) and other space-related resources are available through the efforts of many people and organizations. Satellites' measurements of these resources can be integrated with resources on earth to assess damage from disasters and evaluate resources available to respond. Space-related resources are currently being used by the American Red Cross, the Federal Emergency Management Agency, county Emergency Managers and other organizations. The widest use is in evaluating utility resources and deploying them for repair and emergency power in response to a disaster. Today's use of state-of-the-art satellite and Geographic …

Wall Heat Transfer Effects In The Endwall Region Behind A Reflected Shock Wave At Long Test Times, Corey Frazier

Electronic Theses and Dissertations

Shock-tube experiments are typically performed at high temperatures (≥1200K) due to test-time constraints. These test times are usually ~1 ms in duration and the source of this short, test-time constraint is loss of temperature due to heat transfer. At short test times, there is very little appreciable heat transfer between the hot gas and the cold walls of the shock tube and a high test temperature can be maintained. However, some experiments are using lower temperatures (approx. 800K) to achieve ignition and require much longer test times (up to 15 ms) to fully study the chemical kinetics and combustion chemistry …

Methods Of Extrapolating Low Cycle Fatigue Data To High Stress Amplitudes, David Charles Radonovich

Electronic Theses and Dissertations

Modern gas turbine component design applies much effort into prediction and avoidance of fatigue. Advances in the prediction of low-cycle fatigue (LCF) cracks will reduce repair and replacement costs of turbine components. These cracks have the potential to cause component failure. Regression modeling of low-cycle fatigue (LCF)test data is typically restricted for use over the range of the test data. It is often difficult to characterize the plastic strain curve fit constants when the plastic strain is a small fraction of the total strain acquired. This is often the case with high strength, moderate ductility Ni-base superalloys. The intent of …

Liquid Crystal Thermography Studies In Water Pool Boiling At Subatmospheric Pressures, Kiran Talari

Electronic Theses and Dissertations

A pool boiling experimental facility has been designed and built to investigate nucleate pool boiling in water under sub atmospheric pressure. Liquid crystal thermography, a non intrusive technique, is used for the determination of surface temperature distributions. This technique uses encapsulated liquid crystals that reflect definite colors at specific temperatures and viewing angle. Design of the test section is important in this experimental study. Since a new TLC is required for every new set of test conditions, a permanently sealed test section is not an option. The real challenge is to design a leak proof test section which is flexible …

An Interactive Framework For Meshless Methods Analysis In Computational Mechanics And Thermofluids, Salvadore Anthony Gerace

Electronic Theses and Dissertations

In recent history, the area of physics-based engineering simulation has seen rapid increases in both computer workstation performance as well as common model complexity, both driven largely in part by advances in memory density and availability of clusters and multi-core processors. While the increase in computation time due to model complexity has been largely offset by the increased performance of modern workstations, the increase in model setup time due to model complexity has continued to rise. As such, the major time requirement for solving an engineering model has transitioned from computation time to problem setup time. This is due to …

Lattice Boltzmann Simulation To Study Single And Multi Bubble Dynamics, Amit Gupta

Electronic Theses and Dissertations

In recent years, the lattice Boltzmann method (LBM) has emerged as a powerful tool that has replaced conventional macroscopic techniques like Computational Fluid Dynamics (CFD) in many applications. The LBM starts from meso- and microscopic Boltzmann's kinetic equation to determine macroscopic fluid dynamics. The origins of LBM can be drawn back to lattice gas cellular automata (LGCA); however it lacks Galilean invariance and creates statistical noise in the system. LBM on the other hand does away from these drawbacks of LGCA, and is easy to implement in complex geometries and can be used to study microscopic flow behavior in complex …

A Study Of Syngas Oxidation At High Pressures And Low Temperatures, Danielle Marie Kalitan

