Whole-field measurements of unsteady separation in a vortex ring/wall interaction

Gendrich, C. P.; Bohl, Douglas; Koochesfahanif, M. M.

doi:10.2514/6.1997-1780

Cited by 14 publications

(10 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the vortex ring approached the porous surface the radius first increased, similar to the increase seen for a vortex ring/wall 8,9 and vortex ring/porous surface 16 …”

Section: B Vortex Screen Interactionsupporting

confidence: 63%

“…The study of vortex rings is well documented and includes: formation, 1-4 transport, [5][6][7] and interaction with solid walls [8][9][10][11] or free surfaces. [12][13][14][15] In most interaction experiments, the vortex ring is allowed to interact with solid or interfacial surfaces.…”

Section: Introductionmentioning

confidence: 99%

“…[12][13][14][15] In most interaction experiments, the vortex ring is allowed to interact with solid or interfacial surfaces. [8][9][10][11][12][13][14][15] These interactions show that for non-permeable surfaces the vortex ring/boundary interaction can produce a range of dynamics depending on the strength of the vortex ring. If a vortex is sufficiently strong, it will form a boundary layer on the surface that separates forming secondary vortex rings that orbit the primary vortex and then convect away from the wall.…”

Section: Introductionmentioning

confidence: 99%

“…The primary vortex may also rebound and begin to convect away from the wall after the interaction occurs. 8,9 For weaker vortex rings, the primary vortex interacts with the wall and stays in proximity to the wall. 9 The development of vortical structures and the interaction of those structures with porous media can be seen in static mixers and filters, flows induced by forest fires, detection of hazardous material residue in clothing, etc.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Flow visualization of a vortex ring interaction with porous surfaces

2012

View full text Add to dashboard Cite

Fluid flow and scalar transport through porous fins Phys. Fluids 26, 055104 (2014); 10.1063/1.4873415 Particle image velocimetry measurements of vortex rings head-on collision with a heated vertical plate Phys. Fluids 22, 053604 (2010);The interaction of vortex rings of constant Reynolds number with porous surfaces composed of wire meshes of constant open area, i.e., surface porosity, but variable wire diameter is studied using flow visualization. The results indicate that several regimes of flow behavior exist in the parameter space investigated. The vortex ring passes through and immediately reforms downstream of the surface for porous surfaces with small wire mesh diameters. The transmitted vortex ring has the same diameter, but lower convection speed and circulation than the pre-interaction vortex ring. For these cases, secondary vortex rings are formed on the upstream side of the porous surface that convect upstream away from the screen. As the wire diameter of the porous surface is increased, smaller sub-scale vortical structures are formed on the transmitted vortex ring as it passes through the surface. The spatial scale of these structures is dependent on the diameter of the mesh wire. The vortex ring is disrupted but is able to reform downstream when these structures are small compared to the scale of the vortex ring. When these structures are large enough the transmitted vortex ring is disrupted and does not reform. The results indicate that the dynamics governing the vortex ring/mesh surface interaction are dependent not only on the strength of the vortex ring and the porosity of the surface, as previously thought, but also on the length scales (i.e., the diameter and spacing of the wire mesh) of the porous surface. C 2012 American Institute of Physics. [http://dx.

show abstract

“…As the vortex ring approached the porous surface the radius first increased, similar to the increase seen for a vortex ring/wall 8,9 and vortex ring/porous surface 16 …”

Section: B Vortex Screen Interactionsupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Flow visualization of a vortex ring interaction with porous surfaces

2012

View full text Add to dashboard Cite

show abstract

“…CFD results showing velocity vectors and projected streamlines at 95% span at (a) design flow coefficient and (b) peak total pressure ratio. Highlighted streamline designates the separation between approach fluid and reverse flow from the tip clearance (Courtesy C. P. Gendrich[17]). instantaneously by the CCD camera.…”

mentioning

confidence: 99%

The Influence of Tip Clearance Momentum Flux on Stall Inception in a High-Speed Axial Compressor

Cameron¹,

Bennington²,

Ross³

et al. 2013

Journal of Turbomachinery

View full text Add to dashboard Cite

Experimental and numerical studies were conducted to investigate tip-leakage flow and its relationship to stall in a transonic axial compressor. The computational fluid dynamics (CFD) results were used to identify the existence of an interface between the approach flow and the tip-leakage flow. The experiments used a surface-streaking visualization method to identify the time-averaged location of this interface as a line of zero axial shear stress at the casing. The axial position of this line, denoted xzs, moved upstream with decreasing flow coefficient in both the experiments and computations. The line was consistently located at the rotor leading edge plane at the stalling flow coefficient, regardless of inflow boundary condition. These results were successfully modeled using a control volume approach that balanced the reverse axial momentum flux of the tip-leakage flow with the momentum flux of the approach fluid. Nonuniform tip clearance measurements demonstrated that movement of the interface upstream of the rotor leading edge plane leads to the generation of short length scale rotating disturbances. Therefore, stall was interpreted as a critical point in the momentum flux balance of the approach flow and the reverse axial momentum flux of the tip-leakage flow.

show abstract