Characteristics of helicopter engine exhaust through scaled experiments using stereoscopic particle image velocimetry
| Autor: | Zhi Wen Lee, Bing Feng Ng, Zhen Wei Teo, Tze How New, Wai Hou Wong |
|---|---|
| Přispěvatelé: | School of Mechanical and Aerospace Engineering |
| Rok vydání: | 2020 |
| Předmět: |
Mechanical Engineering
Acoustics Aerospace Engineering 02 engineering and technology Aerodynamics 01 natural sciences 010305 fluids & plasmas Vortex Stereoscopic particle image velocimetry Footprint (electronics) 020303 mechanical engineering & transports 0203 mechanical engineering Particle image velocimetry Fuselage 0103 physical sciences Mechanical engineering [Engineering] Environmental science Counter rotating Scale model |
| Zdroj: | Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering. 235:1091-1104 |
| ISSN: | 2041-3025 0954-4100 |
| DOI: | 10.1177/0954410020966471 |
| Popis: | Helicopter engines are often mounted atop the fuselage to keep the aircraft footprint small and optimal for operations. As a result, hot gases produced by the engines may inadvertently impinge upon the tail boom or dissipate inefficiently that compromises on operation safety. In this study, a scaled fuselage model with a hot air blower was used to simulate hot exhaust gases. The velocity field immediately outside the exhaust port was measured through stereoscopic particle image velocimetry to capture the trajectory and flow behaviour of the gases. Two cases were considered: freestream to exhaust velocity ratios of 0 (no freestream velocity) and 0.46 (co-flowing free stream), respectively. The formation of a counter-rotating vortex pair was detected for both cases but were opposite in the rotational sense. For the case without freestream, the plume formed into a small “kidney” shape, before expanding and dissipating downstream. For the case with freestream, the plume formed into a slenderer and more elongated “reversed-C” shape as compared to the case without freestream. It also retained its shape further downstream and maintained its relative position. These observations on the trajectory and shape of plume provide basis to understanding the nature and interaction of the plume with its surroundings. Accepted version This work was supported by Leonardo-Finmeccanica Helicopter division. |
| Databáze: | OpenAIRE |
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