Mechanical Engineering Commons^™

Performance Of Four Near Zero Energy Homes: Lessons Learned, Florida Solar Energy Center, Carlos Colon

FSEC Energy Research Center®

While the idea of a zero or near zero energy home is well understood, the actual performance of the structure can be different than expected. High performance homes necessitate increasingly complex envelope, HVAC, water heating, and appliance systems, and successful designs rely on proper function and feedback from those systems to achieve low-energy goals. This paper presents measured data on four near zero energy homes located in Florida that are a part of the U.S. DOE Building America program. The monitored data are compared to both a benchmark model and the prototype computer simulations. By examining the submetered energy data, …

Florida Weatherization Training - Quarterly Report (October 2010-December 2010), Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The weatherization training for the State of Florida Dept of Community Affairs continues at the Florida Solar Energy Center's Training Facility. Progress for the sixth three months of the contract included a five day classroom training on October 18-22 (17 students) and in-field evaluations (16 students).

Building America Industrialized Housing Partnership Case Studies - 2010, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

This document is a compilation of 14 separate case studies of home builders who have adopted Building America principles of high performance as standard construction. This work was compiled by the Building America Industrialized Housing Partnership (www.baihp.org ) for the U.S. Department of Energy to serve as a model for other housing providers. BAIHP is led by the Florida Solar Energy Center of the University of Central Florida.

Florida Weatherization Training - Quarterly Report (July 2010 - September 2010), Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The weatherization training for the State of Florida Dept of Community Affairs continues at the Florida Solar Energy Center's Training Facility. Progress for the fifth three months of the contract included minor course refinement of presentation materials and handouts as the result of the June 2010 updates to the P & G . Four 1-day IR classes were completed (45 students).

Opportunities For Energy Conservation And Improved Comfort From Wind Washing Retrofits In Two-Story Homes - Part I, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Wind washing is a general term referring to diminished thermal control caused by air movement over or through a thermal barrier. The primary focus of this paper is towards a specific type of wind washing where wind can push attic air into the floor cavity between first and second stories of the home through ineffective (or missing) air barriers separating attic space from the floor cavity. A second type of wind washing studied in this project involved insulation batts on knee walls where space between the batts and the wall board allowed air movement against the gypsum wall board. During …

Opportunities For Energy Conservation And Improved Comfort From Wind Washing Retrofits In Two-Story Homes - Part Ii, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Wind washing is a general term referring to diminished thermal control caused by air movement partially or completely bypassing the thermal barrier. The primary focus of this paper relates to a specific type of wind washing where wind can push attic air into the floor cavity between first and second stories of the home through ineffective (or missing) air barriers separating attic space from the floor cavity. A second type of wind washing studied in this project involves insulation batts on knee walls where space between the batts and the wall board allow air movement against the gypsum wall board. …

Affiliate Steps Toward Building Energy Star Homes, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

To certify a home as an Energy Star, a builder works with a RESNET certified home energy rater to evaluate the home with respect to criteria required by the Energy Star program. The following steps will help Habitat affiliates navigate the path toward building Energy Star homes.

Pilot Evaluation Of Energy Savings And Persistence From Residential Energy Demand Feedback Devices In A Hot Climate, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

According to past studies, providing instantaneous feedback on household electrical demand has shown the promise to typically reduce energy consumption by 5-10%. This paper briefly reviews past research and describes a two year pilot evaluation of a low cost residential energy feedback system installed in twenty case study homes in Florida. Although not a statistical sample (the participants were self-selected and interested in reducing energy use), the study showed an average 7% reduction in energy use from feedback homes in the second year of monitoring after controlling for weather-related influences. However, a follow-up evaluation done three years later found little …

Exploring Cost-Effective, High Performance Residential Retrofits Foraffordable Housing In The Hot Humid Climate, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

In 2009, a Department of Energy Building America team led by the Florida Solar Energy Center began working with partners to find cost-effective paths for improving the energy performance of existing homes in the hot humid climate. A test-in energy audit and energy use modeling of the partner's proposed renovation package was performed for 41 affordable and middle income foreclosed homes in Florida and Alabama. HERS1 Indices ranged from 92 to 184 with modeled energy savings ranging from 3% to 50% (average of 26%). Analyses and recommendations were discussed with partners to encourage more efficient retrofits, highlight health and safety …

Evaluation Of Bias Issues Within Regression-Based Inverse Modeling Methods Against Climate And Building Characteristics Using Synthetic Data, Florida Solar Energy Center, Jamie Cummings

