Effects of Roughness on Hypersonic Boundary-Layer Transition

Schneider, Steven P.

doi:10.2514/6.2007-305

Cited by 52 publications

(49 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The hypersonic boundary-layer transition can be significantly affected by the existence of surface roughness (Reda 2002, Schneider 2008a). Owing to the complex geometry of the embedded roughness, it is difficult to generate body-fitted structured grids for three-dimensional flow fields with roughness.…”

Section: High-order Cut-cell Methodsmentioning

confidence: 99%

Direct Numerical Simulation on the Receptivity, Instability, and Transition of Hypersonic Boundary Layers

Zhong

Wang

2012

Annu. Rev. Fluid Mech.

299

118

View full text Add to dashboard Cite

The prediction of the laminar-turbulent transition of boundary layers is critically important to the development of hypersonic vehicles because the transition has a first-order impact on aerodynamic heating, drag, and vehicle operation. The success of transition prediction relies on a fundamental understanding of the relevant physical mechanisms. In the 20 years since the review by Kleiser & Zang (1991) on the direct numerical simulation (DNS) of the boundary-layer transition, significant progress has been made on DNS in the hypersonic flow regime and in the spatial DNS approach. Many high-order shock-capturing and shock-fitting finite-difference methods have been developed and extensively applied to numerical simulations of the hypersonic boundary-layer transition. DNS has become a powerful research tool and has led to discoveries of new transition mechanisms. This article reviews the recent progress of DNS on hypersonic boundary-layer receptivity, instability, and transition. The current status and future directions are also presented. 527 Annu. Rev. Fluid Mech. 2012.44:527-561. Downloaded from www.annualreviews.org by University of California -Los Angeles (Young Research Library) on 01/04/12. For personal use only. Receptivity mechanisms Transient growth B Increasing disturbance level Figure 1Paths to boundary-layer transition with respect to the disturbance amplitude. Path A, three-stage-transition mechanism in a weak-disturbance environment; path B, three-stage-transition mechanism including weak transient growth; paths C and D, transition mechanisms with strong transient growth; path E, bypass transition to very strong disturbance. Figure taken from Reshotko (

show abstract

Section: High-order Cut-cell Methodsmentioning

confidence: 99%

Direct Numerical Simulation on the Receptivity, Instability, and Transition of Hypersonic Boundary Layers

Zhong

Wang

2012

Annu. Rev. Fluid Mech.

299

118

View full text Add to dashboard Cite

show abstract

“…Most of the studies involving surface imperfections looked at isolated roughness elements of different shapes (Fong et al [15,16,17,18], Duan et al [19], Park and Park [20], Mortensen and Zhong [36], Bountin et al [21]). A comprehensive review about the effect of different roughness elements on hypersonic boundary layers can be found in Schneider [22].…”

Section: Introductionmentioning

confidence: 99%

Assessment of the Impact of Two-Dimensional Wall Deformation Shape on High-Speed Boundary-Layer Disturbances

