Dr. Cai directs the Smart Buildings Laboratory which houses a fully instrumented psychrometric chamber that can accommodate testing of thermal systems under accurately controlled environmental conditions. The facility is being actively utilized in support of several research projects related to ultra-high efficiency desalination technologies enabled by low-temperature refrigerant cycles, advanced controls of variable-speed heat pump equipment, and grid-interactive efficient buildings. The research efforts are currently supported by DOE, APRA-E, and leading HVAC manufacturers.
Dr. Gorkem Guloglu earned his M.S. and Ph.D. in aerospace engineering from the University of Oklahoma. He has spent most of his time here researching composite materials with Dr. M. Cengiz Altan. Now, Dr. Guloglu teaches students at the very university from which he earned his degrees.
Before coming to OU, Dr. Guloglu knew that he wanted to come to the United States and work with a great professor. He was fascinated with Dr. Altan, who he says is “famous in composite materials.” Once Dr. Guloglu got here, he “really loved OU because the campus is amazing, the people are amazing, and the research facilities have everything.” He said, “we have the freedom to do anything.”
As a master’s and Ph.D. student, Dr. Guloglu worked with two different types of materials which he combined to get the best advantages. In Dr. Altan’s lab he “worked with polymer and ceramic composites to create a different material.” By manufacturing, characterizing, and evolving the materials, he worked to “create a more strong and resilient material without compromising the weight.”
Currently, he lectures on Statics and Space Sciences & Astrodynamics. His favorite thing about OU is the community. He said he has never seen such dedication from students and faculty to a university anywhere else in the world. Although he’s not working in research right now, he continues to write articles about his past work. In the future, he hopes to do research and teach in Turkey as a faculty member at a prestigious university.
Dr. Guloglu’s passion is research because he loves the “independence of [it]. Contributing to science is what excites [him].” He wants to work with different types of polymers and different aspects of improving the polymer system like electrical applications and battery applications. He says, “the current battery technologies aren’t good enough. We need better technologies in battery and composite materials. [He’s] hoping to find a good technology to improve electric cars.”
If a student is curious about research and wants to improve technology and humanity, Dr. Guloglu believes a Ph.D. program is right for them. He said, “It’s a great opportunity. At OU, we have all the technologies, and we have great professors so they can do almost anything. There’s no limit.”
In Spring 2020, AME granted several Undergraduate Research Opportunity Awards (UROA) to faculty and undergraduate students. Dr. Yingtao Liu and his student, Vincent Webster, received one of these awards, which Phillips 66 sponsored. Vincent is a senior in aerospace engineering. About his research, Vincent writes:
My research consisted of developing flexible sensors used in several applications including human motion detection, sensor arrays, soft robotics, biomechanics, structural health monitoring, and prosthetic devices. These sensors measure the force applied to them using a technique called piezoresistivity. Piezoresistivity is characterized as the change in electrical resistance of the material due to an applied deformation. Highly flexible piezoresistive sensors typically decrease their electrical resistance during an applied load. The decrease in resistance occurs due to the variation of microstructures and properties of the materials under loads. To fabricate these sensors, flexible PDMS polymer, was used as the bulk material of the sensor. Carbon nanotubes were uniformly dispersed within the polymer to form the electrical conductive network microstructures. Sugar particles were then added during the fabrication process to create a mixture of carbon nanotube, PDMS, and sugar combination. The sample is then submerged in water to ideally release all the sugar from the sample. The traditional sugar removal method using water can take days to completely remove all the sugar particles. To reduce this extraction time, we would submerge the samples in water and microwave them. This would rapidly increase the temperature of the samples within a minute and the samples would expand and allow water to saturate the sample, leading to the rapid removal of all sugar particles and forming desired open-cell microstructures.
This research built a solid foundation for the rapid manufacturing of piezoresistive polymer foams for broad sensing applications. Our preliminary results have demonstrated that the developed method is able to effectively control materials’ microstructures, enhance carbon nanotube dispersions, and optimize their sensing function. Collaborating with Dr. Liu’s graduate student, Blake Herren, has motivated me to pursue graduate study at OU. Many thanks to the generous support of AME and Phillips 66.
Great job, Vincent!
Dr. Jivtesh Garg and his graduate students are exploring a new class of ultra-hard boron-carbide materials such as BC2N and BC5 for ultra-high thermal conductivity values. Their goal is to achieve thermal conductivity values higher than diamond and graphene (> 5000 W/mK).
