Acoustic loading beneath hypersonic transitional and turbulent boundary layers

Ritos, Konstantinos; Drikakis, Dimitris; Kokkinakis, Ioannis

doi:10.1016/j.jsv.2018.10.021

Cited by 23 publications

(32 citation statements)

References 41 publications

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“…The results presented here are from simulations performed at Mach 6 and turbulence intensity of the free-stream velocity T u = 3%. Further details about the free-stream and boundary conditions can be found in [20].…”

Section: Hypersonic Flow Over a Flat Platementioning

confidence: 99%

“…Beresh et al [8] has proposed a value of 0.009 for the incompressible limit based on an estimated extension of the measured pressure spectra. According to the simulations in [20], a value of 0.008 is suggested for flows up to Mach 8. The theoretical model with the suggested value (dashed black line in inset (a) of Figure 6) shows good agreement with the calculated values in the areas of the domain where the flow is attached and the pressure gradients are low.…”

Section: Hypersonic Flow Over a Compression/expansion Rampmentioning

confidence: 99%

“…For instance, Görtler-like vortices have been observed at Mach 7 around a compression ramp and it was suggested that these vortices are responsible for the low-frequency motion of the shock wave [12]. Studies of hypersonic TBLs have also been published [17,18]; however investigations of the effects of transitional or turbulent boundary layers on acoustic loading are scarce [19,20].…”

Section: Introductionmentioning

confidence: 99%

“…This will allow to showcase similarities and differences between the various hypersonic boundary layers in the context of acoustic loading. The flow results for the STBLI case have been previously compared with available Direct Numerical Simulations (DNS) and experimental data [21], while the results for the transitional boundary layer presented here are based on a previous more detailed study by the authors [20].…”

Section: Introductionmentioning

confidence: 99%

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Computational aeroacoustics beneath high speed transitional and turbulent boundary layers

et al. 2020

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This paper concerns a study of pressure fluctuations beneath hypersonic shockwave turbulent boundary layer interactions and the associated acoustic loading on a compression/expansion ramp. We have employed high-order implicit large eddy simulations and conducted simulations at Mach 7.2. The spectral analysis of the pressure fluctuations at various locations of the compression/expansion ramp are compared with the spectra calculated beneath a hypersonic transitional boundary layer. Similarities and differences between the two hypersonic boundary layers, in the context of acoustic loading, are drawn. Extremely high values of pressure fluctuations are recorded after the shock re-attachement where the maximum pressure gradients are also observed, indicating that acoustic loading is correlated with areas of high pressure gradients. Finally, we show the impact of the boundary layer state (attached flow, turbulence bursts, recirculations, shock oscillations, shock re-attachment and expansion fans) on the frequency spectrum of the pressure fluctuations.

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Section: Hypersonic Flow Over a Flat Platementioning

confidence: 99%

Section: Hypersonic Flow Over a Compression/expansion Rampmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computational aeroacoustics beneath high speed transitional and turbulent boundary layers

et al. 2020

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“…In this paper, the qualitative accuracy of several WPSM is assessed for supersonic and hypersonic TBL. WPSM are compared with data that has been obtained from implicit Large Eddy Simulations (iLES) [10,11], which can be considered as an under-resolved Direct Numerical Simulation (DNS). Furthermore, compressibility corrections are proposed that significantly improve the accuracy of spectra models.…”

Section: Introductionmentioning

confidence: 99%

Wall-pressure spectra models for supersonic and hypersonic turbulent boundary layers

Ritos

Drikakis

Kokkinakis

2019

Journal of Sound and Vibration

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This paper presents an investigation of pressure fluctuations spectra beneath supersonic and hypersonic turbulent boundary layers at zero pressure gradient. High-order implicit Large Eddy Simulations have been used to provide numerical data for assessing existing models and further improving their qualitative accuracy in predicting wall-pressure spectra. Several different models have been investigated and it is shown that existing models fail to capture the correct behaviour of pressure fluctuations in supersonic and hypersonic boundary layers across a broad range of frequencies. The models have been modified by introducing compressibility corrections. The modified models are validated against implicit Large Eddy Simulations, Direct Numerical Simulations, and experimental data. The qualitative accuracy of the models is discussed and the most promising model is identified.

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