Dynamical Systems and Control
Quantum and Non-Equilibrium Processes
Information, Decision and Complex Networks
Complex Material and Devices
Energy, Power and Propulsion
Basic Research Initiatives
Dynamical Systems and Control (RTA)
The Dynamical Systems and Control Department leads the discovery and development of the fundamental and integrated science that advances future air and space flight. The broad goal of the division is to discover and exploit the critical fundamental science and knowledge that will shape the future of aerospace sciences. A key emphasis is the establishment of the foundations necessary to advance the integration or convergence of the scientific disciplines critical to maintaining technological superiority. A wide range of fundamental research addressing mathematics, materials, fluid dynamics, and structural mechanics are brought together in an effort to increase performance and achieve unprecedented operational capability. The division carries out its ambitious mission through leadership of an international, highly diverse and multidisciplinary research community to find, support, and fosters new scientific discoveries that will ensure future novel innovations for the future U.S. Air Force.
The central research direction for this Department focuses on meeting the basic research challenges related to future air and space flight by leading the discovery and development of fundamental science and engineering in the following research areas:
Program Description: This program seeks to develop innovative mathematical methods and fast, reliable algorithms aimed at making radical advances in computational science. Research in computational mathematics underpins foundational understanding of complex physical phenomena and leads to capabilities for analysis and prediction of phenomena crucial to design and control of future U.S. Air Force systems and processes. Proposals to this program should focus on fundamental scientific and mathematical innovations. Additionally, it is desirable to frame basic research ideas in the context of applications of relevance to the U.S. Air Force which can serve simultaneously to focus the research and to provide avenues for transition of basic research outcomes into practice. Applications of current interest include, but are not limited to, unsteady aerodynamics, plasma dynamics, propulsion, combustion, directed energy, information science, and material science.
Basic Research Objectives: Research under this program has traditionally emphasized schemes that address the discretization and numerical solution of complex systems of equations, generally partial differential equations that arise from physics. Nevertheless, alternative phenomenological models and computational approaches are of interest, particularly in connection with emerging applications involving information and biological sciences. One area of increasing emphasis is simulation of complex systems with dynamic data integration. Issues such as multiscale and multi-modal description of the system, dynamic invocation of appropriate models based on interjection of data into the simulation systems, stable and convergent algorithms which are robust under perturbations from dynamic-data inputs, and Uncertainty Quantification (UQ) analysis for these systems are of importance.
To meet the formidable computational challenges entailed in simulating nonlinear, discontinuous, multi-physics and multi-scale problems of interest to the U.S. Air Force, the program is examining numerical algorithms that include multi-scale and multi-physics approaches with particular emphasis on convergence, error analysis, and adaptivity. A spectrum of numerical methods in these areas are being developed and improved within the scope of the program, including high-order spatial and temporal algorithms, mesh-free and particle methods, high-order moving interface algorithms, and hybrid methods. The other areas of interest are rigorous model reduction techniques with quantifiable fidelity for efficient and robust multidisciplinary design and optimization, scalable algorithms for multi-core platforms and also uncertainty quantification. The active areas of interest in UQ include development of high accuracy stochastic numerical methods, stochastic model reduction and long term time integration techniques. Given the emerging computing platforms, including multicore-based platforms with complex architectures, the program is considering fundamental research on the mathematical aspects of scalable solvers with emphasis on parallelism across scales, high-order discretization, and multi-level domain decomposition techniques. Research in the Computational Mathematics program also supports the national program in high performance computing.
Dr. Fariba Fahroo AFOSR/RTA (703) 696-8429
DSN 426-8429; FAX (703) 696-7360
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Dynamics and Control
Program Description: This program emphasizes the interplay of dynamical systems and control theories with the aim of developing innovative synergistic strategies for the design and analysis of controlled systems that enable radically enhanced capabilities, including performance and operational efficiency for future U.S. Air Force systems. Proposals should focus on the fundamental science and mathematics, but should include connectivity to appropriate Air Force applications. These applications currently include information systems, as well as autonomous/semi-autonomous aerial vehicles, munitions, and space vehicles.
