Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.
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http://dx.doi.org/10.1080/10473289.2005.10464651 | DOI Listing |
Rev Sci Instrum
December 2024
College of Intelligent Manufacturing, Long Dong University, Qingyang, Gansu 745000, China.
The deflector jet pressure servo valve (DJPSV), a critical component of the aircraft brake servo system, requires a precise foundational model for performance analysis, optimization, and enhancement. However, the complexity of the jet process within the V-groove of the deflector plate presents challenges for accurate mathematical modeling. To address this issue, the paper takes the DJPSV as the research object, carries out detailed mathematical modeling of its components, analyzes the influencing factors of the performance of the key component-the front stage-and optimizes the design of the key factors.
View Article and Find Full Text PDFAerosp Med Hum Perform
November 2024
Background: Ejection seats are designed to be a lifesaving device for aircrew in emergencies. Modern ejection seats are widely prevalent in fighter and bomber aircraft and are occasionally associated with acceleration injury from axial loading (Gz) during the catapult phase of ejection, limb flail injury due to windblast, or parachute landing fall, especially if the ejection is outside of the seat's performance envelope.
Case Report: We present the first known case in the medical literature of a military pilot who survived a low-altitude, high-angulation (>90° of bank angle) ejection where the pilot's ejection seat parachute did not deploy due to contact with the ground before completion of the ejection sequence.
Antonie Van Leeuwenhoek
November 2024
Department of Biology, Faculty of Science, Istanbul University, 34134, Vezneciler, Istanbul, Türkiye.
A novel gram-stain-indeterminate, rod-shaped, endospore-forming, motile, aerobic bacterium, designated JETA1-E2, was isolated from aircraft fuel Jet A1 sample. The strain showed high pairwise similarity values of partial 16S rRNA gene sequences to Sphingomonas paucimobilis (MT367853) (99.42%), Sphingomonas sanguinis (MF319771) (99.
View Article and Find Full Text PDFCommun Eng
November 2024
Mechanical Engineering Department, Tennessee Tech University, Cookeville, TN, USA.
PLoS One
October 2024
Department of administration, Chengdu Industrial Research Institute Branch of China Mobile Communication Group Co Ltd, Chengdu, China.
Jet fuel plays a crucial role as an essential energy source in aerospace and aviation operations. The recent increase in fuel prices has presented airlines with the new challenge of managing jet fuel costs to ensure consistent cash flow and minimize operational uncertainties. The conventional risk prediction models used by airlines often assume that risks are normally distributed according to the classical Central Limit Theorem, which can lead to under-hedging.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!