Master of Science (MS), Ohio University, 2022, Industrial and Systems Engineering (Engineering and Technology)

The key objective in an emergency evacuation scenario is to allow all occupants to evacuate as quickly and effectively as possible. This is especially important in multi-level structures, as relatively few exits exist in relation to the population size. Numerous factors influence the ability of occupants to evacuate, including individual and environmental factors. Utilizing Pathfinder software, the current study analyzed the effect of agent position and the presence of obstacles on the Total Evacuation Time (TET) of agents exiting an academic building. Results were analyzed for statistical significance using R, showing that concentrating agents in classrooms reduces TET, while adding obstacles in the form of desks increases the average travel distance. The presence of obstacles was found to increase travel distance by influencing agent travel routes, though this did not have an impact on TET. Concentrating agents in classrooms led to improved evacuation by increasing efficiency of movement through corridors. Both factors influenced the evacuation by adding a level of control to detrimental effects like congestion in stairwells and highlighted the importance of travel through building corridors. Increasing the agent population size still increased the TET and travel distance more drastically than either or both other factors, signifying the importance of designing evacuation strategies to capable of accommodating numerous population sizes.

Committee: Dale Masel (Advisor); Diana Schwerha (Committee Member); Dusan Sormaz (Committee Member); Ryan Johnson (Committee Member) Subjects: Industrial Engineering

Doctor of Philosophy, Case Western Reserve University, 2020, Civil Engineering

Seismic risk has increased noticeably in the last decades due to rapid growth of earthquake-prone urban regions and deterioration of aging infrastructure. Meanwhile, mounting evidence of changing climate has reinforced experts' efforts to develop new techniques for sustainable design of structures. Recent studies point to the need for an integrated approach to include both sustainability and resilience criteria in design of building environments. This dissertation integrates seismic resilience quantification methods with economic input-output life cycle assessment and whole-building energy simulation methods to present a new comprehensive decision model for design of building environments. A new multi-criteria decision framework is introduced to integrate various resilience and sustainability measures including asset loss, downtime, number of casualties, greenhouse gas emissions produced by construction, maintenance, and seismic repair, and annual energy consumption and cost. The risk in decision analysis in addition to vulnerability and loss analyses are included via a combined model using analytic hierarchy process, multi-attribute utility theory, and Technique for order preference by similarity to ideal solution (TOPSIS) methods. Results show that with a multi-criteria approach, the benefits of sustainable design techniques can outweigh possible shortcomings in structural performance. The proposed framework is implemented on a series of steel diagrid and reinforced concrete buildings. A comprehensive investigation into the nonlinear dynamic performance of steel diagrids is also conducted and new seismic performance criteria are developed for loss estimation. Diagrids are found to have a substantial collapse capacity but, the non-structural loss due to large maximum absolute floor acceleration may increase expected total loss. Lastly, a new framework is introduced for resilience quantification and rapid safety evaluation of building structures using data obtain (open full item for complete abstract)

Committee: Yu Li PhD (Advisor); Xiong (Bill) Yu PhD, PE (Committee Member); Wojbor Woyczynski PhD (Committee Member); Michael Pollino PhD, PE, SE (Committee Member) Subjects: Civil Engineering; Design; Engineering; Sustainability

Doctor of Philosophy, The Ohio State University, 2019, Food, Agricultural and Biological Engineering

Thermal comfort is an important factor in designing high-quality buildings. The well-conditioned environment can keep occupants healthy and productive and ensure workplace safety. The heating, ventilation and air conditioning (HVAC) system plays an important role in providing and maintaining indoor thermal comfort for buildings. The faults in an HVAC system not only waste energy but also cause poor thermal comfort, building-related illnesses, or even safety accidents. This research adopted the model-based method to detect and diagnose the faults in a selected HVAC system. First, a simulation model of the case study building was created and validated based on both energy and thermal performance. Then, by comparing the indoor air temperatures between the simulation model and the real situation, three common types of faults in the HVAC system were detected for summer and winter, including: 1) control fault, 2) facility fault, and 3) design fault. In addition, the simulation fault was identified in the winter time. For each type of faults, the corresponding solutions were proposed, which will help building operators to locate and solve the faults quickly and accurately. As another important factor to designing high-quality buildings, building energy efficiency could reduce building's energy consumption and their environmental footprint. To lower buildings' significant energy consumption and high impacts on environmental sustainability, recent years have witnessed rapidly growing interests in efficient HVAC precooling control and optimization. However, due to the complex analytical modeling of building thermal transfer, rigorous mathematical optimization for HVAC precooling is highly challenging. As a result, progress on HVAC precooling optimization remains limited in the literature. One of the main contributions of this research is to overcome the aforementioned challenge and propose an accurate and tractable HVAC precooling optimization framework. The main results are (open full item for complete abstract)

Committee: Qian Chen (Advisor); Jia Liu (Committee Member); Sandra Metzler (Committee Member); Lingying Zhao (Committee Member) Subjects: Agricultural Engineering; Civil Engineering; Environmental Engineering; Sustainability