FSEC Energy Research Center®

Typically, a model of the energy use of a building is created using the building's characteristics and climate information for its location. However, models of existing homes can be created using monitored energy and climactic data in a process called inverse modeling. Such a technique has potential for those seeking to evaluate the savings a home before and after a retrofit (Meier, Busch, & Conner, 1988).Several programs use an inverse modeling technique to model a home's energy use based on total home energy use, heating and cooling energy use, and indoor/outdoor temperature data from a home (Kissock, Haberl, & Claridge, …

Side-By-Side Testing Of Water Heating Systems Results From 2009-2010 Testing, Florida Solar Energy Center, Carlos Colon

FSEC Energy Research Center®

The Hot Water System (HWS) Laboratory test facility at the Florida Solar Energy Center (FSEC) in Cocoa, FL was used for testing seven differing types of residential water heating systems. The HWS building provides unconditioned housing (similar to a garage in Florida) for one reference electric 50-gallon heater, three solar thermal electric assisted systems, one electric tankless system, one reference 40-gallon natural gas (NG) and tankless gas system. The performance of all seven systems has been compared in a side-by-side test configuration over a full year period. Simultaneous hot water draws take place for all hot water heating systems on …

Field Monitoring And Hourly Simulation Of Energy And Demand Savings From Use Of The Telkonet Ss5000 System Hotel Ac Occupancy Control, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Air conditioning and heating control systems were installed in a 56-room hotel in central Florida. Thermostat setpoints in half of the rooms were adjusted when the room was detected to be unoccupied. Heating and cooling energy use was monitored for a period of 9.5 months. Energy and demand savings were analyzed.

Solar Water Heating Performance: Use Of Energy Factors, Florida Solar Energy Center, Carol Emrich

FSEC Energy Research Center®

The goal of increasing solar energy installations is widely accepted by all. The Florida Solar Energy Center (FSEC) concluded that the goal of increasing solar hot water system installations in Florida could be greatly enhanced by concentrating its efforts on new construction through simplification of the residential building energy code. Since implementation in 1980, the Florida Energy Efficiency Code for Building Construction has required a calculation procedure that assigns multipliers to residential water heating systems. The multiplier for every water heating system type except solar is based on the system's rated efficiency at standard conditions and is a one- or …

Building America Industrialized Housing Partnership (Baihp Ii), Annual Report - Budget Period 4 (Bp4), January 01, 2009 - December 31, 2009, Florida Solar Energy Center, Robert Abernethy

FSEC Energy Research Center®

This annual report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the fourth budget period (BP4) of our contract, January 1, 2009 to December 31, 2009. Progress from the three previous budget periods is included for context.

BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work was performed in four task areas:

• Task 1: System Evaluations
• Task 2: Prototype House Evaluations
• Task 3: Community Scale Evaluations
• Task 4: Post- Phase 3 Activities.

In Task 1, …

[Revised] Updated Miscellaneous Electricity Loads And Appliance Energy Usage Profiles For Use In Home Energy Ratings, The Building America Benchmark And Related Calculations, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

This report addresses the ever increasing percentage of whole house energy use that is attributable to miscellaneous electricity loads (MELs) and major appliances. It builds on earlier U.S. Department of Energy (DOE) reports on the same subject and incorporates the 2005 Residential Energy Consumption Survey (RECS) public use data set to determine how major appliance use is related to the number of bedrooms in existing homes. These data, coupled with existing and proposed DOE appliance testing and labeling standards, are then used to determine a set of baseline lighting and appliance energy end use values for use in the HERS …

Experimental Studies Of The Heat Transfer Characteristics Of Silica Nanoparticle Water-Based Dispersion In Pool Boiling Using Nichrome Flat Ribbons And Wires, Diane Marie Vazquez

Electronic Theses and Dissertations

This work deals with a study of enhanced critical heat flux (CHF) and burnout heat flux (BHF) in pool boiling of water with suspended silica nanoparticles using ribbon-type and wire heaters. Previously our group and other researchers have reported three-digit percentage increase in critical heat flux in silica nanofluids. This study investigates the effect of various heater surface dimensions and cross-sectional shapes on pool boiling heat transfer characteristics of water and water-based nanofluids. CHF and BHF were analyzed for circular and rectangular cross-section nichrome wires and ribbons of increasing sizes in the range of 0.32mm to 2.38mm width, approaching a …

Designing Of Energy Efficient Indoor Environments Using A Localized Radial Basis Function Meshless Method, Victor Huayamave

Electronic Theses and Dissertations

Around the world, the energy over consumption issue has been one of the key socio-economic and political challenges, which has drastically worsened over the last few years. Over the years engineers and environmentalists have proposed several approaches to improve energy efficiency. One is to reduce energy demand by improving consumption habits and a second approach is to introduce the use of a "greener" concept by using biomaterials in a diverse and more efficient manner in engineering construction to create energy efficient environments. This work will investigate the effects of using "green" stabilized earth materials to provide and enhance thermal regulation …

