81-90 of 238 results
-
Understanding the Coupled Dynamics of Particles and Wall Turbulence
PI Ebenezer Gnanamanickam
This work focuses on understanding the coupled interactions between large and heavy solid particles, on a particle bed, and a gaseous (air) carrier phase turbulent boundary layer developing over the bed.
Part I – The incipient mobilization of particles by the carrier phase is currently predicted by various measures of the mean shear of the carrier phase velocity field. However, there is increasing evidence that particle mobilization is an inherently unsteady process better correlated with the unsteady carrier phase eddies. The proposed work seeks to systematically quantify and understand these unsteady aspects of particle mobilization, particularly as a function of the energy and scale size of the carrier phase eddies. The proposed approach is to introduce flow scales of controlled energy and scale size into a turbulent boundary layer developing over a particle bed, while methodically characterizing the subsequent initiation of particle mobilization. The properties of the particles, namely the diameter and density, will be varied. As the carrier phase is fixed (air), the proposed approach will then describe the processes of particle mobilization as a function of not only the carrier phase eddy energy and size but also the particle Reynolds and Stokes numbers.
Part II – Once particles are mobilized, they form a saltating layer adjacent to the particle bed and become two-way coupled with the carrier phase flow. This interaction, thus far has been reported as modifications to the carrier phase turbulence statistics. However, the exact nature of this interaction has yet to be studied in any further detail. Specifically, the scale dependence or the energy transfer mechanism of this coupled interaction has yet to be described. To study this interaction, it is proposed to carry out careful measurements of the carrier phase turbulent boundary layer in the presence of a saltation layer.
In addition, during the course of both parts of the proposed work, detailed, simultaneous measurements of both phases will be carried out, in a time-resolved manner, to describe the scale dependent characteristics of the underlying physics. This will involve establishing an instantaneous shear velocity that initiates particle mobilization as a function of particle properties as well as carrier phase eddy scale and energy. While studying the interactions during mobilization and after a saltating layer is formed, the goal will be to establish scale dependent energy transfer pathways between the carrier and particle phases. To this end, the primary measurement technique used to characterize the carrier phase will be particle image velocimetry (PIV), while the particle phase velocity fields will be measured using particle tracking velocimetry (PTV). These PIV/PTV measurements will use multiple cameras at multi-scale, providing a detailed description of both phases of the flow at high spatial and temporal resolution. Together these techniques will then provide unique multi-scale, multi-phase measurement sets that will capture the detailed interactions of the particle and carrier phase, leading to new insights into the physics of these interactions.
Categories: Faculty-Staff
-
Understanding the Coupled Interactions Between Hair-Like Micromechanoreceptors and Wall Turbulence
PI Ebenezer Gnanamanickam
This research focuses on understanding the interactions between turbulent flows and long (high aspect ratio), flexible hair-like microstructures or micropillars inspired by those encountered in nature. Some examples include lateral line sensors in fish, airflow sensors in bats and hair cover of animals such as seals and bats.
This research focuses on understanding the interactions between turbulent flows and long (high aspect ratio), flexible hair-like microstructures or micropillars inspired by those encountered in nature. Some examples include lateral line sensors in fish, airflow sensors in bats and hair cover of animals such as seals and bats. These structures perform several physiological functions such as balance and equilibrium sensors, flow sensors, flight control sensors, thermal regulators and water harvesters. Particularly, hair-cell sensors have such structures which in conjunction with the animal's nervous system forms a mechanoreceptive device i.e., they turn a force or displacement, in response to the flow energy, into a nervous system response. These structures that vibrate in response to the background flow are also important in energy harvesting systems. However, these interactions are poorly understood primarily due to the complexity of the underlying physics. Capturing this physics requires simultaneous, combined measurements of the micropillar motion and the flow velocities which are challenging. The proposed research will use advanced image-based flow diagnostic tools to measure in detail the interactions between arrays of these micropillars and the background flow. The planned outreach activities will target a group that is almost exclusively comprised of students who are under-represented in the sciences, while also being economically disadvantaged. The graduate student supported will be involved in outreach activities, inculcating a spirit of outreach into the next generation of engineers.
