Deterministic Flow Field and Flow Structure Model of Asymmetric Vortices over Slender Body

Xueying, Deng; Wang, Yankui; Chen, X.

doi:10.2514/6.2003-5475

Cited by 6 publications

(9 citation statements)

References 11 publications

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“…This characteristic of the sectional side force distributions is in good agreement with the knowledge obtained in a previous experimental study. 3,20) Therefore, the side force is comparable value between with the large bump and the medium bump instead of stronger asymmetricity in the vortex structure with the large bump. As the results, the relationship between the side force and the bump height is nonlinear.…”

Section: Effect Of Bump Heightmentioning

confidence: 98%

Numerical Investigation of Asymmetric Separation Vortices over Slender Body by RANS/LES Hybrid Simulation

Inaba

Nishida

Nonomura

et al. 2012

AEROSPACE TECHNOLOGY JAPAN

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We analyze the asymmetric vortices in the flow over a slender body at high angle of attack by numerical simulations aiming a proportional control of the side forces generated by vortices with a device such as dielectric barrier discharge (DBD) plasma actuator. With regard to the computational method, Reynolds averaged Navier Stokes/large-eddy simulation hybrid method is adopted with high-order compact spatial difference scheme. The grid convergence analysis is firstly conducted and the results show that the computational grid adopted in this study is fine enough for qualitative discussion. The total number of the grid point is 411 million points. Then, the effects of bump height on flow fields and aerodynamic characteristics are discussed. Note that bump is added near the body apex to simulate the symmetry-breaking imperfection. As a higher bump is adopted, stronger asymmetry is observed in the flow fields. On the other hand, side-force has nonlinearity with the bump height.

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Section: Effect Of Bump Heightmentioning

confidence: 98%

Numerical Investigation of Asymmetric Separation Vortices over Slender Body by RANS/LES Hybrid Simulation

Inaba

Nishida

Nonomura

et al. 2012

AEROSPACE TECHNOLOGY JAPAN

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“…In order to obtain a repeatable and reproducible test results of an asymmetric vortex flow over a slender model and corresponding side force from tests in wind tunnels. Chen et al [42], Deng et al [43], Chen [44], Deng et al [45][46][47] have completed a series of studies. They used a simple micro-grit as an artificial perturbation to attach on the model tip.…”

Section: Determinacy Of Asymmetric Vortex Flow and Repeatability Withmentioning

confidence: 99%

“…In order to improve this forebody vortex active control characteristics at high angles of attack with bistable state behavior, Deng et al [43,[45][46][47]53,55] have studied and explored systematically the behaviors of forebody asymmetric vortices with artificial perturbation and then developed a new active control technique in which a micro-bleed with single small hole of diameter 0.5 mm at model nose was used as artificial variable strength micro-perturbation. Their results from that control technique showed that when the artificial micro-perturbation with bleed momentum C µ = 0 (in this case just small hole plays an artificial perturbation) on the model nose tip is rotated in one cycle, the asymmetric vortices flow pattern in bistable state will switch over in two cycles.…”

Section: Active Control Of Asymmetric Vortex Flow With Nose Perturbationmentioning

confidence: 99%

Recent progress on the study of asymmetric vortex flow over slender bodies

Xueying

Tian

et al. 2008

Acta Mech Sin

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The investigations of forebody vortex flow and its flow control have great importance in both academic field and engineering application areas. A large number of papers and many review papers have been published. However in this research field of forebody asymmetric vortices, three problems such as tip perturbation effect, Reynolds number effect and flow instability are less studied and thus not understood completely. So many researches are still working on the issues in recent years. The present paper attempts to provide a review of recent research progress on first two problems. The first problem is mainly concerned with how the vortex flow evolves after tip perturbation; how to solve the problem of repeatability and reproducibility of wind tunnel testing data; how to develop a conception of active flow control technique with tip perturbation based on the study of vortex flow response to tip perturbation. For the second problem one is mainly concerned that how the asymmetric vortices are developed with the increase of Reynolds number; how to classify the vortex flow patterns in different Reynolds number regimes; how to develop an appropriate boundary layer transition technique to simulate flows at high Reynolds number in the convention wind tunnels. Finally, some important questions that deserve answers are proposed in the concluding remarks.

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“…Through arranging nose bleeds, Bernhardt et al [12] affirmed the existence of the spatial instability. Most recently, through mounting a triangle metal block near nose apex, Deng et al [13] achieved deterministic flow patterns, and pointed out that the additional certain artificial perturbation located near nose apex could even eliminate the flow uncertainty induced by the randomness of perturbations produced in physical-model machining.…”

Section: Introductionmentioning

confidence: 98%

“…For answering the puzzles, some researchers [11][12][13][14] have put forward the idea of designedly appending certain artificial perturbations (such as minute geometric bumps, bleeds, suctions, etc) near nose apex, and some attempts have been conducted. Through setting up a retractable tenuous wire or a fixed minute geometric bump near nose apex, Degani et al [11] obtained repeatable flow fields, and inferred that the origin characterizing the flow asymmetry was consistent with a convective-type of instability existing in original symmetric flow fields.…”

Section: Introductionmentioning

confidence: 99%

Influence of nose-perturbation location on behavior of vortical flow around slender body at high incidence

Guan

Wang

et al. 2009

Sci. China Ser. E-Technol. Sci.

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Response of the vortical flow around a slender body of revolution at high incidence to the shift of a single nose perturbation was investigated systematically using numerical methods. A minute geometric bump was employed to act as the nose perturbation, and all computations were performed for subsonic flows at incidence of 50°. The computational results show that the vortical flow is more sensitive to the perturbation located axially closer to the nose apex of a slender body. With perturbation shifting axially downstream away from nose apex, there is a critical axial location appearing. The vortical flow is less sensitive to the perturbation located axially closer to the critical axial location; when perturbation traverses axially around the critical axial location, the vortical flow switches between opposite asymmetric patterns. The eventual influence of perturbation axial location on the vortical flow lies on both its relative locations to nose apex and the critical axial location. The vortical flow is more sensitive to the perturbation located circumferentially farther away from the fore-and-aft symmetric plane of a slender body, and just the asymmetrically-located perturbation can provoke the vortical flow to asymmetry. With perturbation shifting circumferentially in sequence, the vortical flow varies by degrees in manner of a single periodicity. A convective-type of instability existing in the flow field is responsible for the influence of nose perturbation on the vortical flow.slender body of revolution, high-incidence aerodynamics, asymmetric vortical flow, nose perturbation, critical location

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Deterministic Flow Field and Flow Structure Model of Asymmetric Vortices over Slender Body

Cited by 6 publications

References 11 publications

Numerical Investigation of Asymmetric Separation Vortices over Slender Body by RANS/LES Hybrid Simulation

Numerical Investigation of Asymmetric Separation Vortices over Slender Body by RANS/LES Hybrid Simulation

Recent progress on the study of asymmetric vortex flow over slender bodies

Influence of nose-perturbation location on behavior of vortical flow around slender body at high incidence

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