Modular Exhaust Design and Manufacturing Techniques for Build-to-Order Muffler Systems

Managing the acoustic signature of military vehicles can play a critical role in the safety of soldiers. Low-frequency sounds propagate through the atmosphere, resulting in unacceptable acoustic vehicle detection ranges, requiring relatively large silencer structures to mitigate. Currently, these requirements are met by using a custom muffler that is hand-assembled using low-volume prototyping manufacturing techniques. This method results in significant engineering and manufacturing time.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Design processes, Manufacturing processes, Noise, Mufflers, Military vehicles and equipment

Silicon Microsphere Fabrication

The efficiency and methodology of coupling light into microcavities has improved exponentially in the last decade. One such advancement is coupling light onto silicon microspheres. The material, size, and shape of a silicon microsphere are ideal for optical devices. Silicon microspheres are not the primary material used to fabricate microspheres for optical coupling because current methods used for microsphere fabrication cannot produce single-crystal silicon in the 16-μm scale, which is best for current optical technology.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Optics, Fabrication

Designing and Fabricating a Multiple-Decade Battery

There is a great need for energy sources that can power unattended sensors for more than a decade. Unattended sensors can be located in harsh and remote locations that are often dangerous for personnel maintenance and power source replacement. The power source must last the lifetime of the sensor. Unlike chemical batteries, the higher energy densities of radioisotopes allow the sensors to operate for infrastructure lifetimes (~150 years). Isotope batteries (iBATs) have the potential to become reliable, robust, and maintenance-free power sources for remote, long-term, low-power sensors. iBATs are different from chemical batteries because they are self-contained energy sources using radioisotope decay.

Posted in: Briefs, Aerospace, Defense, Manufacturing & Prototyping, Design processes, Batteries, Fabrication

Maximizing Thermal Cooling Efficiencies in High-Performance Processors

Despite the continuous development of new, higher performing processors, the thirst for increased embedded computing capability remains unquenched. In fact, it seems like Moore’s Law may have slowed when it comes to frequency but increased in terms of driving processor core and field programmable gate array (FPGA) LUTS counts. The previous need for fewer frequency increases has become a need for increased core counts, faster front side bus speeds, and greater support chip integration, all of which drive continually rising power requirements. Meeting these ever increasing "compute density escalations" while simultaneously maximizing thermal cooling efficiencies requires innovative packaging solutions.

Posted in: Articles, Aerospace, Defense, Computer software / hardware

Stand-Off Scanning and Pointing with Risley Prisms

With the ever increasing threat of improvised explosive devices, both in the military arena and the civilian realm, there is a growing demand for technologies with the ability to detect explosives and their precursors from a safe stand-off. While a wide variety of technologies have been investigated for this application, laser-based spectroscopic techniques designed to detect chemical traces on personnel, vehicles and other objects have garnered a lot of attention. These laser-based techniques include Raman spectroscopy, laser induced breakdown spectroscopy (LIBS), diffuse reflectance spectroscopy (DRS), and photothermal spectroscopy (PTS), among others. Laser-based approaches concentrate a large amount of power on a single target location, which enables reasonable signal-to-noise ratio (SNR) to be obtained despite the 1⁄R2 drop-off in return signal strength (where R represents stand-off distance).

Posted in: Articles, Aerospace, Defense, Optics

Getting It Right with Composites

"Composite design and analysis is a highly integrated activity,” said Chris Gear, Chief Technology Officer & Senior Technical Fellow for GKN Aerospace. He noted that how composite material is placed, how it moves, how it cures, and the quality and conformance of the product are all interrelated. All of these factors are considered in the final release of the data for manufacturing, according to him, aided by design-for-manufacturing (DFM).

Posted in: Articles, Aerospace, Defense, Design processes, Manufacturing processes, Composite materials

Regional and Bizjets Refined and Redefined

There is definitely a degree of overlap in the regional and business jet sectors, both in terms of airframes and the engines that power them. At the high end of the market are aircraft such as the Boeing 737 BBJ and Airbus A319 Corporate Jet, which typically carry up to a dozen VIP passengers in spacious luxury, but which in airline service carry around 130 passengers.

Posted in: Articles, Aerospace, Aviation, Defense, Aircraft structures, Avionics, Business and general aviation aircraft

Solutions for RF Power Amplifier Test

As wireless mobile devices grow in capability and complexity, the associated growth in power demand is driving new approaches to battery utilization and power efficiency. One of the single largest power consumers in a wireless handset is the RF Power Amplifier (PA) and as such, improved efficiency techniques like Envelope Tracking (ET) and Digital Pre-Distortion (DPD) are being increasingly utilized. The key implication for test engineers — whether in design, characterization, or manufacturing test — is that testing these devices with this additional capability can potentially drive up both test cost and overall test time. This article discusses various approaches to maximizing test equipment utilization and reducing test times for such component RF PAs and front-end modules.

Posted in: Articles, Aerospace, Defense, Amplifiers, Test procedures

Air-Ground Communications System Aims to Make Flying Safer

Reliance on old-fashioned radio contact by pilots and vulnerable tracking systems is still high, but satellites are set to change sky safety, thanks to international collaboration. The European Space Agency’s Iris program is looking to satellites to make aviation safer through modern communications. Worldwide digital data links via satellite, offering much higher capacity, will become the standard for cockpit crews, with voice communications kept as backup.

Posted in: Articles, Aerospace, Aviation, Defense, Satellite communications

Altair Optimizes 3D-Printed Structures for Complex, Lightweight Designs

Altair expects to better support the use of additive manufacturing (AM), or 3D printing, by releasing new OptiStruct solver capabilities for topology optimization. The company claims this new technology is the first tool developed specifically for designers of lattice structures.

Posted in: Technology Update, Defense, Design processes, Manufacturing processes