The interactions between wall turbulence and these micropillars occur in the following manner. Flow structures of scales spanning several orders of magnitude, present within wall turbulence, excites the response of the micropillars. The deflection or vibratory response of the micropillars will then feedback and modify the non-linear, background turbulence, resulting in a non-linearly coupled system. In addition, this interaction occurring at the wall can affect the entire layer resulting in a multiscale interacting layer. Of particular interest are energy transfer pathways between the micropillars and the background turbulence. To describe this coupled interaction and the associated energy transfer mechanisms, advanced diagnostic tools such as multi-camera, multi-resolution, mosaicing particle image velocimetry will be used to capture the dynamics of the background flow while simultaneously tracking the motion of relevant micropillars using particle tracking techniques. Together these tools will provide unique multiscale measurements that will elucidate the coupled physics, advancing fields ranging from physiology to aerospace engineering to non-linear energy systems.
Categories: Faculty-Staff
-
Aeroelastic Gust-Airfoil Interaction Numerical Studies
PI Vladimir Golubev
The project conducted in collaboration with WPAFB and Eglin AFB AFRL scientists over the past 8 years employs DOD HPC and ERAU computer facilities to conduct high-fidelity, low-Reynolds, aeroelastic gust-airfoil interaction studies to model unsteady responses and their control for small UAVs operating, e.g., in highly unsteady urban canyons.
The focus is on modeling airfoil interactions with canonical upstream flow configurations including time-harmonic and sharp-edge gusts, vortices and synthetic turbulence with prescribed characteristics tailored to a specified unsteady flight-path environment. Note that this and other listed projects that include noise predictions and noise/flow control components are partially supported by Florida Center for Advanced Aero Propulsion (FCAAP) in these effortsCategories: Faculty-Staff
-
Self-Sustained Flow-Acoustic Interactions in Airfoil Transitional Boundary Layers
PI Vladimir Golubev
CO-I Reda Mankbadi
This work carries out collaborative theoretical, experimental and numerical investigations of flow-acoustic resonant interactions in transitional airfoils which are responsible for sudden appearance of prominent acoustic tones and unsteady aerodynamic fluctuations in low-Reynolds-number airfoils.
The experimental part of the efforts is implemented in France at anechoic wind tunnel facility of Ecole Centrale de Lyon, while numerical and theoretical studies are conducted at Embry-Riddle using DOD HPC facilities. The project involves several PhD and MSAE students both in U.S. and France.Categories: Faculty-Staff
-
Synthetic Jet-Based Robust MAV Flight Controller
PI Vladimir Golubev
This project conducts theoretical and high-fidelity numerical analyses of UAV robust flight controller employing synthetic-jet actuators (SJAs). The technology-demonstration feasibility study focuses on SJA-based suppression of gust-induced airfoil flutter.
It joins AE and Engineering Physics faculty and students (including undergraduate) in preparation for Phase 2 effort that will include experimental validation and further development and commercialization of the novel flight control technology
Categories: Faculty-Staff
-
Wake Vortex Safety Analysis in the Context of UAS Integration in the NAS
PI Vladimir Golubev
This project is a collaboration with several research organizations under the supervision of FAA. The focus of the current research efforts is on developing and employing variable-fidelity prediction approaches to examine safety implications of the future integration of variable-size UAS systems in the National Aerospace System (UAS).
In particular, variable-fidelity prediction methods to accurately resolve all aspects of aircraft wake generation, evolution, interaction and control are developed. The results of this research will be incorporated in the FAA Integrated Safety Assessment Model developed for analysis of risk implications of UAS operations in the terminal zones and beyond.
Categories: Faculty-Staff
-
Comparison of Grades Based on Learning Mode: How Learning Environment Impacts Grades
PI John Griffith
CO-I Donna Roberts
CO-I Beverly Wood
A comparison of failure rates and grade distribution will be conducted between four learning disciplines utilized by Embry-Riddle Aeronautical University-Worldwide: Eagle Vision Classroom (synchronous classroom to classroom), Eagle Vision Home (synchronous home to home), Online and traditional classroom learning environments. Researchers will examine approximately 20,000 Embry-Riddle end-of-course student grades from the 2015-2016 academic year. The study will determine if significant relationships between failing grades and learning environment (modes) exist between the English, Humanities, Economics and Mathematics disciplines. Due to the continued technological advancements in course delivery, recommendations from previous studies in this area include continued research on the relationship of student performance and learning mode.