They are using quantum-mechanical calculations based on density-functional theory to predict thermal transport properties. Simultaneously the group is using laser-based frequency-domain thermoreflectance measurements (FDTR) to experimentally measure these high thermal conductivity values. Ph.D. students Rajmohan Muthaiah, Avinash Nayal, and Roshan Annam are conducting this research.
The group has also developed advanced functionalization schemes to more efficiently couple graphene with polymers for thermal transport applications. Graphene is a wonder material with extraordinary thermal, mechanical, and electrical properties. By efficiently coupling graphene with polymer, a large enhancement in properties can be achieved. Initial experimental results suggest dramatic improvement in the thermal conductivity of polymers such as polyetherimide. Developed functionalization schemes are being applied to a wide range of polymers. Ph.D. students Fatema Tarannum and Swapneel Danayat are involved in this research.
They are further exploring non-equilibrium phonon effects for the design of high-efficiency hot carrier solar cells and thermoelectric materials. Electrons in solar cells thermalize through interactions with lattice vibrations (phonons). By engineering non-equilibrium phonon effects to generate hot phonons, the thermalization of electrons can be inhibited, thereby enhancing solar cell efficiency. Non-equilibrium phonon effects also enhance the efficiency of thermoelectrics by mitigating heat loss through lattice vibrations. Fundamental first-principles techniques coupled with Monte-Carlo simulations are being used to study non-equilibrium phonon effects.
Through advanced simulations and state-of-the-art experimental measurements, the group aims to develop the next generation of advanced composite materials for thermal management and energy conversion applications and is a world leader in thermal management technologies.
Tess Hartog, Md Tanvir Ahad, and Amin Alhashim are working together to explore the uses of electroencephalogram (EEG) to understand neuro-responses as they pertain to creativity in engineering. They are working under Dr. Zahed Siddique; Tess Hartog is an ME MS student with a background in math and psychology, Tanvir is an ME Ph.D. student with a background in EE, and Amin is an ISE Ph.D. student. Megan Marshall was a former fellow who graduated with her MS in AE in the summer of 2020.
The main objective of the research is to study creativity in engineering by gaining a deep understanding of how creative thoughts form and how the brain responds to different levels of creative products. The students are currently utilizing EEG to capture the neurological behaviors and responses when conducting research.
Amin’s work focuses on three areas: creativity definitions, creativity models, and the effect of cues on creativity. Through text analysis techniques, Amin is analyzing a corpus of creativity definitions extracted from literature to understand how creativity is being perceived by engineers and non-engineers. There are many models for creativity and Amin is working on a classification scheme based on their similarity. Such classification is important for the advancement of creativity research as evident in the history of sciences. Amin’s last area of focus is on the effect of cues on creative behavior and its relationship with how the brain behaves through the use of EEG.
Tess’s work focuses on a subset of EEG recording called event-related potentials (ERPs), which are time-locked neural responses to stimuli. Specifically, she investigates the ERPs (the N400response) of engineers to creative stimuli. Tess is also working on analyzing the EEG recordings of engineers during engineering design-related problems and examining whether exposure to creative stimuli will improve designs. Below are some of her preliminary ERP findings. As indicated in the pictures, she looks for differences in negative wave amplitudes for three types of stimuli around 400 milliseconds post-stimulus presentation (i.e. the N400).
Defining creativity is hard but the measurement of creativity is even harder. To capture the multifaceted nature of creativity; more than a hundred measurement techniques have been developed and applied including neurocognitive approaches. The brain’s neural dynamics related to creativity should be accounted to quantify the relationship between the brain regions. During divergent thinking, EEG studies aid temporal dynamics of the neuronal activations underlying cognitive insight. In order to solve real-world problems, creativity is a must for engineers. Engineers’ involvement with creative tasks; activate brain regions corresponding to the task’s demand. Identifying the significant brain temporal regions engaged with the creative tasks for engineers is a crucial question. Brain-computer interfaces (BCIs) which are based on event-related potentials (ERPs) have the potential ability to estimate a user’s task involvement. Therefore, the question comes: Is the creativity (neural activity) of engineers detected by ERP-Based Brain-Computer Interfaces task-specific? Tanvir’s research work focuses on addressing these questions in the Neurocognitive creativity research domain.
