Transition and crossflow instability
Environmental Influences on Crossflow Instability
... 4. High Turbulence Level: Tu = 0.19% To complete this set of experiments, the turbulence level is raised to 0.19% and boundary-layer measurements are made through x/c = 0.375. The average transition location for ...
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Forcing of the primary and secondary crossflow instability
... The fluctuations of the travelling wave with a frequency around 250Hz are located close to the wall in between two vortex structures as shown in Figure 32D. In these locations the contours of the time-averaged velocity U ...
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Numerical Investigation of Crossflow Instability on the HIFiRE-5
... Boundary-Layer Instability Mechanisms Stability theory, as it pertains to laminar shear flows, describes the way pertur- bations behave when subjected to the mean state of a ...
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Crossflow Instability on a Wedge-Cone at Mach 3.5
... the crossflow generated by a slender wedge-cone model at zero angle of attack to study supersonic crossflow dominated boundary-layer ...stationary crossflow pattern on the model as predicted from the ...
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Crossflow Instability on a Yawed Cone at Mach 6
... Department of Aerospace Engineering, Texas A&M University, College Station, TX 77843, USA Abstract Boundary-layer measurements were performed in a Mach 6, low-disturbance wind tunnel on a 7 ◦ cone at 5.6 ◦ angle of ...
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Effect of Freestream Turbulence on Roughness-induced Crossflow Instability
... Jacobs et al. 8 for the first time followed the methodology proposed by Grosch et al. 9 to synthesize freestream turbulence. Their method allowed to skip over the simulation of the far-field and the leading edge. Later, ...
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Computational Investigation of Sensitivity of the Crossflow Instability to Two-Dimensional Surface Imperfections
... disturbances have a spanwise wavelengths on the order of ten step-heights, and that these modes have an energy growth of order 80 · 10 3 at Re h = 500. It should be noted that in general little to nothing is said ...
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The Effect of Forward-Facing Steps on Stationary Crossflow Instability Growth and Breakdown
... stationary crossflow amplitude can cause a previ- ously subcritical step height to become ...stationary crossflow amplitude followed a similar growth and decay pattern to the larger step ...early ...
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On the effect of discrete roughness on the growth of crossflow instability in very low turbulence environment
... All these previous studies on DREs, however, have focused on highly idealised roughness configurations arranged on a single array. This type of morphology is not representative of the real wing-skin roughness (e.g. due ...
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The influence of the spatial frequency content of discrete roughness distributions on the development of the crossflow instability
... eigenmode, transition can be controlled and even delayed 26,27,28 ...the transition location 29,30 ...the transition location 30 ...the transition process than the frontal area or volume of ...
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Effects of Forward-Facing Step Shape on Stationary Crossflow Instability Growth and Breakdown
... height, transition moved upstream relative to the no-step ...since transition did not move upstream. However, the stationary crossflow amplitudes near the step were significantly impacted, though ...
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Crossflow Transition At Mach 6 On A Cone At Low Angles Of Attack
... the Crossflow Cone by designer Chris Ward [51], was used for the first two tunnel entries, to study the crossflow instability on a 7 ◦ half-angle cone at low angles of ...The Crossflow Cone is ...
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Experimental and theoretical study of swept-wing boundary-layer instabilities: Unsteady crossflow instability
... cross-flow instability were devoted basically to stationary disturbances—the so-called cross-flow vortices (see, ...the transition process initiated by the CF instability in various prac- tically ...
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Secondary Instability of Stationary Crossflow Vortices in Mach 6 Boundary Layer Over a Circular Cone
... laminar-turbulent transition due to crossflow instability in swept wing boundary layers [58, ...stationary crossflow evolution in the present ...
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Influence of Stationary Crossflow Modulation on Secondary Instability
... Secondary Instability for Case M Case M corresponds to an intermediate value of the modulation amplitude in relation to the two cases previously considered in subsections III-C and III-D ...for transition ...
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Direct Numerical Simulation of Transition Due to Traveling Crossflow Vortices
... and transition prediction in particular. Transition research under NASA’s Aeronautical Sciences Project seeks to develop a validated set of variable fidelity prediction tools with known strengths and ...
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On the controllability of saturating crossflow vortices
... a crossflow generated by a rotating body can be used as a substitute for a swept wing flow in the context of controlling ...convective instability neutral curves for a rotating sphere in an axial ...
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Simulation and control of stationary crossflow vortices
... co-rotating crossflow vortices that are typically aligned with the potential flow producing a large disturbance in the streamwise bound- ary layer ...the crossflow vortices begin to grow the disturbance ...
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Supersonic Crossflow Transition Control in Ground and Flight Tests
... the transition front flow visualization images were captured in both the tunnel and flight ...that crossflow dominated transition is considered to be less sensitive to temperature effects than ...
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Numerical aspects of searching convective/absolute instability transition
... âGêoæðGë\è)é ãíGïºå¡ä'å\ñ'íGæiäì ë\è ãê?õöGå°ìSöYæíGè+æ÷äOöGè+è åLè ígîiãë°òGè ñ'ë°èãïGñ?äoæÂäOöGèêrèE. òGå\êrè ï2[r] ...
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