Vaporization Characteristics Of Pure And Blended Biofuel Droplet Injected Into Hot Stream Of Air, Abhishek Saha

Electronic Theses and Dissertations

The combustion dynamics and stability are dependent on the quality of mixing and vaporization of the liquid fuel in the pre-mixer. The vaporization characteristics of different blends of biofuel droplets injected into the air stream in the pre-mixer are modeled in this current study. The focus of this work is on the blended alternate fuels which are lately being considered for commercial use. Two major alternate fuels analyzed are ethanol and Rapeseed Methyl Esters (RME). Ethanol is being used as a substitute for gasoline, while RME is an alternative for diesel. In the current work, the vaporization characteristics of a …

High Heat Flux Spray Cooling With Ammonia On Enhanced Surfaces, Huseyin Bostanci

Electronic Theses and Dissertations

Many critical applications today, in electronics, optics and aerospace fields, among others, demand advanced thermal management solutions for the acquisition of high heat loads they generate in order to operate reliably and efficiently. Current competing technologies for this challenging task include several single and two phase cooling options. When these cooling schemes are compared based on the high heat flux removal (100-1000 W/cm2) and isothermal operation (within several oC across the cooled device) aspects, as well as system mass, volume and power consumption, spray cooling appears to be the best choice. The current study focused on high heat flux spray …

Combustion Dynamics And Fluid Mechanics In Acoustically Perturbed Non-Premixed Swirl-Stabilized Flames., Uyi Idahosa

Electronic Theses and Dissertations

The prevalence of gas turbines operating in primarily lean premixed modes is predicated on the need for lower emissions and increased efficiency. An enhancement in the mixing process through the introduction of swirl in the combustion reactants is also necessary for flame stabilization. The resulting lean swirling flames are often characterized by a susceptibility to feedback between velocity, pressure and heat release perturbations with a potential for unstable self-amplifying dynamics. The existing literature on combustion dynamics is predominantly dedicated to premixed flame configurations motivated by power generation and propulsive gas turbine applications. In the present research effort, an investigation into …

Experimental Analysis On The Effects Of Superficial Liquid And Gas Velocities In The Removal Of Hydrogen Sulfide From A Brine/Oil Mixture, Joshua Lee

Electronic Theses and Dissertations

Hydrogen Sulfide (H2S) is a harmful gas produced during petroleum extraction that leads to corrosion of drilling tools and pipelines. However, a H2S-scavenging liquid compound, when added to pipelines, interacts with liquids that absorbed H2S to create a non-corrosive bi-product. The interaction is associated with the mixing of gases and liquids. This thesis is a study on the effect of superficial gas and liquid velocities on the scavenger's efficiency. This study employs two experimental setups designed to simulate the mixing of gases and liquids within pipelines. A high pressure closed loop was designed and fabricated to determine the influence of …

Parameter Estimation In Heat Transfer And Elasticity Using Trained Pod-Rbf Network Inverse Methods, Craig Rogers

Electronic Theses and Dissertations

In applied mechanics it is always necessary to understand the fundamental properties of a system in order to generate an accurate numerical model or to predict future operating conditions. These fundamental properties include, but are not limited to, the material parameters of a specimen, the boundary conditions inside of a system, or essential dimensional characteristics that define the system or body. However in certain instances there may be little to no knowledge about the systems conditions or properties; as a result the problem cannot be modeled accurately using standard numerical methods. Consequently, it is critical to define an approach that …

Stress Concentration Factors For V-Notched Plates Under Axisymmetric Pressure, Nathan J. Mutter

HIM 1990-2015

The topic of this thesis is the investigation of the local states of stress resulting from the introduction of av-notch in a coaxial circle on the pressurized surface of a circumferentially clamped plate subject to axisymmetric loading. The understanding of the fracture behavior of a component experiencing such a condition is of particular interest to the aerospace and defense industries where circular plate components are often utilized. In such applications, it is imperative that the designer be able to predict the loading conditions facilitating dynamic fracture. As a step towards solving such problems, the quasi-static analogy is studied. Specifically, the …

