Wall pressure beneath a transitional hypersonic boundary layer over an inclined straight circular cone

Dong, Siwei; Chen, Jianqiang; Yuan, Xianxu; Chen, Xi; Xu, Guangrui

doi:10.1186/s42774-020-00057-4

Cited by 17 publications

(6 citation statements)

References 36 publications

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“…Many studies have focused on the transition process of cross-flow vortices in 3-D boundary layers with help of numerical simulations. Boundary layer transition induced by roughness (Balakumar & Owens 2010;Choudhari, Li & Paredes 2017) or by random blowing and suction immediately downstream of the tip (Dong et al 2020) over a straight cone at non-zero angle of attack and Mach number 6 have been computed. Roughness can effectively trigger stationary cross-flow vortices, whereas blowing and suction tend to induce travelling cross-flow vortices.…”

Section: Introductionmentioning

confidence: 99%

Boundary layer transition and linear modal instabilities of hypersonic flow over a lifting body

Chen

Dong

et al. 2022

J. Fluid Mech.

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Boundary layer transition over a lifting body of 1.6 m length at $2^\circ$ angle of attack has been simulated at Mach 6 and a unit Reynolds number $1.0 \times 10^7$ m $^{-1}$ . The model geometry is the same as the Hypersonic Transition Research Vehicle designed by the China Aerodynamics Research and Development Center. Four distinct transitional regions are identified, i.e. windward vortex region, shoulder vortex region, windward cross-flow region and shoulder cross-flow region. Multi-dimensional linear stability analyses by solving the two-dimensional eigenvalue problem (spatial BiGlobal approach) and the plane-marching parabolized stability equations (PSE3D approach) are further carried out to uncover the dominant instabilities in the last three regions as well as the shoulder attachment-line region. The shoulder vortex is conducive to both inner and outer modes of shear-layer instability, of which the latter most likely trigger the vortex breakdown. A novel method is presented to substantially reduce the computational cost of BiGlobal and PSE3D in resolving the cross-flow instabilities in cross-flow regions. The peak frequencies of cross-flow modes lie between 15 and 45 kHz. Whereas oblique second Mack modes are marginally unstable in the windward cross-flow region, they could be strong enough to compete with the cross-flow modes in the shoulder cross-flow region. In the shoulder attachment-line region, there exists only one unstable mode of Mack instability, differing from previous studies that show a hierarchy of modes in the context of symmetrical attachment-line flows. Results of the numerical simulation and multi-dimensional stability analyses are compared when possible, showing a fair agreement between the two approaches and highlighting the necessity of considering non-parallel effects.

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Section: Introductionmentioning

confidence: 99%

Boundary layer transition and linear modal instabilities of hypersonic flow over a lifting body

Chen

Dong

et al. 2022

J. Fluid Mech.

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“…(2017) and Dong et al. (2020), showing that the second mode was easily destabilised both by stationary and travelling cross-flow vortices. Dong et al.…”

Section: Introductionmentioning

confidence: 95%

Boundary layer transition of hypersonic flow over a delta wing

Qiu,

Shi,

Zhu

et al. 2024

J. Fluid Mech.

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Cross-flow transition over a delta wing is systematically studied in a Mach 6.5 hypersonic wind tunnel, employing the Rayleigh scattering flow visualisation, high-speed schlieren and fast-response pressure sensors. Direct numerical simulations and analysis based on linear stability theory under the same flow conditions are applied to analyse the transition mechanism. Three unstable modes are identified: the travelling cross-flow instabilities, the second mode and the low-frequency waves. It is shown that the travelling cross-flow vortices first appear in the cross-flow region near the leading edge of the model. These vortices can modulate the mean profile of the flow, which benefits the growth of second mode. A phase-locked interaction mechanism transfers energy from the cross-flow instabilities to the high-frequency second mode, leading to amplification at the expense of the cross-flow instability. As the second mode grows to a critical amplitude, it triggers a $z$ -type secondary instability within a similar frequency range, which introduces secondary finger-like structures connecting to the cross-flow vortex. It is further found that the generation of these finger-like structures is related to the expansion and compression of the second mode. These finger vortices further evolve along the streamwise direction into low-frequency waves and corresponding hairpin-like structures that finally trigger turbulence. An interaction mechanism likely exists between the secondary instability and the low-frequency waves, since their phase speeds are approaching each other. These observations of the interaction mechanism are consistent with those of previous studies on hypersonic boundary layers (Zhang et al., Phys. Fluids, vol. 32 (7), 2020, 071702; Li et al., Phys. Fluids, vol. 32 (5), 2020, 051701).

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“…In order to take into account flow transition in CFD simulations, a lot of transition prediction methods have been proposed. These methods include: 1) stability-theory-based e N method, which is a physics-based method, modeling the evolution of perturbations inside boundary layers, such as the local LST (linear stability theory) [2]- [5], Bi-global LST [6], PSE (parabolized stability equations) method [7] [8] and direct numerical simulation method [9] [10]. 2) Transition criteria, which utilize empirical criteria derived from theoretical and experiment study, such as AHD (Arnal-Habiballah-Delcourt) criteria [11], Gleyzes criteria [12] and C1 criteria [13].…”

Section: Introductionmentioning

confidence: 99%

Application of surrogate models to stability analysis and transition prediction in hypersonic flows

Nie

Song

Han

et al. 2022

Preprint

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To increase the efficiency and convenience of stability-based transition prediction in flow simulations, simplified methods are introduced to substitute direct stability analyses for rapid disturbance growth prediction. For low-speed boundary layers, these methods are mainly established based on a self-similar assumption, which is not applicable to non-similar hypersonic flows over blunt cones. The objective of this article is to investigate the application of surrogate models to substitute linear stability analysis for non-similar flows on blunt cones, focused on input parameters for boundary-layer (BL) profile description. Firstly, correlations analyses between BL edge and profile parameters are conducted, along with a self-similar analysis and a discrete BL profile analysis, which present four groups of BL characteristic parameters. Secondly, using these parameters as inputs, surrogate models are built for disturbance growth prediction over an MF-1 blunt cone at flight experiments. Results show that, using 4 BL edge parameters and a BL shape factor {Ue, Te, ρe, ηe, H12} can achieve comparable accuracy with using 16 discrete BL profile parameters, which is also more precise than using merely self-similar parameters or BL edge parameters. Thirdly, the established surrogate models are validated in stability analysis and transition prediction over the MF-1 blunt cone at the moments of t =17s~22s in flight experiments. Compared with direct linear stability analyses, the mean relative error of predicted disturbance growth rates by surrogate models is 8.0% and the maximum relative error of N factor envelopes is 6.6%, which indicates the feasibility of using surrogate models to substitute stability analysis in transition prediction of non-similar flows over hypersonic boundary layers.

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Wall pressure beneath a transitional hypersonic boundary layer over an inclined straight circular cone

Cited by 17 publications

References 36 publications

Boundary layer transition and linear modal instabilities of hypersonic flow over a lifting body

Boundary layer transition and linear modal instabilities of hypersonic flow over a lifting body

Boundary layer transition of hypersonic flow over a delta wing

Application of surrogate models to stability analysis and transition prediction in hypersonic flows

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