Experimental cold-flow evaluation of a ram air cooled plug nozzle concept for afterburning turbojet engines

A concept for plug nozzles cooled by inlet ram air is presented. Experimental data obtained with a small scale model, 21.59-cm (8.5-in.) diameter, in a static altitude facility demonstrated high thrust performance and excellent pumping characteristics. Tests were made at nozzle pressure ratios simulating supersonic cruise and takeoff conditions. Effect of plug size, outer shroud length, and varying amounts of secondary flow were investigated

Cold-flow performance of several variations of a ram-air-cooled plug nozzle for supersonic-cruise aircraft

Experimental data were obtained with a 21.59 cm (8.5 in.) diameter cold-flow model in a static altitude facility to determine the thrust and pumping characteristics of several variations of a ram-air-cooled plug nozzle. Tests were conducted over a range of nozzle pressure ratios simulating supersonic cruise and takeoff conditions. Primary throat area was also varied to simulate afterburner on and off. Effect of plug size, outer shroud length, primary nozzle geometry, and varying amounts of secondary flow were investigated. At a supersonic cruise pressure ratio of 27, nozzle efficiencies were 99.7 percent for the best configurations

Tau-aggregation inhibitor therapy for Alzheimer's disease

Article Accepted Date: 9 December 2013 Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.Peer reviewedPublisher PD

Stellar spectropolarimetry with HiVIS: Herbig Ae/Be stars, circumstellar environments and optical pumping

The polarization of light across spectral lines contains information about the circumstellar material on small spatial scales. Many models relate the circumstellar environment to observable polarization changes across spectral lines. However, measuring signals at the 0.1% level requires a very careful control of systematic effects. We have recently built a high-resolution spectropolarimeter for the HiVIS spectrograph on the 3.67m AEOS telescope and have obtained a large number of high precision spectropolarimetric observations of Herbig Ae/Be, Classical Be and other stars. The detected linear polarization varies from our typical detection threshold near 0.1% up to 2%. This polarization effect is generally not coincident with the H-alpha emission peak but is detected only in the absorptive part of the line profile and varies with the absorption. These detections are largely inconsistent with the traditional scattering models and inspired a new explanation of their polarization. We developed a new spectropolarimetric model and argue that polarization in absorption is evidence of optical pumping. We argue that, while scattering theory fits many Be and emission-line star observations, this new theory has much more potential to explain polarization-in-absorption as seen in Herbig Ae/Be and other stellar systems. This thesis presents a large spectropolarimetric study that combines new instrumentation, custom processing software, thorough calibrations, cross-instrument comparisons, a massive observing campaign on many targets, comparison of current theories on multiple objects and finally the creation of a new theory.Comment: U.Hawaii Ph.D Dissertation - May 2008 - Kuhn, Herbig, Meech, Williams & Lucey. Reformatted to 2-column article. Original format at http://www.ifa.hawaii.edu/~dmh/pubs.htm