Experimental And Cfd Investigations Of Lifted Tribrachial Flames, Zhiliang Li

Electronic Theses and Dissertations

Experimental measurements of the lift-off velocity and lift-off height, and numerical simulations were conducted on the liftoff and stabilization phenomena of laminar jet diffusion flames of inert-diluted C3H8 and CH4 fuels. Both non-reacting and reacting jets were investigated, including effects of multi-component diffusivities and heat release (buoyancy and gas expansion). The role of Schmidt number for non-reacting jets was investigated, with no conclusive Schmidt number criterion for liftoff previously known in similarity solutions. The cold-flow simulation for He-diluted CH4 fuel does not predict flame liftoff; however, adding heat release reaction leads to the prediction of liftoff, which is consistent with …

Fundamental Study Of Mechanical And Chemical Degradation Mechanisms Of Pem Fuel Cell Membranes, Wonseok Yoon

Electronic Theses and Dissertations

One of the important factors determining the lifetime of polymer electrolyte membrane fuel cells (PEMFCs) is membrane degradation and failure. The lack of effective mitigation methods is largely due to the currently very limited understanding of the underlying mechanisms for mechanical and chemical degradations of fuel cell membranes. In order to understand degradation of membranes in fuel cells, two different experimental approaches were developed; one is fuel cell testing under open circuit voltage (OCV) with bi-layer configuration of the membrane electrode assemblies (MEAs) and the other is a modified gas phase Fenton's test. Accelerated degradation tests for polymer electrolyte membrane …

Numerical Modeling Of The Shock Tube Flow Fields Before Andduring Ignition Delay Time Experiments At Practical Conditions, Mouna Lamnaouer

Electronic Theses and Dissertations

An axi-symmetric shock-tube model has been developed to simulate the shock-wave propagation and reflection in both non-reactive and reactive flows. Simulations were performed for the full shock-tube geometry of the high-pressure shock tube facility at Texas A&M University. Computations were carried out in the CFD solver FLUENT based on the finite volume approach and the AUSM+ flux differencing scheme. Adaptive mesh refinement (AMR) algorithm was applied to the time-dependent flow fields to accurately capture and resolve the shock and contact discontinuities as well as the very fine scales associated with the viscous and reactive effects. A conjugate heat transfer model …

Experimental Studies Of Liquefaction And Densification Of Liquid Oxygen, Jonathan Koert Partridge

Electronic Theses and Dissertations

Rocketry employs cryogenic refrigeration to increase the density of propellants, such as oxygen, and stores the propellant as a liquid. In addition to propellant liquefaction, cryogenic refrigeration can also conserve propellant and provide propellant subcooling and densification. Previous studies analyzed vapor conditioning of a cryogenic propellant, which occurred by either a heat exchanger positioned in the vapor or by using the vapor as the working fluid in a refrigeration cycle. This study analyzes the refrigeration effects of a heat exchanger located beneath the vapor-liquid interface of liquid oxygen. This study predicts the mass liquefaction rate and heat transfer coefficient for …

A Model Integrated Meshless Solver (Mims) For Fluid Flow And Heat Transfer, Salvadore Gerace

Electronic Theses and Dissertations

Numerical methods for solving partial differential equations are commonplace in the engineering community and their popularity can be attributed to the rapid performance improvement of modern workstations and desktop computers. The ubiquity of computer technology has allowed all areas of engineering to have access to detailed thermal, stress, and fluid flow analysis packages capable of performing complex studies of current and future designs. The rapid pace of computer development, however, has begun to outstrip efforts to reduce analysis overhead. As such, most commercially available software packages are now limited by the human effort required to prepare, develop, and initialize the …

Heat Transfer Augmentation In A Narrow Rectangular Duct With Dimples Applied To A Single Wall, Carson Slabaugh

Electronic Theses and Dissertations

Establishing a clean and renewable energy supply is the preeminent engineering challenge of our time. Turbines, in some form, are responsible for more than 98 percent of all electricity generated in the United State and 100 percent of commercial and military air transport. The operation of these engines is clearly responsible for significant consumption of hydrocarbon fuels and, in turn, emission of green house gases into the atmosphere. With such wide-scale implementation, it is understood that even the smallest increase in the operating efficiency of these machines can lead to enormous improvements over the current energy situation. These effects can …

Processing, Optimization And Characterization Of Fire Retardant Polymer Nanocomposites, Jinfeng Zhuge

Electronic Theses and Dissertations

Fiber reinforced polymeric composites (FRPC) have superior physical and mechanical properties, such as high specific strength, light weight, and good fatigue and corrosion resistance. They have become competitive engineering materials to replace conventional metallic materials in many important sectors of industry such as aircraft, naval constructions, ships, buildings, transportation, electrical and electronics components, and offshore structures. However, since FRPC contain polymer matrix, the polymer composites and their structures are combustible. FRPC will degrade, decompose, and sometimes yield toxic gases at high temperature or subject to fire conditions. The objective of this study is to design and optimize fire retardant nanopaper …