The dramatic increase in complexity of Air Force systems provides unique challenges for the Dynamics and Control Program. Meeting these challenges may require interdisciplinary approaches as well as deeper studies within single disciplines. Lastly, note that the Dynamics and Control Program places special emphasis on techniques addressing realistic treatment of applications, complexity management, semi-autonomous systems, and real-time operation in stochastic and adversarial environments.
Basic Research Objectives: Current research interests include: adaptive control and decision making for coordinated autonomous/semi-autonomous aerospace vehicles in uncertain, information rich, dynamically changing, networked environments; understanding how to optimally include humans in the design space; novel schemes that enable challenging multi-agent aerospace tracking in complex, cluttered scenarios; robust and adaptive non-equilibrium control of nonlinear processes where the primary objective is enhanced operability rather than just local stability; new methods for understanding and mitigating the effects of uncertainties in dynamical processes; novel hybrid control systems that can intelligently manage actuator, sensor, and processor communications in a complex, spatially distributed and evolving system of systems; sensor rich, data driven adaptive control; novel approaches and methods where dynamic resources in sensor networks and networks of controllers are adaptively managed through a dynamic feed-back loop symbiotically integrating simulations and models with real-time data-acquisition and control systems; managing adversarial and stability issues for systems in cyberspace; and applying control concepts motivated by studies of biological systems. In general, interest in the control of large complex, multi-scale, hybrid, highly uncertain nonlinear systems is increasing. Further, new mathematics in clear support of dynamics and control is of fundamental importance. In this regard, some areas of interest include, but are not limited to, stochastic and adversarial systems, partial and corrupted information, max-plus and idempotent methods, game theory, nonlinear control and estimation, and novel computational techniques specifically aimed at games, control and systems theory.
Dr. Fariba Fahroo AFOSR/RTA (703) 696-8429
DSN 426-8429; FAX (703) 696-7360
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Flow Interactions and Control
Program Description: The Flow Interactions and Control portfolio supports basic research into the motion and control of aerodynamic shear flows, including the interactions of these flows with rigid and flexible surfaces. The portfolio is interested in aerodynamic interactions arising in both internal and external flows and extending over a wide range of Reynolds numbers. The portfolio seeks to advance fundamental understanding of complex, time-dependent flow interactions by integrating theoretical/analytical, numerical, and experimental approaches. The focus on the understanding of the fundamental flow physics is motivated by an interest in developing physically-based predictive models and innovative control concepts for these flows. Research in this portfolio is motivated, in part, by the unique fluid-structure interactions that are found in nature, in vortex and shear layer flows, and on small-scale, unmanned air vehicles.
Basic Research Objectives: The portfolio emphasizes the characterization, modeling/prediction, and control of flow instabilities, turbulent fluid motions, and fluid-structure interactions for both bounded and free-shear flows with application to aero-optics, surfaces in actuated motion, flexible and compliant aerodynamic surfaces, vortical flows, and flows with novel geometric configurations. The portfolio maintains an interest in the dynamic interaction between unsteady fluid motion, nonlinear structural deformations, and aerodynamic control effectors for a wide range of flight regimes. Although the portfolio has a strong emphasis in flow control, studies examining underlying flow physics with a path to enabling control of the flow are also of interest. Studies integrating modeling, control theory, and advanced sensor and/or actuator technology for application to a flow of interest are encouraged. Flow control studies are expected to involve a feedback approach based on a fundamental insight into the flow physics.