Electronic Theses and Dissertations

Ignition and oxidation characteristics of CO/H2, H2/O2 and CO/H2/CH4/CO2/Ar fuel blends in air were studied using both experimental and computer simulation methods. Shock-tube experiments were conducted behind reflected shock waves at intermediate temperatures (825 < T < 1400 K) for a wide range of pressures (1 < P < 45 atm). Results of this study provide the first undiluted fuel-air ignition delay time experiments to cover such a wide range of syngas mixture compositions over the stated temperature range. Emission in the form of chemiluminescence from the hydroxyl radical (OH*) transition near 307 nm and the pressure behind the reflected shock wave were used to monitor reaction progress from which ignition delay times were determined. In addition to the experimental analysis, chemical kinetics calculations were completed to compare several chemical kinetics mechanisms to the new experimental results. Overall, the models were in good agreement with the shock-tube data, especially at higher temperatures and lower pressures, yet there were some differences between the models at higher pressures and the lowest temperatures, in some cases by as much as a factor of five. In order to discern additional information from the chemical kinetics mechanisms regarding their response to a wide range of experimental conditions, ignition delay time and reaction rate sensitivity analyses were completed at higher and lower temperatures and higher and lower pressures. These two sensitivity analyses allow for the identification of the key reactions responsible for ignition. The results of the sensitivity analysis indicate that the ignition-enhancing reaction H + O2 = O + OH and hydrogen oxidation kinetics in general were most important regardless of mixture composition, temperature or pressure. However, lower-temperature, higher-pressure ignition delay time results indicate additional influence from HO2- and CO- containing reactions, particularly the well-known H + O + M = HO2 + M reaction and also the CO + O + M = CO2 + M and CO + HO2 = CO2 + OH reactions. Differences in the rates of the CO-related reactions are shown to be the cause of some of the discrepancies amongst the various models at elevated pressures. However, the deviation between the models and the experimental data at the lowest temperatures could not be entirely explained by discrepancies in the current rates of the reactions contained within the mechanisms. Additional calculations were therefore performed to gain further understanding regarding the opposing ignition behavior for calculated and measured ignition delay time results. Impurities, friction induced ionization, static charge accumulation, boundary layer effects, wall reaction effects, and revised chemical kinetics were all considered to be possible mechanisms for the model and measured data disparity. For the case of wall-reaction effects, additional shock-tube experiments were conducted. For the remaining effects listed above, only detailed calculations were conducted. Results from this preliminary anomaly study are at this time inconclusive, but likely avenues for future study were identified. Additional kinetics calculations showed that the large difference between the experimental data and the chemical kinetics models predictions at low temperatures can be explained by at least one missing reaction relevant to low-temperature and high-pressure experimental conditions involving the formation of H2O2, although further study beyond the scope of this thesis is required to prove this hypothesis both theoretically and experimentally.

The Nature Of Turbulence In A Narrow Apex Angle Isosceles Triangular Duct, Vaidyanathan Krishnan

Electronic Theses and Dissertations

An experimental investigation was performed to ascertain the nature of turbulence in a narrow apex angle isosceles triangular duct. The study involved the design and construction of a low noise, low turbulence wind tunnel that had an isosceles triangular test section with an apex angle of 11.5[degrees]. Experiments involved the measurement of velocity fluctuations using hot wire anemometry and wall pressure fluctuations using a condenser microphone. Measurement of the velocity fluctuations reconfirms the coexistence of laminar and turbulent regions at a given cross section for a range of Reynolds numbers. The laminar region is concentrated closer to the apex while …

Effects Of Position, Orientation, And Infiltrating Material On Three Dimensional Printing Models, Joseph William Frascati

Electronic Theses and Dissertations

This research defined and evaluated mechanical properties of prototypes created using a plaster based three-dimensional printing (3DP) system commercialized by Z Corporation. 3DP is one of the fastest growing forms of rapid prototyping. Till date, there is little or no information available on material properties of infiltrants used in 3DP. This research work evaluated and documented some of the useful information for 3DP users by determining the effect of build position, build orientation and infiltration materials on the strength of prototypes. The study was performed in three different phases to limit the processing variables and to arrive at definite conclusions …