Jet lag is due to the misalignment of the internal circadian clock(s) with external time cues. For short stopovers (1–2 days) adapting the circadian system is not advised, and at present immediate circadian adaptation is virtually impossible. The use of short-term measures such as judicious naps, caffeine and short acting hypnotics to maintain alertness and sleep is preferred. For intermediate ...

Vector acoustic intensity provides both the direction and magnitude of energy flow at the probe location and is, hence, more informative than acoustic pressure measurements. However, this important quantity has seen little application previously in aeroacoustics. In the present work, an intensity probe, consisting of four microphones, captured the radiated field to the sideline and aft of a tet...

SUMMARY Wind-tunnel tests have been made to assess the aerodynamic potential of an overwing installation for fan-jet engines on a typlcal modern transport aeroplane. Low-speed tests on a complete model with free-flow nacelles and tests at higher speed on a partial model incorporating a blown jet are described; it is concluded that the lift-dependent drag associated with such an installation wou...

Experimental results are presented on a method that eliminatesMach waves from the exhaust of supersonic jets and,hence, that removes a strong component of supersonic jet noise. Eliminationis achievedby surrounding the jet with an annular stream at prescribed velocity and temperature so that all turbulent motions become intrinsically subsonic. No mechanical suppressors are used. Implementation o...

performance analysis of jet engines in various environmental conditions is important and is the first step in the design of such engines. in this paper, the performance of a typical turboprop engine was modeled in the commercial software gasturb10 and the obtained results are validated at three flight regimes take off, military and 100% normal using engine test results. performance analysis of ...

Published near-field analyses of full-scale jet noise are limited, and the application of observed laboratory scale phenomena to full-scale jets is not well understood. To obtain a greater understanding of the connection between radiated noise and source characteristics in full-scale, heated, supersonic jets produced by military aircraft, acoustical measurements were made in the geometric near ...

In a scramjet, the fuel can be used to cool down the engine walls. The thermal decomposition of the jet fuel changes the reacting mixture before its combustion. A numerical study of the pyrolysis of norbornane, a jet fuel surrogate, has been performed. Rate constants of some sensitive reaction channels have been calculated by means of quantum chemical calculations at the CBS-QB3 level of theory...

The paper presents a type of observer based on reduced to minimum set of engine parameters measured directly: turbine-compressor rotational speed, engine inlet air pressure and temperature and atmospheric pressure. Results of application in analysis of data recorded during engine operation in non-stationary states of SO-3 engine (powering TS-11 Iskra aircraft) are presented. Possibilities of th...

We report the jet width profile of of the nearby (∼30 Mpc) AGN NGC 4261 for both the approaching jet and the counter jet at radial distances ranging from ∼103–109 Schwarzschild radius (RS) from the central engine. Our Very Large Array (VLA) and Very Long Baseline Array (VLBA) observations reveal that the jets maintain a conical structure on both sides over the range 103–109 RS without any struc...