Non-Adiabatic Surface Effects on Step-Induced Boundary-Layer Transition

Costantini, Marco; Risius, Steffen; Klein, Christian

doi:10.1007/s10494-018-9913-7

Cited by 7 publications

(14 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In those previous studies, only one junction was present on the model upper surface, instead of the three junctions (two upstream of the bump) on the configuration investigated in this work, and the number of turbulent wedges arising at that only one junction at larger Reynolds numbers was significantly smaller than that observed here. Therefore, chord Reynolds numbers larger than those examined in the present work could be considered in Costantini et al (2016), Costantini (2016) and Costantini et al (2018); at those Reynolds numbers, transition was shown to occur over the model upper surface even at the largest examined Hartree parameters. Another finding of those previous investigations was that, for the examined clean configuration, the transition Reynolds number was essentially independent of the chord Reynolds number.…”

Section: Discussionmentioning

confidence: 85%

“…Note that in several cases, such as those shown in Figure 6a and Figure 13cd, the boundary layer remained laminar over the whole clean (i.e., bump-free) surface. In these cases, the reference transition Reynolds numbers Re xT,0 for a nominally smooth surface were taken from the results of previous studies (Costantini et al (2016), Costantini (2016) and Costantini et al (2018)), in which the same model contour had been examined at larger chord Reynolds numbers. This was possible because the values of Re xT,0 obtained in different investigations were verified to be in agreement for the test conditions at which transition occurred over the model surface (see Sec.…”

Section: Discussionmentioning

confidence: 99%

“…The model surface temperature range was T w = 284.5-287.5 K. (The temperatures T w and T aw were evaluated at x/c = 15 %, where the boundary layer was laminar at all examined test conditions.) As discussed in Arnal (1992), Schlichting and Gersten (2000), Costantini et al (2016), Costantini (2016) and Costantini et al (2018), a non-adiabatic surface has an effect on boundary-layer stability and transition in flows over smooth surfaces. In Costantini (2016) and Costantini et al (2018), a non-adiabatic surface was also found to have an influence on transition induced by forward-facing steps, at least up to a certain value of the non-dimensional step parameters.…”

Section: Test Parameters and Experimental Conditionsmentioning

confidence: 93%

“…As discussed in Arnal (1992), Schlichting and Gersten (2000), Costantini et al (2016), Costantini (2016) and Costantini et al (2018), a non-adiabatic surface has an effect on boundary-layer stability and transition in flows over smooth surfaces. In Costantini (2016) and Costantini et al (2018), a non-adiabatic surface was also found to have an influence on transition induced by forward-facing steps, at least up to a certain value of the non-dimensional step parameters. In Al-Maaitah et al (1990), a variation in the wall temperature ratio T w /T aw was shown to have an impact on boundary-layer stability even in the presence of a bump.…”

Section: Test Parameters and Experimental Conditionsmentioning

confidence: 93%

See 3 more Smart Citations

Experimental study of bump effects on boundary-layer transition in compressible high Reynolds number flow

Costantini¹,

Risius²,

Koch³

et al. 2019

Experimental Thermal and Fluid Science

View full text Add to dashboard Cite

The influence of surface bumps on boundary-layer transition was experimentally investigated in the present work. The experiments were conducted in a (quasi-) two-dimensional flow at low to high subsonic Mach numbers and chord Reynolds numbers up to 10 million in the low-turbulence Cryogenic Ludwieg-Tube Göttingen. Various streamwise pressure gradients relevant for natural laminar flow surfaces were examined. Quasi-two-dimensional bumps, with a sinusoidal shape in the streamwise direction, fixed length and three different heights, were installed on a two-dimensional flat-plate model. The model was equipped with temperature-sensitive paint for non-intrusive transition detection and with pressure taps for the measurement of the surface pressure distributions. Boundary-layer transition was shown to occur at a more upstream location with increasing bump height-to-length ratio. This was mainly due to the local adverse pressure gradient on the downstream side of the bump, which was particularly pronounced in the case of the bump with the largest height-to-length ratio, thereby inducing boundary-layer separation (as verified via oil-film visualizations). In the case of the bump with the smallest height-to-length ratio, bumpinduced transition was found to be dependent on global pressure gradient, Mach number and Reynolds number; however, the influence of these parameters on transition induced by bumps with larger height-tolength ratios was significantly reduced. The sensitivity of boundary-layer transition to the effect of the bumps was shown to be more pronounced with stronger global flow acceleration and at smaller Mach numbers.

show abstract

Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

Section: Test Parameters and Experimental Conditionsmentioning

confidence: 93%

Section: Test Parameters and Experimental Conditionsmentioning

confidence: 93%

See 2 more Smart Citations

Experimental study of bump effects on boundary-layer transition in compressible high Reynolds number flow

Costantini¹,

Risius²,

Koch³

et al. 2019

Experimental Thermal and Fluid Science

View full text Add to dashboard Cite

show abstract

“…In these experiments, FFS showed a less detrimental effect on the boundary layer flow than BFS for the same step height and wind tunnel conditions. Furthermore, Costantini, Risius & Klein (2015, 2018) experimentally investigated the effect of pressure gradient, surface temperature and Mach number on the transition behaviour of FFS on an unswept wing model in a cryogenic Ludwieg-tube wind tunnel.…”

Section: Introductionmentioning

confidence: 99%