Prospective researchers are strongly encouraged to submit short (max 6 pages) White papers to the Program Officer prior to developing full proposals. White papers are viewed as a valuable first step in the proposal development and submission process. White papers should briefly describe the proposed effort, illustrate how it will advance the current state-of-the-art, and address the relevance to U.S. Air Force interests. Note, however, that basic research of the variety typically funded by the portfolio may not yet have a clear transition map to an application. The integration of theoretical, numerical, and experimental tools to improve understanding is encouraged. An approximate yearly cost for a three year effort should also be included. Researchers with White papers of significant interest will be invited to submit full proposals.
Dr. Douglas Smith AFOSR/RTA (703) 696-6219
DSN 426-6219; FAX (703) 588-1003
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Multi-Scale Structural Mechanics and Prognosis
Program Description: This fundamental basic research program addresses the U.S. Air Force needs in the following application areas: 1) New and revolutionary flight structures, 2) Multi-scale modeling and prognosis and 3) Structural dynamics under non-stationary conditions and extreme environments. Other game-changing and revolutionary structural mechanics problems relevant to the U.S. Air Force are also of interest.
The structural mechanics program encourages fundamental basic research that will generate understanding, models, analytical tools, numerical codes, and predictive methodologies validated by carefully conducted experiments. The program seeks to establish the fundamental understanding required to design and manufacture new aerospace materials and structures and to predict their performance and integrity based on mechanics principles.
Basic Research Objectives: Fundamental basic research issues for new and revolutionary flight structures include: revolutionary structural concepts and unprecedented flight configurations; hybrid structures of dissimilar materials (metallic, composite, ceramic, etc. ) with multi-material joints and/or interfaces under dynamic loads, and extreme environments; controlled-flexibility distributed-actuation smart structures. The predictive analysis and durability prognosis of hybrid-material structures that synergistically combine the best attributes of metals, composites, and ceramics, while avoiding their inherit shortcomings are of great interest.
Fundamental basic research issues of interest for multi-scale modeling and prognosis include: physics-based models that quantitatively predict the materials performance and durability of metallic and composite flight structures operating at various regimes; modeling and prediction of the structural flaws distribution and service-induced damage on each aircraft and at fleet level; structural analysis that accounts for variability due to materials, processing, fabrication, maintenance actions, changing mission profiles; novel and revolutionary on-board health monitoring and embedded NDE concepts. An area of particular research interest is the development and validation of new diagnostic techniques capable of measurements at the mesoscale. Experimental techniques capable of simultaneous measurements on multiple length scales (i.e. meso to macro) are also sought.
Fundamental basic research issues for structural dynamics include: control of dynamic response of extremely flexible nonlinear structures; control of unsteady energy flow in nonlinear structures during various flight conditions; nonlinear dynamics and vibration control of thin-wall structures of functionally graded hybrid materials with internal vascular networks under extreme loading conditions.
Researchers are highly encouraged to submit short White papers prior to developing full proposals. White papers are encouraged as an initial and valuable step prior to proposal development and submission. White papers should briefly relate the current state-of-the-art, how the proposed effort would advance it, and the approximate yearly cost for a three to five year effort. Researchers with White papers of significant interest will be invited to submit full proposals.
Dr. David Stargel AFOSR/RTA (703) 696-6961
DSN 426-6961; FAX (703) 696-7320
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Optimization and Discrete Mathematics
Program Description: The program goal is the development of mathematical methods for the optimization of large and complex models that will address future decision problems of interest to the U.S. Air Force. Areas of fundamental interest include resource allocation, planning, logistics, engineering design and scheduling. Increasingly, the decision models will address problems that arise in the design, management and defense of complex networks, in robust decision making, in performance, operational efficiency, and optimal control of dynamical systems, and in artificial intelligence and information technology applications.
Basic Research Objectives: There will be a focus on the development of new nonlinear, integer and combinatorial optimization algorithms, including those with stochastic components. Techniques designed to handle data that are uncertain, evolving, incomplete, conflicting, or overlapping are particularly important.
