Aerodynamic Development of a Radial Compressor for a 10-kw Turboalternator

Author(s):  
Colin Rodgers

The aerodynamic development of a small high-speed radial compressor for the US Army 10-kw turboalternator is discussed, including initial performance deficiencies arising from blade contour discrepancies. Design performance requirements were attained by correcting these discrepancies and subsequently were exceeded with further geometry refinements. Aerodynamic testing included an investigation concerning the effect of shroud axial clearance on compressor performance and showed that abradable shrouds are desirable for small compressors.

1977 ◽  
Vol 21 (3) ◽  
pp. 262-266 ◽  
Author(s):  
Michael G. Sanders ◽  
Ronald R. Simmons ◽  
Mark A. Hofmann ◽  
J. Nicholas DeBonis

The emphasis on aviator workload has been of primary concern to the US Army aviation community since the incorporation of low altitude terrain flight techniques into the helicopter tactics repertory. Since navigation has been a particularly acute problem at low altitudes, this project examined the visual workload of the navigator/copilot during terrain flight (nap-of-the-earth, contour and low level) in a UH-1H helicopter. Visual performance was measured via a modified NAC Eye Mark Recorder used in conjunction with a LO-CAM high speed camera. This technique provided the means to objectively record and analyze the navigator's visual performance through the examination of: (1) visual time inside the cockpit on flight and engine instruments, (2) time inside the cockpit on the map or other navigation aids, and (3) time outside the cockpit in various windscreen sectors. A visual free time task (Strother, 1973) was utilized to determine the amount of visual time the navigator had available, during flight over the prescribed course, for a nonflight related task. The data indicate that the navigator's normal workload was demanding; the visual free time task was utilized only 3% of the total time. The data also indicate that the duty of navigating required 92.2% of the copilot's total visual time while the engine and flight instruments were utilized only 4% of the time. These data are discussed in relation to the copilot's specified duties.


Author(s):  
S U Lee ◽  
D Robb ◽  
C Besant

A radial compressor has been designed at Imperial College for cooling a high-speed generator (HSG) coupled directly to a small gas turbine engine to produce 100kW electric power. The compressor has a significant influence on the overall dynamics of the generator. Therefore, it is designed to be lightweight for rotor-dynamic reasons together with reasonable aerodynamic efficiency. An experimental rig for the compressor performance testing was also designed. In order to operate this rig safely, it is very important to be able to predict and analyse its dynamic behaviour. For this purpose, a systematic procedure was used to develop a finite element (FE) model to predict natural frequencies under operating conditions. In the procedure, the relationship between FE analyses, modal analyses and results of a running test are established. Vibration analyses of the compressor rig using the proposed procedure are carried out. Finally, the results of computations and experiments for the rig are presented and compared.


Author(s):  
Brian Marquis ◽  
Jon LeBlanc ◽  
Ali Tajaddini

In the US, increasing passenger speeds to improve trip time usually involves increasing speeds through curves. Increasing speeds through curves will increase the lateral force exerted on track during curving, thus requiring more intensive track maintenance to maintain safety. These issues and other performance requirements including ride quality and vehicle stability, can be addressed through careful truck design. Existing high-speed rail equipment, and in particular their bogies, are better suited to track conditions in Europe or Japan, in which premium tracks with little curvature are dedicated for high-speed service. The Federal Railroad Administration has been conducting parametric simulation studies that examine the performance of rail vehicles at high speeds (greater than 90 mph) and at high cant deficiency (greater than 5 inches). The purpose of these analyses is to evaluate the performance of representative vehicle designs subject to different combinations of track geometry variations, such as short warp and alinement.


2020 ◽  
pp. 304-312

Background: Insult to the brain, whether from trauma or other etiologies, can have a devastating effect on an individual. Symptoms can be many and varied, depending on the location and extent of damage. This presentation can be a challenge to the optometrist charged with treating the sequelae of this event as multiple functional components of the visual system can be affected. Case Report: This paper describes the diagnosis and subsequent ophthalmic management of an acquired brain injury in a 22 year old male on active duty in the US Army. After developing acute neurological symptoms, the patient was diagnosed with a pilocytic astrocytoma of the cerebellum. Emergent neurosurgery to treat the neoplasm resulted in iatrogenic cranial nerve palsies and a hemispheric syndrome. Over the next 18 months, he was managed by a series of providers, including a strabismus surgeon, until presenting to our clinic. Lenses, prism, and in-office and out-of-office neurooptometric rehabilitation therapy were utilized to improve his functioning and make progress towards his goals. Conclusions: Pilocytic astrocytomas are the most common primary brain tumors, and the vast majority are benign with excellent surgical prognosis. Although the most common site is the cerebellum, the visual pathway is also frequently affected. If the eye or visual system is affected, optometrists have the ability to drastically improve quality of life with neuro-optometric rehabilitation.


Author(s):  
D.B. Izyumov ◽  
E.L. Kondratyuk

The article discusses issues related to the development and use of training means and facilities in order to improve the level of training of US Army personnel. An overview of the main simulators used in the US Armed Forces at present is given, and the prospects for the development of the United States in this area are presented.


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