Doctor of Philosophy, The Ohio State University, 2017, Civil Engineering

Progressive collapse is partial or complete collapse of a building, which is triggered by the sudden loss of load-bearing structural elements such as columns and walls. Many computational research studies have been conducted to investigate the progressive collapse mechanism and validation of current design guidelines. However, very few full-scale experiments have been conducted to produce experimental evidence and to evaluate and validate theoretical models. In this dissertation, the progressive collapse performance of masonry wall structures and a steel structure with infill walls have been investigated. Two existing wall structure buildings on the Ohio State University campus (Blackburn House and Nosker House) were tested by physically removing four exterior load-bearing walls consecutively. The mechanical response, including deflection of beams and strain variation in reinforced steel and CMU walls due to the sudden loss of walls, were measured by displacement sensors and strain gauges. Two-dimensional and three-dimensional models were developed using the structural analysis program SAP2000 to simulate the response of test buildings. The calculated response was compared with the experimental data measured in the field. The progressive collapse risk probabilities are evaluated by using current guidelines, and recommendations are made based on the numerical and experimental data generated in this research. New demand capacity ratio acceptance criteria are proposed for progressive collapse evaluation of masonry wall structures. A load increase factor is proposed to perform alternate load path analysis of masonry wall structures. The steel frame building with unreinforced masonry infill walls, Haskett Hall, was previously tested by removing a first story column. Progressive collapse performance of the structure and the contribution of infill walls are examined by modeling the masonry infill walls in the structural analysis program. Based on the numerical simulatio (open full item for complete abstract)

Committee: Halil Sezen (Advisor); Alper Yilmaz (Committee Member); Trunjit Butalia (Committee Member); Chen Qian (Committee Member) Subjects: Civil Engineering

Master of Science (M.S.), University of Dayton, 2017, Renewable and Clean Energy

Photovoltaic-thermal (PVT) technology is a relatively new technology that comprises a photovoltaic (PV) panel coupled with a thermal collector to convert solar radiation into electricity and thermal energy simultaneously. Since cell temperature affects the electrical performance of PV panels, coupling a thermal collector with a PV panel contributes to extracting the heat from the latter to improve its performance. In order to ensure a sufficient temperature difference between the PV cells and the working fluid temperature entering the thermal collector, the circulated water has to reject the heat that has been removed from the PV cells into a relatively colder environment. Borehole thermal energy storage (BTES), which is located underground, often serves as this relatively colder environment due to the stability of underground temperatures, which are usually lower than the working cell temperature. Use of BTES is especially beneficial in summer, when the degradation in cells efficiency is highest. In this thesis, the electrical, thermal, and economic performances of a PVT system are evaluated for three types of buildings -- residential, small office, and secondary school -- in two different climates in the United States, one of which is hot and the other is cold. For each case, two different scenarios are considered. In the first, a PVT system is coupled with BTES, and a ground-coupled heat pump (GCHP) is in use. In the second, a PVT system is coupled with BTES and no GCHP is in use. Each scenarios' GCHP performance is assessed as well. Both the PVT collectors and GCHP performances are evaluated over short and long-term to study the effect of continued ground heat imbalance on both technologies.

Committee: Andrew Chiasson Ph.D. (Committee Chair); Youssef Raffoul Ph.D. (Committee Member); Robert Gilbert Ph.D. (Committee Member) Subjects: Energy; Engineering; Mechanical Engineering

Doctor of Philosophy (Ph.D.), University of Dayton, 2015, Engineering

Currently, there is no integrated dynamic simulation program for an energy efficient greenhouse coupled with an aquaponic system. This research is intended to promote the thermal management of greenhouses in order to provide sustainable food production with the lowest possible energy use and material waste. A brief introduction of greenhouses, passive houses, energy efficiency, renewable energy systems, and their applications are included for ready reference. An experimental working scaled-down energy-efficient greenhouse was built to verify and calibrate the results of a dynamic simulation model made using TRNSYS software. However, TRNSYS requires the aid of Google SketchUp to develop 3D building geometry. The simulation model was built following the passive house standard as closely as possible. The new simulation model was then utilized to design an actual greenhouse with Aquaponics. It was demonstrated that the passive house standard can be applied to improve upon conventional greenhouse performance, and that it is adaptable to different climates. The energy-efficient greenhouse provides the required thermal environment for fish and plant growth, while eliminating the need for conventional cooling and heating systems.

Committee: John Kissock (Advisor) Subjects: Agricultural Engineering; Agriculture; Alternative Energy; Energy; Engineering; Environmental Science; Mechanical Engineering

Master of Science, The Ohio State University, 2012, Mechanical Engineering

This thesis explores the efficiency and performance of residential HVAC systems applied to new high performance buildings which meet the standards of the Passivhaus movement. Chapter 1 recounts the need for energy efficiency as well as the requirements for a Passivhaus. Furthermore, it reviews available building simulation techniques as well as state of the art desiccant dehumidification systems. Chapter 2 details the dynamic simulation in the climate of Columbus, Ohio of The Ohio State University's entry into the 2011 Solar Decathlon competition. This portion of the study explores the use of a conventional vapor compression conditioning system as well as the effects of occupant behavior on the parameters affecting comfort within the structure. It adds to the current literature on the subject by presenting a simulation in a mixed climate where cooling and dehumidification are traditionally required. Furthermore it adopts a simulation tool which acts on time scales less than one hour. It is concluded that the house, while energy efficient, has difficultly controlling moisture levels. In the summer season it is too humid and in the winter it is too dry. Chapter 3 seeks to address these issues through the use and modeling of a new desiccant assisted heat pump designed at Ohio State. Chapter 3 concludes that the new system called HAWC (Hybrid Air/Water Conditioner) is capable of completely eliminating high humidity events in the summer time while still saving energy as compared to a traditional HVAC system. Chapter 4 summarizes the document and lists future work.  

Committee: Mark Walter Dr. (Committee Chair); Gary Kinzel Dr. (Committee Member) Subjects: Mechanical Engineering