Universities are offering a greater number of courses over the Internet in a synchronous mode of instruction, utilizing headsets and webcams along with traditional classroom and online instruction (Foreman & Jenkins, 2005). In light of this continuing shift, this student replicates Dunn's (2013) earlier work, at least in concept, by examining the relationship between learning mode and student performance through analysis of approximately 20,000 student grades.
Embry-Riddle student course grades will be mined from the Campus Solutions database through the ERNIE Dashboard Portal. Data in the form of end of course grades (n=approximately 20,000) for the academic year 2015-2016 will be examined to test the hypotheses. No individual student identification will be obtained, used or reported in this study. Atypical grades including withdraws, incompletes or individual tutorials, will be excluded from the analysis. The researchers plan to use Chi Square tests at the appropriate degrees of freedom (α=.05) to evaluate the data (Gay, Mills, & Airasian, 2006). Four tests will be run for each course discipline (Economics, English, Humanities and Mathematics). The first two tests will evaluate the hypothesis regarding equivalency of failures for all modes of instruction. The first statistical test will compare the number of students who passed versus the number who failed for all modes (EV Home, EV Classroom, On-line and Classroom) of learning. A second statistical test will be conducted comparing just two modes at a time using a 2X2 contingency table to determine if modes and grades are related. Additional tests will be run to evaluate the hypothesis regarding equivalent grade distribution across the learning modes for each discipline. The third test will compare all the modes for each discipline to determine if learning mode and grades are related. The fourth test will allow researchers to compare two modes at a time using a 2X2 contingency table to determine if modes and grades are related.
References
Dunn, L. (2013). A study to compare and contrast student grades and satisfaction levels of traditional classroom and distance learning environments at Embry-Riddle Aeronautical University Worldwide Campus. (Unpublished master's degree Graduate Capstone Project). Embry-Riddle Aeronautical University, Worldwide Campus, Daytona Beach, FL.
Foreman, J., & Jenkins, R. (20015). Full-featured web conferencing systems. Innovate 1 (4) Retrieved from https://courseware.e-education.psu.edu/resources/Article_FullFeaturedWebConferencingSystems.pdf
Gay, L. R., Mills, G. E., & Airasian, P. W. (2006). Educational Research: Competencies for analysis and applications. (8th ed.). Upper Saddle River, New Jersey: Pearson Education, Inc.
Griffith, J. C., Roberts, D. L., & Schultz, M. C. (2014). Relationship between grades and modes of learning. The Journal of American Business Review, Cambridge, 3(1), 81-88.
Categories: Faculty-Staff
-
A Tale of Two Airlines: A Comparative Case Study of High-Road versus Low-Road Strategies in Customer Service and Reputation Management
PI John Griffith
CO-I Donna Roberts
This proposal represents an in-depth comparative case study highlighting the differences in marketing strategies, employee relations and customer (internal and external) service models between American low cost carrier Southwest Airlines and European low cost carrier Ryanair. Analysis will focus on the differing brand personalities of the two airlines, particularly with regard to customer service and its relationship to customer satisfaction and overall corporate success from the early days of these organizations through 2013.
Using a qualitative toll, the differing business strategies will be examined with regard to their adherence or non-adherence to basic business principles as well as theories of psychology and consumer behavior. The researchers will attempt to identify underlying variables and principles that influence the diverging outcomes for these two airlines, paying particular attention to areas that are counter-intuitive and/or challenge some of the widely accepted business practices and ideologies.
The insights gained from this analysis will provide a greater understanding of both the psychology of the air travel consumer and the relative effectiveness of differing marketing models and promotional practices. Based on its exploratory and analytic nature, this study may have possible implications for stakeholders at both the micro and macro levels, including the customers (both internal and external), the specific airlines studied as well as the wider airline industry, and other industries concerned with similar aspects of consumer behavior.
References:
Anderson, R.E. (1973). Consumer dissatisfaction: The effect of disconfirmed expectancy on product performance, Journal of Marketing Research, 10, pp. 38-44
Druckman, D. (2005). Doing research. Thousand Oaks, CA: Sage Publications.
