Test & Measurement

Simulating and Analyzing Flow for an Air-to-Air Refueling System

Long-range bombers may have missions halfway around the world. Fighter jets may have to stay in the air longer than their relatively small fuel tanks will allow, or may find they have exhausted their fuel unexpectedly, such as during supersonic flight or evasive maneuvers. In these situations, large tanker aircraft are deployed that carry sufficient fuel to refill several smaller aircraft in a single mission (Figure 1). The task of injecting volatile jet fuel from one aircraft to another while both are moving at high speed and altitude is fraught with risk.

Posted in: Articles, Aerospace, Test & Measurement

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Using High Bandwidth Oscilloscopes to Analyze Radar and Electronic Warfare Systems

Whether for multi-channel analysis, or for wider analysis bandwidth in a measurement, high bandwidth oscilloscopes offer an alternative to traditional spectrum and signal analyzers for both pulsed RF aerospace/defense and I/Q vector modulated communications application measurements. Signals with spectral content beyond 1 or 2 GHz are now being created to support the higher resolution requirements in radar systems and to move the vast amounts of information in new communications systems.

Posted in: Articles, Aerospace, Communications, Wireless, Defense, RF & Microwave Electronics, Test & Measurement

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Developing and Testing Electronic Control Units for Electric Drives

Air framers are looking to build more eco-friendly and economical aircraft, and they are turning to electric drives. One growing trend is to build more electrical aircraft by replacing pneumatic and hydraulic systems with electric actuators. Electric drives, therefore, will play an important role in the aircraft of the future. This paper examines the current state of technology for developing and testing electric drives.

Posted in: White Papers, White Papers, Aeronautics, Electronics, Electronics & Computers, Test & Measurement

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The Effect of Substrate Emissivity on the Spectral Emission of a Hot-Gas Overlayer

Analytic model demonstrates the impact of emitted background radiation on the molecular gas spectrum.Recently, in operando optical investigations of high temperature solid oxide electrochemical cells (SOECs) have gained significant traction with several research groups motivated by a need to directly correlate electrochemical performances of SOECs with their associated and complex electrode processes. These techniques (including Raman spectroscopy, ambient x-ray photoelectron spectroscopy, near-infrared thermal imaging, and Fourier transform infrared emission spectroscopy) have demonstrated a significant advantage over traditional, indirect experimental methods by providing direct, non-invasive information in real time along with high temporal, spatial, and/or molecular resolution.

Posted in: Briefs, TSP, Aerospace, Defense, Test & Measurement

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Experimental Setup to Assess Blast and Penetration- Induced Secondary Debris in a Military Operations in Urban Terrain (MOUT) Environment

Testing demonstrates effects of blast debris on personnel protective equipment.As part of Project Agreement on Military Operations in Urban Terrain (MOUT), the US Army Research Laboratory’s (ARL’s) Explosives Effects Branch supported a series of experiments conducted in Meppen, Germany (DEU), to understand loading on personnel protective equipment (PPE) produced during urban weapon attacks. These experiments were conducted by detonating an explosive charge placed on a brick wall to create secondary debris that would impact the US-designed collection medium.

Posted in: Briefs, TSP, Aerospace, Defense, Test & Measurement

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Non-Contact Circuit for Real-Time Electric and Magnetic Field Measurements

Sensor can measure electric and magnetic fields simultaneously.An energized electric power cable generates low-frequency electric and magnetic fields that are related to the voltages and currents. Especially at wavelengths λ>>d, where d is the distance away from an energized conductor and λ is the signal wavelength, we can extract electrical information with quasi-static near-field electric and magnetic field theory and the Principle of Superposition.

Posted in: Briefs, TSP, Aerospace, Defense, Test & Measurement

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Damping Measurement for Wafer-Level Packaged MEMS Acceleration Sensors

Two methods were developed for mechanical analysis of MEMS sensors. Army Research Laboratory, Adelphi, Maryland Microelectromechanical system (MEMS) three-axis acceleration threshold sensors have been developed to measure acceleration threshold levels using voltage switching when the threshold is reached. Determining damping coefficients is important for categorizing how each threshold sensor or switch operates. Switches with different damping coefficients result in different mechanical impedances and response times. Analytical and numerical methods to model damping coefficient values based on empirical data are needed to characterize three-axis acceleration sensors; traditional methods use the displacement of an underdamped system to calculate the damping ratio.

Posted in: Briefs, Defense, MEMs, Sensors, Measuring Instruments, Sensors and actuators, Switches

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