Study of an engine flow diverter system for a large scale ejector powered aircraft model

Requirements were established for a conceptual design study to analyze and design an engine flow diverter system and to include accommodations for an ejector system in an existing 3/4 scale fighter model equipped with YJ-79 engines. Model constraints were identified and cost-effective limited modification was proposed to accept the ejectors, ducting and flow diverter valves. Complete system performance was calculated and a versatile computer program capable of analyzing any ejector system was developed

System data communication structures for active-control transport aircraft, volume 2

The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems

System data communication structures for active-control transport aircraft, volume 1

Candidate data communication techniques are identified, including dedicated links, local buses, broadcast buses, multiplex buses, and mesh networks. The design methodology for mesh networks is then discussed, including network topology and node architecture. Several concepts of power distribution are reviewed, including current limiting and mesh networks for power. The technology issues of packaging, transmission media, and lightning are addressed, and, finally, the analysis tools developed to aid in the communication design process are described. There are special tools to analyze the reliability and connectivity of networks and more general reliability analysis tools for all types of systems

X-ray scattering from surfaces: discrete and continuous components of roughness

Incoherent surface scattering yields a statistical description of the surface, due to the ensemble averaging over many independently sampled volumes. Depending on the state of the surface and direction of the scattering vector relative to the surface normal, the height distribution is discrete, continuous, or a combination of the two. We present a treatment for the influence of multimodal surface height distributions on Crystal Truncation Rod scattering. The effects of a multimodal height distribution are especially evident during in situ monitoring of layer-by-layer thin-film growth via Pulsed Laser Deposition. We model the total height distribution as a convolution of discrete and continuous components, resulting in a broadly applicable parameterization of surface roughness which can be applied to other scattering probes, such as electrons and neutrons. Convolution of such distributions could potentially be applied to interface or chemical scattering. Here we find that this analysis describes accurately our experimental studies of SrTiO3 annealing and homoepitaxial growth.Comment: 15 pages, 7 figure

The design of mixed-use virtual auditory displays: Recent findings with a dual-task paradigm

Presented at the 10th International Conference on Auditory Display (ICAD2004)In the third of an ongoing series of exploratory sound information display studies, we augmented a dual task with a mixed-use auditory display designed to provide relevant alert information for each task. The tasks entail a continuous tracking activity and a series of intermittent classification decisions that, in the present study, were presented on separate monitors that were roughly 90\,^{\circ} apart. Using a 2-by-3 design that manipulated both the use of sound in each task and where sounds for the decision task were positioned, the following principal questions were addressed: Can tracking performance be improved with a varying auditory alert tied to error? To what degree do listeners use virtual auditory deixis as a cue for improving decision reaction times? Can a previous finding involving participants' use of sound offsets (cessations) be repeated? And, last, are there performance consequences when auditory displays for separate tasks are combined? Respectively, we found that: Tracking performance as measured by RMS error was not improved and was apparently negatively affected by the use of our auditory design. Listener's use of even limited virtual auditory deixis is robust, but it is probably also sensitive to the degree it is coincident with the location of corresponding visual stimuli in the task environment. On the basis of manually collected head movement data, listeners do make opportunistic use of sound offsets. And, finally, a significant interaction, as measured by average participant reaction time, was observed between the auditory display used for one task and the manipulation of the degree of auditory deixis encoded in the auditory display used for the other task in our paradigm