As basic research aimed at having the broadest possible impact, the development of new computational methods will include an emphasis on theoretical underpinnings, on rigorous convergence analysis, and on establishing provable bounds for (meta-) heuristics and other approximation methods.
Dr. Fariba Fahroo AFOSR/RTA (703) 696-8429
DSN 426-8429; FAX (703) 696-7360
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Sensory Information Systems
Program Description: This program coordinates multi-disciplinary experimental research with mathematical, neuromorphic, and computational modeling to develop the basic scientific foundation to understand and emulate sensory information systems. Emphasis is on (a) acoustic information analysis, especially in relation to human auditory perception, and (b) sensory and sensorimotor systems that enable 3D airborne navigation and control of natural flight, e.g. , in insects or bats, especially in relation to capabilities of autonomous biological systems not yet emulated in engineered flight.
Basic Research Objectives: One program goal is to forge new capabilities in acoustic analysis, especially to enhance the intelligibility and usefulness of acoustic information. The primary approach is to discover, develop, and test principles derived from an advanced understanding of cortical and sub-cortical processes in the auditory brain. Included are efforts to model and control effects of noise interference and reverberation, understand the psychoacoustic basis of informational masking, develop new methods for automatic speech detection, classification, and identification, and enable efficient 3D spatial segregation of multiple overlapping acoustic sources. Signal analysis methods based upon purely statistical or other conventional "blind source" approaches are not as likely to receive support as approaches based upon auditory system concepts that emphasize higher-level neural processes not yet fully exploited in engineered algorithms for acoustic information processing. Examples of such higher-level approaches recently supported are time-domain (modulation) filtering and representation, vocal tract/glottal pulse normalization, and spectro-temporal analysis based upon properties of cortical receptive fields. Although this program's grantees have built a rich tradition of technical innovation in the acoustics area, with many important engineering applications for the Air Force, as well as for other governmental entities and the commercial sector, this program's priority remains the advancement of the basic science that serves as a foundation for technical progress. The program is multidisciplinary, drawing upon expertise in areas such as computer and electrical engineering, neuroscience, and mathematics. Applicants are encouraged to develop collaborative relationships with scientists in the Air Force Research Laboratory (AFRL).
Another program goal is to deepen the scientific understanding of the sensory and sensorimotor processes that enable agile maneuvering and successful spatial navigation in natural flying organisms. Emphasis is on the discovery of fundamental mechanisms that could be emulated for the control of small, automated air vehicles, yet have no current analogue in engineered systems. Recent efforts have included investigations of information processing in wide field-of-view compound eye optics, receptor systems for linear and circular polarization sensing, and mathematical modeling of invertebrate sensorimotor control of path selection, obstacle avoidance and intercept/avoidance of moving targets. All of these areas link fundamental experimental science with neuromorphic or other mathematical implementations to generate and test hypotheses. Current efforts also include innovations in control science to explain and emulate complex behaviors, such as aerial foraging and swarm cohesion, as possible outcomes of simpler sensory-dominated behaviors with minimal cognitive support. As in the acoustic and psychoacoustic areas described above, applicants are encouraged to develop collaborations with AFRL scientists. However, consistent with AFOSR's basic science mission, all proposals to this program are evaluated for their potential transformative advance in scientific areas, not for their potential to effect technical improvements in current Air Force systems.
Dr. Patrick Bradshaw, AFOSR/RTE, (703) 588-8492
DSN 425-8492; FAX (703) 696-7360
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Test and Evaluation (T&E)
Program Description: The T&E program supports basic research which will build the foundation for future revolutionary capabilities that address the identified needs of the T&E Community. As new technologies emerge, the ability to test new capabilities as they are assimilated into applied Research and Development (R&D) is a critical part of the development process. The T&E Program sponsors basic research in areas that enable such testing and areas that allow the correct and comprehensive interpretation of test results. The current T&E Program encompasses five broadly-defined, overlapping thrust areas: Hypersonics, Aeroelasticity and Aerodynamics, Sensors and Electromagnetics, Information and Data Management and Fusion, and Enabling Materials. The Program is closely aligned with many other AFOSR program interests, but with special emphasis on aspects of basic research that lead to revolutionary advances in areas such as metrology and test science.