et al. 2018

View full text Add to dashboard Cite

Previous experimental and numerical studies showed that two-dimensional roughness elements can stabilize disturbances inside a hypersonic boundary layer, and eventually delay the transition onset. The objective of this paper is to evaluate the response of disturbances propagating inside a high-speed boundary layer to various two-dimensional surface deformations of different shapes. We perform an assessment of the impact of various 2D surface non-uniformities, such as backward or forward steps, combinations of backward and forward steps, wavy surfaces, surface dips, and surface humps. Disturbances inside a Mach 5.92 flat-plate boundary layer are excited using periodic wall blowing and suction at an upstream location. The numerical tools consist of a high-accurate numerical algorithm solving for the unsteady, compressible form of the Navier-Stokes equations in curvilinear coordinates. Results show that all types of surface non-uniformities are able to reduce the amplitude of boundary layer disturbances to a certain degree. The amount of disturbance energy reduction is related to the type of pressure gradients that are posed by the deformation (adverse or favorable). A possible cause (among others) of the disturbance energy reduction inside the boundary layer is presumed to be the result of a partial deviation of the kinetic energy to the external flow, along the discontinuity that is generated by the wall deformation. arXiv:1807.02197v1 [physics.flu-dyn] 5 Jul 2018 Khokhlov [26,27], Sakaue et al. [29], Fedorov [30]). In some of these studies, it was found that acoustic waves are very effective in exciting disturbances inside the boundary layer with amplitudes that become much larger than those in the free-stream, but this happens only above some critical Reynolds number as in the incompressible regime. Other studies (Fedorov and Khokhlov [26,27], Sakaue et al. [29], Fedorov [30]) were concerned about the generation of the first and second modes in the vicinity of the leading edge. The effect of all types of waves, i.e. slow and fast acoustic waves, vorticity waves and entropy waves, on supersonic boundary layers was studied and reported in a suite of papers by Balakumar [31,32,33]. The generation and the evolution of three-dimensional disturbances induced by slow and fast acoustic disturbances and isolated roughness elements in a supersonic boundary layer over flat plates and wedges were numerically investigated by solving the full three-dimensional Navier-Stokes equations. It was found that instability waves are generated within one wavelength of the acoustic wave from the leading edge.Previous experimental and numerical studies (Holloway and Sterrett [34], Fujii [35], Fong et al. [15, 16, 17, 18], Duan et al. [19], Park and Park [20], Mortensen and Zhong [36]) showed evidence that twodimensional roughness elements can reduce the amplitude of disturbances inside high-speed boundary layers. Holloway and Sterrett [34], for example, carried out early experiments on flat plate boundary layer disturbed by roughness ele...

show abstract

“…A value of the roughness Reynolds number of Re k ' 10 is recommended to maintain laminar boundary layers on the contoured nozzle walls ( [68], p. 4). Here, Re k is a Reynolds number based on the roughness height k and conditions in the undisturbed laminar boundary layer at the roughness height [13]. This value of Re k is much lower than that used elsewhere, presumably because small streamwise vortices from the roughness can amplify via the Görtler instability [13].…”

Section: Mach-35 Quiet Tunnelmentioning

confidence: 98%

“…Here, Re k is a Reynolds number based on the roughness height k and conditions in the undisturbed laminar boundary layer at the roughness height [13]. This value of Re k is much lower than that used elsewhere, presumably because small streamwise vortices from the roughness can amplify via the Görtler instability [13]. Considerable effort is also required to maintain extreme cleanliness on these highly polished surfaces; earlier difficulties with maintaining laminar nozzle-wall boundary layers at high unit Reynolds numbers were now attributed not only to roughness but also to insufficient nozzle-cleaning procedures ([68], p. 3).…”

Section: Mach-35 Quiet Tunnelmentioning

confidence: 99%

“…Although the measurements in these facilities are obviously the reason for developing them, these measurements are described only on occasion, in passing, because the paper is already a long one. It is assumed that the reader is already familiar with the general area of hypersonic instability and transition (for example, see [9][10][11][12][13]). In particular, the reader is assumed to be familiar with the semiempirical e N method for estimating transition onset by using the linear amplification of a given instability wave by a factor of e N from the beginning of instability to the observed or predicted transition location [14].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Development of Hypersonic Quiet Tunnels

Schneider

2008

Journal of Spacecraft and Rockets

216

View full text Add to dashboard Cite

Since then, he has focused on high-speed boundary-layer transition, developing facilities and instrumentation for detailed measurements under quiet-flow conditions. A $1 million 9.5-in. Mach-6 quiet-flow Ludwieg tube was completed in 2001 and achieved high Reynolds number quiet flow in 2006. He was promoted to professor, School of Aeronautics and Astronautics, in 2004, and has written seven review articles on hypersonic transition. He is an Associate Fellow of AIAA.

show abstract

Effects of Roughness on Hypersonic Boundary-Layer Transition

Cited by 52 publications

References 45 publications

Direct Numerical Simulation on the Receptivity, Instability, and Transition of Hypersonic Boundary Layers

Direct Numerical Simulation on the Receptivity, Instability, and Transition of Hypersonic Boundary Layers

Assessment of the Impact of Two-Dimensional Wall Deformation Shape on High-Speed Boundary-Layer Disturbances

Development of Hypersonic Quiet Tunnels

Contact Info

Product

Resources

About