Woods B.K.S.,University of Maryland University College |
Kothera C.S.,Techno-Sciences, Inc. |
Wereley N.M.,University of Maryland University College
Journal of Intelligent Material Systems and Structures | Year: 2011
An active trailing edge flap system, actuated utilizing Pneumatic Artificial Muscles (PAMs), is developed in this study. PAMs were chosen as the actuation method because of several attractive properties, including: high specific work and power output, an expendable operating fluid (air), and robustness. Because of their performance, PAM are a potential enabling technology for a variety of next-generation aerospace systems. The actuation system developed here is sized for a full-scale active rotor system for a Bell 407 scale helicopter. This system is designed to produce large Trailing Edge Flap (TEF) deflections (±20°) at the main rotor rotation frequency (1rev-1) to create large amplitude thrust variations that enable primary control of the helicopter. Additionally, the TEF actuation system is designed to produce smaller magnitude deflections at higher frequencies, up to 5rev-1 (N+1rev-1), to provide vibration mitigation capabilities. The PAMs are mounted antagonistically in the root of each blade. A bell crank and linkage system transfers the force and motion of these actuators to a trailing edge flap on the outboard portion of the rotor. A reduced span wind tunnel test model of this system was fabricated and tested in the Glenn L. Martin Wind Tunnel at the University of Maryland at wind speeds of up to M=0.3, which is the maximum test wind speed of the facility. The test article consisted of a 1.55m long outboard section of a Bell 407 rotor blade cantilevered from the base of the tunnel with a 0.86m, 15% chord plain flap that was driven by the PAM actuation system. Testing over a wide range of aerodynamic conditions and actuation parameters demonstrated the considerable control authority and bandwidth of the system at the aerodynamic load levels available in the tunnel. Comparison of quasi-static experimental results shows good agreement with analytical predictions made using a simple system model. © The Author(s), 2011. Source
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 599.84K | Year: 2012
The primary goal of this project is to develop a set of design tools for the development of next generation power and load management strategies and devices to integrate distributed generation and load management into modern vehicle power systems. It is intended to facilitate design and operation of power systems with distributed resources, integrating multiple generation alternatives, accommodating all operational modes and load demands and even component failures. The proposed power management systems will enable efficient, optimal and fault tolerant operation with appropriate cost-benefit tradeoffs and provide a secure information gateway to enable flexibility and adaptability to changing operational needs. We also propose to consider new distribution system topologies and new protection/isolation strategies to enhance overall stability and reliability The proposed effort is based on a new analysis and design technology that enables inclusion of both discrete and dynamical components (allowing incorporation of widely ranging time scales in modern Shipboard Power Systems) which enables the design of controllers that respond to discrete events such as operational mode change, load level of a component/subsystem or availability of generation resource, while respecting the inherent dynamic constraints of the system. The methodology and computer tools we propose will not only enable the design of new distribution system topologies and strategies for the system operators but also controllers capable of autonomous action if the time scale of the situation requires it. These basic ideas and some of the associated computational tools have been previously developed by Techno-Sciences, Inc. under contracts and grants from ONR, DOE, NAVSEA and NASA. In the Phase I effort we have developed a concept of operation, developed an optimization scenario and demonstrated the results on a developed benchmark simulation of the DDG 51 architecture with a Hybrid Electric Drive to demonstrate how the tools will be used in a prototype form. All pertinent component models were created and implemented in the proposed framework. We have also created the operational interface and data-logging tools to achieve a first level of validation. In the Phase I option effort, we can achieve limited hardware in the loop testing and In Phase II, we expect to expand the design tools for such a class of systems. We will also transition the tools to first level of verification to low power hardware in the loop tests and begin the transition to a land based test facility for more significant testing by the end of Phase II performance period. The software will be modular and easily extensible to accommodate the requirements of supervision and reconfiguration of such power systems.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 749.99K | Year: 2012
High technology small business Techno-Sciences, Inc. in partnership with Submarine Emergency Position Indicating Radio Beacon (SEPIRB) manufacturer Ultra Electronic Ocean Systems Inc. proposes the development of next generation, self powered SEPIRB. Many innovations in the design of the beacon and powering are proposed including improved hardware, various software configurations appropriate for the next generation COSPAS-SARSAT system, as well as, a unique set of energy harvesting mechanisms that will help the device achieve long shelf life. The beacon will be easy to maintain and can be deployed using standard operating procedures. In Phase I, low power electronic beacon board was manufactured and tested and energy harvesting solutions were investigated. Phase II focuses on development of prototypes and initial testing. Later phases will involve launch testing and integration into the fleet.
Purekar A.S.,Techno-Sciences, Inc. |
Pines D.J.,University of Maryland University College
Journal of Intelligent Material Systems and Structures | Year: 2010
Damage detection in composite laminated panels using Lamb waves is demonstrated with an innovative use of a sensor array and processing algorithm. Two models were developed to characterize the Lamb wave propagation properties of orthotropic panels. Predictions of the dispersion relations were made for a fiber-reinforced composite laminate. Experiments were conducted to empirically characterize the wave propagation behavior in a manufactured laminate. Piezoelectric patches were used as sensors and actuators in the experiments. Comparisons were made between analytical predictions and experimental results, which demonstrate that the higher order model captured essential wave propagation behavior at frequencies of interest. Sensor arrays and associated processing were used for wavenumber decomposition and filtering of the Lamb wave modes. Composite laminates were manufactured with an embedded defect to simulate inter-ply delamination. Experiments were conducted to detect the presence of delamination damage in a composite laminate. © The Author(s), 2010. Source
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase I | Award Amount: 149.88K | Year: 2011
Rotors and their associated dynamic components operate in high-cycle and environmentally harsh conditions. Accurate rotor load predictions are crucial part of rotor analysis and design. Lag damping poses a challenge for rotor load analysis due to the difficulty of incorporating lag damper effects into comprehensive rotor analysis. The key challenge in effectively predicting the lead-lag motions and resulting rotor loads is the lack of a high fidelity lag damper model. A high fidelity lag damper model that can predict damping forces over the operational range of a helicopter will benefit future rotor designs.