71-75 of 75 results

  • ACTIVE CONTROL OF SUPERSONIC JET NOISE VIA BI-MODAL EXCITATION



    Jet noise is a major problem for both military and commercial aircraft, and there is a lot of interest in ways to reduce it.  In this research project sponsored by the Office of Naval Research, the objective is to implement active control in rectangular jets to reduce the noise.  This is to be done by exciting the jet at a fundamental frequency as well as either a harmonic or subharmonic frequency.  The amplitudes of the excitation are small, thus there should be minimal impact of excitation on aircraft performance.  In doing this, we can manipulate the large-scale structures in the jet, which is the dominant noise source.  The working principle here is that energy from the fundamental mode is transferred to the subharmonic or harmonic, which results in a reduction of the peak noise. 

    In order to compute the noise sources, High-Fidelity Large Eddy Simulations (LES) is done by modifying a code originally developed by the Air Force Research Laboratory, which uses high-order numerical schemes.  However, LES is very computationally expensive and can take weeks to obtain results when running on a supercomputer.  Choosing the wrong excitation parameters can result in zero noise reduction or even enhancement of the noise.  To predict optimal excitation parameters, a Reduced-Order Model (ROM) has been derived to predict the propagation of noise sources in a jet.  Inputs to the ROM can come from linear methods such as Linear Stability Analysis or the Linearized Euler Equations.  Once the ROM is set up, a set of nonlinear differential equations can be solved numerically.  By comparison, this takes only a matter of seconds and does not require the use of a supercomputing cluster.  Using these results, we can observe the damping effect on the dominant noise source, and optimal excitation parameters can be chosen as inputs into LES.

    Current work is focused on performing LES on a Mach 1.5 planar jet, which approximates the flow in the minor plane of a rectangular jet.  This is being done to validate open-loop control using results from the ROM.  Both the symmetric and asymmetric modes will be studied.  Future work will involve performing LES on a Three-dimensional rectangular jet, which will be more representative of a real jet.  Here, closed-loop control can also be implemented.  By measuring the noise signal near the exit of the jet, parameters can be inputted to the ROM to give optimal excitation parameters thereby maximizing the noise reduction.


    Categories: Faculty-Staff

  • Predictive Analytics for Unmanned Aerial Systems Deployment

    ​This research covers unmanned systems deployment in uncertain adversarial environments. Resilient logistics operations call for a holistic and crosscutting approach to proactively address both real-time and persistent adversarial events in several operational areas to outfit mobility platforms, networks, and C2 digital twin to support continued uninterrupted operations.

    This research covers unmanned systems deployment in uncertain adversarial environments. Resilient logistics operations call for a holistic and crosscutting approach to proactively address both real-time and persistent adversarial events in several operational areas to outfit mobility platforms, networks, and C2 digital twin to support continued uninterrupted operations. The research proposes the development of robust mobility platforms for UAV deployment and remote maintenance in adversarial environments with predictive logistics guarantees, including platform reliability evaluation, and remote inspection.

    Categories: Faculty-Staff

  • Pilot Response to Cybersecurity Events

    ​The first research uses the pilot cybersecurity event and risk assessment station located in the Cybersecurity Engineering Lab (LB 131).

    The first research uses the pilot cybersecurity event and risk assessment station located in the Cybersecurity Engineering Lab (LB 131). The station includes a Force Dynamics 401CR flight simulator and a digital twin for scenario development and analysis, and it allows for human systems research on aircraft crew response to external stimuli. The research results are intended to be used to build a training module for aircraft pilots.

    Categories: Faculty-Staff

  • Design Verification of Airborne AI/ML Systems

    ​The verification process of safety-critical systems must ensure system design performs all intended functionality within the required output ranges and safety limits. It must also ensure that no intended functionality is present having a risk larger than the stated development assurance level.

    The verification process of safety-critical systems must ensure system design performs all intended functionality within the required output ranges and safety limits. It must also ensure that no intended functionality is present having a risk larger than the stated development assurance level. The objective of the AI/ML-based system is to assist with the detection of unintended behavior during operations that results in enhanced online hazard analysis and risk mitigation. Validation and verification techniques must be developed for these systems with the future goal of adopting them in airborne operations.

    Categories: Faculty-Staff

  • GAANN

    CO-I William Engblom

    CO-I J. Gordon Leishman

    This project is sponsored by the Department of Education Graduate Assistance in Areas of National Need (GAANN) fellowship program to support six to 10 Ph.D. students of high ability and financial need in the Department of Aerospace Engineering at Embry-Riddle Aeronautical University.

    This project is sponsored by the Department of Education Graduate Assistance in Areas of National Need (GAANN) fellowship program to support six to 10 Ph.D. students of high ability and financial need in the Department of Aerospace Engineering at Embry-Riddle Aeronautical University. The purpose of the program is to enhance and diversify the pool of U.S. citizens who are qualified to teach and pursue research careers in the field of aerospace engineering.

    Embry-Riddle's Aerospace Engineering Department is among the top aerospace engineering programs in the nation. It is currently ranked 32nd for its graduate programs and 8th for its undergraduate program by U.S. News and World Report. The department currently has 34 faculty comprised of distinguished researchers and teachers in the fields of aerodynamics and propulsion, dynamics and control, as well as structures and materials.

    GAANN Fellows will participate in a formal training/teaching program, which will allow them to learn, observe experienced teachers and gain hands-on experience in teaching. Fellows will receive instruction on effective teaching techniques and will be evaluated formally on their teaching. A far-reaching recruitment plan will allow Embry-Riddle to identify outstanding and eligible students, especially from traditionally underrepresented groups. Embry-Riddle is contributing matching funds in the form of tuition and fee assistance. 

    If you are interested in being supported as a GAANN Fellow, please contact Dr. Lyrintzis at lyrintzi@erau.edu.

    Categories: Faculty-Staff

71-75 of 75 results