PO 107‐1 Design, Development and Evaluation of a Noise Control Enclosure for a Model Jet Engine J. Black, J. Rinker, R. Yon, C. Holder, U.S. Air Force, Wright‐Patterson AFB, OH; J. Slagley, School of Aerospace Medicine, Wright‐ Patterson AFB, OH. Situation/problem: A cart‐mounted model jet engine used for educational demonstrations produced a sound pressure level (SPL) of 89.1 dB at a distance...

As functional (total care) products emerge in the jet engine industry, the need for product life-cycle models capable of definition and evaluation of life cycle properties increases, since functional products (FP) includes both hardware and service. Recent life-cycle models are intended for hardware products and mostly handle design and manufacturing knowledge. The aim of this article is to pre...

As functional (total care) products emerge in the jet engine industry, the need for product life-cycle models capable of definition and evaluation of life cycle properties increases, since functional products (FP) includes both hardware and service. Recent life-cycle models are intended for hardware products and mostly handle design and manufacturing knowledge. The aim of this article is to pre...

BACKGROUND Due to high sound pressure levels (SPLs), noise produced by jet planes may be harmful to hearing of people working in their proximity. The aim of this study was to assess the effects of exposure to jet engine noise on technical staff hearing. MATERIAL AND METHODS The study comprised 60 men, aged 24-50 years, employed in army as technical staff and exposed to jet engine noise for 6-...

one of the major problems facing the aircraft industry is the machining of the engine parts. amongst the numerous parts in a jet engine are intricate parts made of special alloys for high temperature service, namely nickel,chromium and titanium alloys. these alloys are usually very difficult to machine, which creates problems in this respect. the necessity of quality control in each stage of pr...

In this study an initial concept is described. This shows the possibility of connecting axially an ordinary jet engine, a ramjet engine and a scramjet engine. Furthermore rocket mode is also available in this design. The different modes can be changed by this integrated system as easily as the different modes, or nosecone stages can be changed by ordinary jet engines below and above the speed o...

There are at least two challenges that the jet engine noise community is currently facing. One challenge is due to existing engines that are being extended to higher power ratings without increasing the passive noise control treatment area. The second challenge comes about with the increasing trend to go to ultra-high bypass engines. This increases the importance of the fan tone noise and at th...

Several topics from the wide field of QCD studies in Deep-inelastic ep Scattering at HERA are addressed. They include QCD analyses of the inclusive cross section with the determination of α s and the proton gluon density from the F 2 scaling violations, and the determination of the longitudinal structure function F L. QCD analyses of inclusive jet and dijet data are also presented. Finally jet ...

The substructure of jets has been studied in terms of the jet shape and subjet multiplicity and these quantities used to tag gluonand quark-initiated jets. Cross sections are presented for gluonand quark-tagged jets which exhibit the expected behaviour of the underlying parton dynamics. The value of αs(MZ ) of αs(MZ ) = 0.1176 ± 0.0009(stat.) +0.0009 −0.0026 (exp.) −0.0072 (th.) was extracted f...

We construct the moduli space of r−jets at a point of Riemannian metrics on a smooth manifold. The construction is closely related to the problem of classification of jet metrics via differential invariants. The moduli space is proved to be a differentiable space which admits a finite canonical stratification into smooth manifolds. A complete study on the stratifica-tion of moduli spaces is car...