Ray-theory predictions of the sound radiated from realistic engine intakes

Kempton, A. J.; Smith, Michael J.

doi:10.2514/6.1981-1982

Cited by 4 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work, an inviscid mean flow model is used. In the literature, nearly all published works related to engine inlet radiation use an inviscid model, regardless 170 C. K. W. Tam, S. A. Parrish, E. Envia and E. W. Chien of whether an analytical approach is used, such as in the works of Lansing (1970), Homicz & Lordi (1975), Kempton & Smith (1982) and Dougherty (1996), or a computational approach is used, such as in the works of Baumeister & Horowitz (1984), Eversman et al (1985), Roy & Eversman (1995), Ozyoruk & Long (1996), Astley et al (2002), Ozyoruk (2002), Zhang et al (2002), Ozyoruk et al (2004), Premo et al (2007) and Achunche et al (2009). In reality, a viscous/turbulent boundary layer would develop on the surface of the engine casing.…”

Section: Diffraction and Refractionmentioning

confidence: 99%

“…Acoustic radiation from jet engine inlets has been studied experimentally by Heidmann, Saule & McArdle (1980), Preisser et al (1985), Heidelberg (2002), Premo & Joppa (2002), Woodward et al (2002), Herkes, Olser & Uellenberg (2006), Yu et al (2006), Callender et al (2007) and Lan et al (2007), analytically by Lansing (1970), Homicz & Lordi (1975), Kempton & Smith (1982) and Dougherty (1996), and computationally by Baumeister & Horowitz (1984), Eversman et al (1985), Parrett & Eversman (1986), Roy & Eversman (1995), Ozyoruk & Long (1996), Ahuja, Ozyoruk & Long (2000), Astley et al (2002), Ozyoruk (2002), Zhang et al (2002), Ozyoruk et al (2004), and Achunche et al (2009) in the past. † Email address for correspondence: tam@math.fsu.edu Physical processes influencing acoustic radiation from jet engine inlets These studies provide a variety of useful and interesting information.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Physical processes influencing acoustic radiation from jet engine inlets

et al. 2013

View full text Add to dashboard Cite

Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream-propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic duct mode to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of a duct mode by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number, duct mode frequency, azimuthal mode number and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition versus one in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

show abstract

Section: Diffraction and Refractionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physical processes influencing acoustic radiation from jet engine inlets

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Acoustic radiation from jet engine inlets has been studied experimentally [1][2][3][4][5][6][7][8][9] , analytically [10][11][12][13] and computationally [14][15][16][17][18][19][20][21][22][23][24][25][26] by a number of investigators in the past. These studies provide a variety of useful and interesting information.…”

Section: Introductionmentioning

confidence: 99%

Physics of Acoustic Radiation from Jet Engine Inlets

Tam

Parrish

Envia

et al. 2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

View full text Add to dashboard Cite

Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test (SDT) is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic wave to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of sound waves by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number and duct mode frequency, azimuthal mode number, and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition and in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

show abstract