Eckstein, H. (1975). Case studies and theory in Fred Greenstein and Nelson Polsby, eds., Handbook of political science, Vol. 7, pp.79-138. Reading, MA: Addison-Wesley
Helson, H. (1964). Adaptation-level theory. New York, NY: Harper & Row.
Lijphart, A. (1971). Comparative politics and the comparative method. American Political Science Review, 65, (3), pp. 682-693.
Reimer A. & Kuehn R. (2005). The impact of servicescape on quality perception. European Journal of Marketing, 39 (7/8), pp. 785-808. doi: 10.1108/03090560510601761.
Yin, R. K. (2014). Case study research: Design and methods, 5th ed. Los Angeles, CA: Sage Publications.
Yuksel, A., & Yuksel, F. (2001). The expectancy-disconfirmation paradigm: A critique. Journal of Hospitality & Tourism Resarch, 25 (2), pp. 107-131. doi: 10.1177/109634800102500201
Categories: Faculty-Staff
-
2NextGen Task Q: Implementation of NextGen Air Traffic Management system. Airborne Execution of Flow Strategies (AEFS). Modeling, Simulation and Data Analysis
PI Vitaly Guzhva
We work with Metron Aviation, Lockheed Martin, Mosaic ATM and CSSI in development of AEFS concept, designing Modeling and Simulation, collecting data and conducting sensitivity and statistical analyses for concept evaluation.
Airborne Execution of Flow Strategies (AEFS) promotes increased collaboration among National Airspace System (NAS) stakeholders. AEFS recognizes the following current problem: Air Traffic Controllers are aware of the overall air traffic and flight conditions, but lack the capability to collaboratively communicate handling preferences based on flight operators’ business needs, whereas flight operators have limited awareness of Air Traffic Control (ATC) constraints and their potential impacts on flights. By promoting methods to increase collaboration between flight operators and ATC, AEFS targets improvements in Traffic Flow Management (TFM) efficiency, situational awareness among stakeholders, and flexibility in the usage of the NAS.
The FAA conducted research and development of the AEFS concept at the Florida NextGen Test Bed (FTB) at Embry Riddle Aeronautical University (ERAU) in Daytona FL. The research team from ERAU, Metron Aviation, Lockheed Martin, Mosaic ATM, and CSSI demonstrated the AEFS operational scenarios and corresponding use cases through laboratory demonstration as well as Modeling and Simulation (M&S).
The research team conducted two M&S demonstrations: one with Future Concept Team (FCT) members as active participants in the demonstration, and second with FAA stakeholders. Airborne/Airborne; Airborne/Pre-departure; Pre-departure/Airborne; and Pre-departure/pre-departure use cases were recorded and demonstrated to the participants including one airborne/airborne use case with Trial Planning functionality. In all of the use cases, DAL flights originally had default priority 5 that was changed to the highest priority 1 for one of the flights about 10 minutes before that flight would cross the freeze horizon. Based on stakeholder feedback received during the first M&S Demonstration, the FAA demonstrated an additional use case for the second demonstration where one of the flights was instead assigned the lowest priority of 10 to observe the results.
All use cases clearly demonstrated that AEFS would act based on assigned priority reducing sequencing delay for the High Priority Flights (HPF) and increasing it for Low Priority Flights LPF(s). In most cases, more than two flights were involved: a delay from an HPF was distributed among several LPFs, or by increasing delay for an LPF, several higher priority flights were able to decrease their delays. Moreover, the demonstration showed that AEFS successfully altered the arrival sequence based on assigned priorities. Both M&S demonstrations received positive feedback from key stakeholders indicating it was helpful in providing a clearer understanding of the concept.
Categories: Faculty-Staff
-
NextGen Task J: Implementation of NextGen Air Traffic Management system. Integrated Airport Initiative. Benefit-Cost Analysis of Aircraft Arrival Management Systems (AAMS)
PI Vitaly Guzhva
CO-I Ahmed Abdelghany
The main task was to evaluate AAMS implemented at CLT (with US Airways) and MSP (with Delta Airlines) and quantify its costs and benefits.
We collected six months of data before AAMS implementation and 6 months of data after the implementation, conducted statistical analysis and delivered the cost benefit analysis to the FAA.Categories: Faculty-Staff
81-90 of 238 results