Management of waste water is a challenging issue in many municipal and industrial sectors. The oil and gas industry produces a massive amount of waste water during production. The production of one barrel of oil results in approximately nine barrels of water that is contaminated with salt, heavy metals, and organic compounds. The development of methods for cost-efficient disposal and re-use of produced water without damage to the environment is a critical need for the oil and gas industry. Also, re-use of the water for agricultural purposes will be helpful because the agricultural sector is a primary consumer of increasingly scarce freshwater (accounting for 63% of U.S. surface water withdrawals, according to the U.S. Geological Survey).
In this project sponsored by the US Department of Energy, Drs. Shabgard, Cai and Parthasarathy are working on the development of a novel, zero-liquid discharge freeze system to remove dissolved salt from contaminated water. Freeze-desalination processes are well suited for these situations because pure ice crystals can be produced even in highly concentrated brine. However, current freeze-desalination technologies have some deficiencies that hinder their widespread use. A new method of eutectic freeze desalination will be used with a cooling approach that maximizes efficiency. Thus, the need for energy-intensive evaporation methods is avoided. The density differences between water, ice, and salty brine are used to separate the components. The system will operate under atmospheric pressure and be capable of treating highly concentrated/contaminated water. If successful, the treated water will be suitable for agricultural use, providing an abundant new water source. The goal is to develop a zero-liquid discharge (ZLD) freeze-desalination system capable of treating water with total dissolved solids (TDS) values up to 250,000 mg/l (milligrams per liter). For comparison, the TDS content of seawater is approximately 35,000 mg/l.
The proposed system offers a sustainable solution for the increasing water demand in industrial and oil and gas sectors by recycling the otherwise wasted water, without putting pressure on increasingly scarce fresh water resources also in demand by local communities for agricultural and municipal purposes. Also, the environmental concerns related to disposing of highly contaminated water are avoided by the use of the proposed ZLD desalination system.
Dr. Li Song, an associate professor at AME, received three awards for her current research projects. Two awards are from the Department of Energy, and the third award is from Battelle – Pacific Northwest National Laboratory.
Song is the lead PI for the development and validation of a home comfort system for total performance deficiency/fault detection and optimal control project, which received a DOE fund of $993,149. The research team will develop and validate a smart thermostat-integrated low-cost home energy management system, including a data connection framework; a computationally efficient, self-learning home thermal model; automatic fault detection and analysis algorithms; and home energy management information and controls based on in-situ measured efficiencies of heating and cooling equipment, the air distribution system, and the building envelope.
The second DOE fund is $551,566 for the performance demonstration of an occupancy sensor-enabled integrated solution for commercial buildings project. The research team will validate the performance and savings of three HVAC control (fan, cooling coil valve, outside air) algorithms integrated with occupancy sensing data to optimize ventilation delivery.
A $50,000 award was given to Song from Battelle – Pacific Northwest National Laboratory for her “Transactive-Control Based Connected Home Solution for Existing Residential Units and Communities” project.
This is a summary of Song’s research proposal sent to Battelle: To obtain the overall project aims, the development of machine learning techniques to calibrate the initial physical model that estimates and predicts energy use of a house and its response to control signals is extremely important. An effective home thermal model, that can predict the indoor air temperature dynamics under different weather, HVAC output and internal gains from appliances and occupants, is essential for the development.
BEEL initiated the development of a self-learning home thermal model two years ago. The BEEL home model, currently limited for a house with an A/C and gas-furnace heater, can automatically identify the model parameters with minimum data needed and precisely predict the space temperature and home HVAC energy uses for a house. To enhance the connectivity and compatibility of the platform proposed by PNNL, BEEL is committed to expand the home thermal model for a heat pump system and test enhanced home model using two houses located in Oklahoma through the partnership with OG&E. The challenge of modeling the heat pump is that the heating output from a heat pump is no longer constant as-is for a gas furnace heater. A correlation of the heating output of a heat pump and outdoor air temperature needs to be formulated and similarly, a correlation between cooling output of a heat pump and weather might be needed for cooling season as well.
Congratulations Dr. Song!
Additional News About Dr. Song’s Research:
Dr. Song’s Research is Promoted in the Press
Dr. Song Receives 2018 ASHRAE Technical Paper Award
A newly funded project in the School of Aerospace and Mechanical Engineering makes use of close collaboration between researchers in different fields to improve a critical technology for national defense. Dr. Keith Walters and Dr. Andrea L’Afflitto (now a faculty member at Virginia Tech) are combining their respective expertise in aerodynamics and controls to address a difficult challenge for unmanned aerial vehicles (UAVs).
