Power Management for the Electric Taxiing System Incorporating the More Electric Architecture

With airlines increasingly directing their attention to operating costs and environmental initiatives, the More Electric Architecture for Aircraft and Propulsion (MEAAP) is emerging as a viable solution for improved performance and ecofriendly aircraft operations. An electric taxiing system was developed that does not require the use of jet engines or the auxiliary power unit (APU) during taxiing, either from the departure gate to takeoff, or from landing to the arrival gate.

Posted in: Briefs, Aerospace, Defense, Electronics & Computers, Architecture, Power electronics, Electric drives

Simultaneous Vibration Suppression and Energy Harvesting

The goal of this work was to investigate the concept of using harvested energy to directly control the vibration response of flexible aerospace systems. Small, lightweight, flexible micro air vehicles (MAVs) operate near flutter, providing both harvesting opportunities and vibration suppression requirements. The possibility that the ambient energy might be harnessed and recycled to provide energy to mitigate the vibrations through various control laws was investigated. The goal was to integrate harvesting, storage, control, and computation into one multifunctional structure.

Posted in: Briefs, Physical Sciences, Vibration, Unmanned aerial vehicles

Cascading Failures in Coupled Distributed Power Grids and Communication Networks

Emerging distributed power grid systems will integrate tightly coupled networks, namely a power grid and a communication network, to provide distributed power monitoring and control. While distributing power monitoring and control away from a central site enhances the robustness of the power grid to multiple, dispersed failures and attacks, such communication-based distributed control schemes can introduce complex cascading failure scenarios in the face of large-scale weapons of mass destruction (WMD) attacks.

Posted in: Briefs, Physical Sciences, Telecommunications, Electric power grid, Hazards and emergency management

Implementing Interconnected Generation in Future Civil Aircraft

In addition to providing thrust, the engines on conventional civil jet airliners generate power for onboard systems and ancillary loads in the form of pneumatic, hydraulic, and electrical power. There is a move to begin replacing mechanically, hydraulically, and pneumatically powered aircraft systems with electrical equivalents, towards the ultimate goal of achieving the All-Electric Aircraft (AEA).

Posted in: Briefs, Electronics & Computers, Electrical systems, Business and general aviation aircraft

Electronics Take Charge

Electronic controls are slowly transforming aircraft engines of all types, bringing improved fuel consumption, improved efficiency, and more power. As the functionality of control units for jet engines increases, digital management is also adding more capabilities for helicopters and small piston engines.

Posted in: Articles, Aerospace, Defense, Electronics & Computers, Computer simulation, Computer software / hardware, Electronic control systems, Electronic control units, Jet engines

Optically Transparent EMI Shielding for Defense and Aerospace Applications

Modern electronic devices and computing equipment are often integrated with wireless capabilities which utilize multi-bands for high speed communication, as well as high speed circuits and high definition graphical displays that operate at a wide range of frequencies. As such, hardware systems are becoming increasingly complex, resulting in products that are highly sensitive to electromagnetic interference (EMI). The vulnerability to EMI is further heightened when multiple components are packed close together within the device due to space, size and weight constraints. As such, traditional shielding methods that employ materials like thick metal Faraday cages are not always practical due to their heavy weight and bulkiness. Despite its complexity, managing this interference and increasing the resilience of components, interconnects and subsystems within the device is crucial to ensuring reliability and functionality.

Posted in: Articles, Aerospace, Defense, Materials, Avionics, Electromagnetic compatibility, Electronic equipment, Optics, Displays, Military aircraft

Pumped Two-Phase Cooling for Thermal Management of High Heat Flux Electronics

Pumped two-phase cooling provides a compact, low pumping power option for thermal management in high heat flux applications (300-500W/cm2). Compared to single-phase convection, significantly higher heat transfer coefficients can be achieved at substantially lower flowrates. Two-phase cooling also provides a high degree of isothermality, which is important in many applications such as lasers whose emission wavelengths are temperature-dependent.

Posted in: Articles, Aerospace, Defense, Materials, Electronic equipment, Thermal management, Coatings Colorants and Finishes

Thermal Simulation and Testing of Expanded Metal Foils for Lightning Protection

With the implementation of major aircraft structures fabricated from carbon fiber reinforced plastic materials, lightning protection has become a more complicated issue for designers and engineers to solve.

Cracking of coatings and surface layers is evident on a variety of structures including buildings, automobiles, and aircraft. In some situations, the appearance of the coated or painted surface is degraded and the aesthetic appeal is lessened. However, in others, such as composite aircraft structures, paint cracking is both aesthetically undesirable and potentially deleterious from the electromagnetic effects aspect.

Posted in: Articles, Aerospace, Defense, Materials, Test & Measurement, Computer simulation, Coatings Colorants and Finishes, Composite materials, Lightning protection, Thermal testing

Software Defined Radio Enables Flexible Communications for NASA

Communication is key to just about any endeavor. NASA’s ability to update and modify communication capabilities to reflect the latest upgrades without impacts to mission time or a trip back to Earth ensures optimal communication continues. In-orbit reconfiguration for spacecraft radios and systems, including those on the International Space Station, is the goal behind NASA’s Space Communications and Navigation (SCaN) Testbed.

From its invention until now, the radio has undergone some mighty technological advances. Conventional or legacy radios are not programmable; they are designed for one fixed configuration. They are built to produce a single waveform at a specified frequency. Conventional radios often also have limited tuning options and fixed data rates. While some conventional radios carry multiple types of data, they are incapable of adapting to new waveforms. To make changes on these legacy radios, the radio would physically need to be changed. Once a radio is out in space, that task becomes nearly impossible to accomplish. These limitations created a need for improved communication in space.

Posted in: Articles, Aerospace, Defense, Computer software / hardware, Radio equipment, Satellite communications, Test equipment and instrumentation

Automated Testing of Advanced, High-Performance, Point-to-Multipoint Radio Systems

In 2008, 4RF Communications started development of a new range of radio products to augment their existing point-to-point, long-range wireless link product. Used by oil, gas, and utility companies for monitoring and control applications, the Aprisa SR is a point-to-multipoint Smart Supervisory Control and Data Acquisition (SCADA) radio operating in the 400 to 470-MHz licensed spectrum band with a 12.5-kHz channel size and narrowband 9.6-kbps capacity. The Aprisa SR is designed to address the key concerns facing the industry, such as the need for enhanced security, the need to efficiently handle the increasing complexity of SCADA networks, and the evolution to an IP-based and smart grid infrastructure.

Posted in: Articles, Aerospace, Defense, Radio equipment, Data acquisition