Measurements and stability calculations of the disturbance growth in an unstable three-dimensional boundary layer

A brief review of laminar flow control techniques is given and a strategy for achieving laminarization for transonic transport aircraft is discussed. A review of some flight-test results on swept-wing transition is presented. It is also shown that polished leading edges can create large regions of laminar flow because the flight environment is relatively turbulence free and the surface finish reduces the initial amplitude of the stationary crossflow vortex.

show abstract

“…with a 3.8 mm average peak-to-peak. In this case transition moved forward to [25][26][27][28][29][30] …”

Section: (C) Laminarization Results With a Painted Surfacementioning

confidence: 99%

“…Stationary crossflow waves often show evidence of strong nonlinear effects [28][29][30][31][32][33][34][35]. Because the wavefronts are fixed with respect to the model and are nearly aligned with the local potential-flow direction (i.e.…”

Section: (D) Three-dimensional Boundary Layers: Crossflow Wavesmentioning

confidence: 99%

Passive control of transition in three-dimensional boundary layers, with emphasis on discrete roughness elements

Saric

Carpenter

Reed

2011

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…Most studies concentrate on the regimes with pure or significant steady crossflow vortex, because the low free-stream turbulence conditions are assumed in free flight and the steady crossflow vortex is easier to track. More detailed discussions can be found in Müller & Bippes [1], Bippes & Müller [2], Bippes [3], Bippes, Müller & Wanger [4] and Reed & Saric [5].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the secondary instability of the incompressible flows over a swept wing

Xiao

2011

Sci. China Phys. Mech. Astron.

View full text Add to dashboard Cite

The crossflow instability of a three-dimensional (3-D) boundary layer is an important factor which affects the transition over a swept-wing. In this report, the primary instability of the incompressible flow over a swept wing is investigated by solving nonlinear parabolized stability equations (NPSE). The Floquet theory is applied to study the dependence of the secondary and high-frequency instabilities on curvature, Reynolds number and angle of swept (AOS). The computational results show that the curvature in the present case has no significant effect on the secondary instabilities. It is generally believed that the secondary instability growth rate increases with the magnitude of the nonlinear mode of crossflow vortex. But, at a certain state, when the Reynolds number is 3.2 million, we find that the secondary instability growth rate becomes smaller even when the magnitude of the nonlinear mode of the crossflow vortex is larger. The effect of the angle of swept at 35, 45 and 55 degrees, respectively, is also studied in the framework of the secondary linear stability theory. Larger angles of swept tend to decrease the spanwise spacing of the crossflow vortices, which correspondingly helps the stimulation of 'z' mode. crossflow instability, secondary instability, curvature, angle of swept PACS: 47.20.Lz

show abstract

“…More detailed discussions can be referred to Müller and Bippes [1], Bippes and Müller [2], Bippes [3], Bippes et al [4], and Reed and Saric [5].…”

Section: Introductionmentioning

confidence: 99%

Secondary instability control of compressible flow by suction for a swept wing

Xiao

2011

Sci. China Phys. Mech. Astron.

View full text Add to dashboard Cite

The crossflow instability of a three-dimensional boundary layer is a main factor affecting the transition around the swept-wing. The three-dimensional boundary layer flow affected by the saturated crossflow vortex is very sensitive to the high frequency disturbances, which foreshadows that the swept wing flow transition will happen. The primary instability of the compressible flow over a swept wing is investigated with nonlinear parabolized stability equations (NPSE). The Floquet theory is then applied to the analysis of the influence of localized steady suction on the secondary instability of crossflow vortex. The results show that suction can significantly suppress the growth of the crossflow mode as well as the secondary instability modes. boundary layer suction, crossflow instability, secondary instability PACS: 47.20.Lz

show abstract

Measurements and stability calculations of the disturbance growth in an unstable three-dimensional boundary layer

Cited by 42 publications

References 5 publications

Passive control of transition in three-dimensional boundary layers, with emphasis on discrete roughness elements

Passive control of transition in three-dimensional boundary layers, with emphasis on discrete roughness elements

Analysis of the secondary instability of the incompressible flows over a swept wing

Secondary instability control of compressible flow by suction for a swept wing

Contact Info

Product

Resources

About