It is well known that UAVs are increasingly being used for both commercial and military applications. The United States Department of Defense (DoD) currently employs multi-rotor helicopters (quadcopters) for remote sensing missions, such as surveillance and search and rescue. In the future, they will support troops by performing tactical tasks, such as picking up and dropping off payloads and surveying cluttered environments. Of particular interest are vehicles that operate autonomously, that is without any direct control by human pilots. These vehicles use onboard computers and mathematical control algorithms to perform necessary aerial maneuvers, travel to desired locations, avoid obstacles, and perform whatever tasks are required of their mission. The development of new and improved control algorithms is, therefore, an active area of research with the potential for substantial impact on next-generation UAVs.
This project focuses on the development of improved control algorithms specifically designed for the landing of UAVs on U.S. Navy ships. Shipboard landing is a complex task for UAVs because 1) the deck is highly unsteady in rough seas; 2) adverse sea conditions are often accompanied by adverse weather and high winds; 3) the superstructure of a moving ship induces a wake in the air, which further perturbs the UAVs landing on its deck; 4) near hard surfaces, the ‘ground effect’ alters the thrust produced by the propellers; and 5) UAVs returning from a mission may be damaged. To land on the deck of a ship, a UAV’s control system regulates the thrust forces of each propeller so that the aircraft approaches the ship with some desired relative velocity and orientation, leading to (hopefully) a gentle touch down in the appropriate location.
The primary objective of this research is to design a robust adaptive control system for multi-rotor UAVs that allows precise landing on the deck of moving ships. The work builds on prior research by former AME faculty member Andrea L’Afflitto and will make use of a model reference adaptive control (MRAC) architecture. Such an approach guarantees robustness of the closed-loop feedback system to both uncertainties in system parameters and unknown state-dependent disturbances that affect the control inputs, such as wind gusts or the swinging of an attached cargo payload.
The control algorithm will also be improved by adopting more realistic functional relationships between propeller rotational speed (RPM) and the generated thrust. Currently, it is assumed that thrust is simply proportional to RPM squared under all conditions. While this is often nearly true when a UAV is hovering in calm air, it does not hold during complex aerial maneuvers, under the action of strong wind disturbances, or when the vehicle is close to a solid surface such as the deck of a ship. Keith Walters and his students will perform computational fluid dynamics (CFD) simulations of quadrotor propellers to more accurately determine the relationship between thrust and RPM under these conditions. The simulations will be used to develop an analytical function that will be included in the control algorithm developed by Dr. L’Afflitto.
The scientific advances made by this project will be disseminated in the technical literature and will provide opportunities for graduate students to participate in national or international conferences. The improvement to UAV performance during shipboard landing will be critical to increasing the value of these vehicles to U.S. Navy missions, and the technology can be translated to other branches of the armed forces to improve design and operation of their next-generation UAV systems. Eventually, the research may be adopted by the commercial sector to improve, for example, the use of UAVs for package delivery or remote sensing in adverse weather conditions.
The AME Student Research Spotlight this month is Devin Laurence, a member of the Biomechanics and Biomaterials Design Lab (BBDL). Laurence is a graduate student in the BBDL at the University of Oklahoma studying mechanical engineering. His specific research project involves computational modeling of the tricuspid heart valve to move towards patient-specific therapeutics. He plans to pursue his Ph.D. with an emphasis on cardiovascular biomechanics and to continue into academia afterwards. In his free time, Devin enjoys playing chess, disc golf, and hiking/camping.
Click here for more information about the BBDL.
The AME Student Research Spotlight this month is Sam Jett, a member of the Biomechanics and Biomaterials Design Lab (BBDL). Jett is a graduate student at the University of Oklahoma, working on his master’s degrees in mechanical engineering. Sam started out in the BBDL working on the biaxial testing project for heart valve leaflet tissue and is currently working to design a collagen imaging system that will integrate with the biaxial tester to study how dynamic loading affects collagen fiber orientation and alignment in biological tissues. In the lab, he enjoys exploring the biological imaging field, writing code to gain valuable insights from data, collaborating with other lab members, and exercising the freedom to work with teams to develop innovative solutions to research goals. Outside of school, Sam spends time walking his dog, reading, exercising, hanging out with his friends, and enjoying the occasional night out on the town. He hopes to work on biomedical device and software design and after completing his M.S. studies at OU.
Click here for more information about the BBDL.