Basic Research Objectives: The T&E Program is closely engaged with technical experts at Air Force Developmental R&D Centers located at Edwards, Arnold, and Eglin Air Force Bases, who help advise the program on basic research objectives. Basic research in areas that advance the science of testing is broadly defined and spans mathematics as well as most disciplines in engineering and the physical sciences. Areas include:
- Novel measurement techniques, materials, and instruments that enable accurate, rapid, and reliable test data collection of physical, chemical, mechanical, and flow in extreme environments, such as those encountered during transonic flight, hypersonic flight, and the terminal portion of weapons engagement
- Accurate, fast, robust, integratable models of the aforementioned that reduce requirements to test or help provide greater understanding of test results
- Advanced algorithms and computational techniques that are applicable to new generations of computers, including massively parallel, quantum, and neuromorphic machine
- Advanced algorithms and test techniques that allow rapid and accurate assessment of devices and software to cyber vulnerability
- New processes and devices that increase bandwidth utilization and allow rapid, secure transfer of test data to control facilities during test, with special emphasis on telemetry
- Advanced mathematical techniques that improve design of experiment or facilitate confident comparison of similar but disparate tests
- Advanced models of test equipment and processes that improve test reliability and efficiency
- Basic research in other T&E technical areas that advances the science of test and contributes to the development of knowledge, skills, and abilities of the established or emerging AF T&E workforce.
Dr. Michael Kendra AFOSR/RTA (703) 588-0671
DSN 425-0671; FAX (703) 696-7320
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Turbulence and Transition
Program Description: The objective of the Turbulence and Transition portfolio is to develop the fundamental fluid physics knowledge base required for revolutionary advancements in a broad variety of future U.S. Air Force capabilities including energetically-efficient air and space systems, rapid global and regional response, and thermal/environmental management. Research supported by this portfolio seeks to characterize, model and exploit/control critical fluid dynamic phenomena through a balanced mixture of investments in experimental, numerical and theoretical efforts.
Basic Research Objectives: Innovative research is sought in all aspects of turbulent and transitional flows with particular interest in efforts that explore the dynamics and mechanisms of energy transfer within high-speed viscous flows. Topics of interest include, but are not limited to, the following:
- Laminar-turbulent stability, transition and turbulence in high-Mach number boundary layers, especially approaches leading to greater insight into surface heat transfer.
- Characterization and modeling of the impact of realistic surface conditions on transitional and turbulent flows in all speed regimes.
- Innovative experiments and numerical simulations that identify the underlying physics and potential control mechanisms for noise radiated from high-speed hot jets.
The behavior of viscous flows impacts the performance of all aerodynamic, propulsion, and environmental management systems and frequently determines the environment experienced by the system structure. The development of accurate methods for predicting the behavior of transitional and turbulent flows across a wide range of flow conditions will facilitate the design of future systems with optimized performance and energy-efficiency. Research areas of interest emphasize the characterization, prediction and control of high-speed fluid dynamic phenomena which will provide the scientific foundation for game-changing advancements in aerodynamics, environmental (thermal and acoustic) management, propulsion, and directed energy.
Researchers are strongly encouraged to submit short (max 6 pages) White papers to initiate discussion of a potential proposal topic prior to developing full proposals. White papers should briefly describe the proposed effort and illustrate how it will advance the current state-of-the-art; an approximate yearly cost for a three year effort should also be included. Researchers with White papers of significant interest will be invited to submit full proposals.
Dr. Rengasamy Ponnappan AFOSR/RTE (703) 696-9558
DSN 426-9558; FAX (703) 696-7320
E-mail: Turbulence@afosr.af.mil or firstname.lastname@example.org
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