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Relevant bibliographies by topics / Inviscid shear flow

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Academic literature on the topic 'Inviscid shear flow'

Author: Grafiati

Published: 4 June 2021

Last updated: 15 February 2022

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Journal articles on the topic "Inviscid shear flow"

1

Stern, Melvin E. "Blocking an inviscid shear flow." Journal of Fluid Mechanics 227 (June 1991): 449–72. http://dx.doi.org/10.1017/s0022112091000198.

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The upstream influence in an inviscid two-dimensional shear flow around a semicircular ‘cape’ (radius A) is computed using a piecewise uniform vorticity model of a boundary-layer current. The area of this layer upstream from the cape increases as the square root of time t when A is small, and increases as t for larger A. Complete blocking occurs when A is approximately three times the boundary-layer thickness, in which case all oncoming particles accumulate in a large upstream vortex. The numerical results obtained from the contour dynamical method also show the generation of large eddies downstream from the obstacle.

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2

Renardy, Michael. "Short Wave Stability for Inviscid Shear Flow." SIAM Journal on Applied Mathematics 69, no. 3 (January 2008): 763–68. http://dx.doi.org/10.1137/080720905.

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Murad, Abdullah. "Inviscid Uniform Shear Flow past a Smooth Concave Body." International Journal of Engineering Mathematics 2014 (July 23, 2014): 1–7. http://dx.doi.org/10.1155/2014/426593.

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Uniform shear flow of an incompressible inviscid fluid past a two-dimensional smooth concave body is studied; a stream function for resulting flow is obtained. Results for the same flow past a circular cylinder or a circular arc or a kidney-shaped body are presented as special cases of the main result. Also, a stream function for resulting flow around the same body is presented for an oncoming flow which is the combination of a uniform stream and a uniform shear flow. Possible fields of applications of this study include water flows past river islands, the shapes of which deviate from circular or elliptical shape and have a concave region, or past circular arc-shaped river islands and air flows past concave or circular arc-shaped obstacles near the ground.

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4

Balsa, T. F. "On the spatial instability of piecewise linear free shear layers." Journal of Fluid Mechanics 174 (January 1987): 553–63. http://dx.doi.org/10.1017/s0022112087000247.

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The main goal of this paper is to clarify the spatial instability of a piecewise linear free shear flow. We do this by obtaining numerical solutions to the Orr–Sommerfeld equation at high Reynolds numbers. The velocity profile chosen is very much like a piecewise linear one, with the exception that the corners have been rounded so that the entire profile is infinitely differentiable. We find that the (viscous) spatial instability of this modified profile is virtually identical to the inviscid spatial instability of the piecewise linear profile and agrees qualitatively with the inviscid results for the tanh profile when the shear layers are convectively unstable. The unphysical features, previously identified for the piecewise linear velocity profile, arise only when the flow is absolutely unstable. In a nutshell, we see nothing wrong with the inviscid spatial instability of piecewise linear shear flows.

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5

SUGIOKA, KEN-ICHI, and SATORU KOMORI. "Drag and lift forces acting on a spherical gas bubble in homogeneous shear liquid flow." Journal of Fluid Mechanics 629 (June 15, 2009): 173–93. http://dx.doi.org/10.1017/s002211200900651x.

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Drag and lift forces acting on a spherical gas bubble in a homogeneous linear shear flow were numerically investigated by means of a three-dimensional direct numerical simulation (DNS) based on a marker and cell (MAC) method. The effects of fluid shear rate and particle Reynolds number on drag and lift forces acting on a spherical gas bubble were compared with those on a spherical inviscid bubble. The results show that the drag force acting on a spherical air bubble in a linear shear flow increases with fluid shear rate of ambient flow. The behaviour of the lift force on a spherical air bubble is quite similar to that on a spherical inviscid bubble, but the effects of fluid shear rate on the lift force acting on an air bubble in the linear shear flow become bigger than that acting on an inviscid bubble in the particle Reynolds number region of 1≤Rep≤300. The lift coefficient on a spherical gas bubble approaches the lift coefficient on a spherical water droplet in the linear shear air-flow with increase in the internal gas viscosity.

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Zangeneh, M. "Inverse Design of Centrifugal Compressor Vaned Diffusers in Inlet Shear Flows." Journal of Turbomachinery 118, no. 2 (April 1, 1996): 385–93. http://dx.doi.org/10.1115/1.2836653.

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A three-dimensional inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modeled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and nonuniform inlet flow diffusers is found to be most significant from 50 percent chord to the trailing edge region. The flows through both diffusers are computed by using Denton’s three-dimensional inviscid Euler solver and Dawes’ three-dimensional Navier–Stokes solver under sheared in-flow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.

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7

Rizzi, Arthur, and Charles J. Purcell. "Simulation of inviscid vortex-stretched turbulent shear-layer flow." AIAA Journal 24, no. 4 (April 1986): 680–82. http://dx.doi.org/10.2514/3.9326.

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8

MILES, JOHN. "Stability of inviscid shear flow over a flexible boundary." Journal of Fluid Mechanics 434 (May 10, 2001): 371–78. http://dx.doi.org/10.1017/s0022112001003664.

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The stability of an inviscid flow that comprises a thin shear layer and a uniform outer flow over a flexible boundary is investigated. It is shown that the flow is temporally unstable for all wavenumbers. This instability is either Kelvin–Helmholtz-like or induced by the phase shift across the critical layer. The threshold of absolute instability is determined in the form F = F∗(1 + Cεn) for ε [Lt ] 1, where F (a Froude number) and ε are, respectively, dimensionless measures of the flow speed and the shear-layer thickness, F∗ is the limiting value of F for a uniform flow, C < 0 and n = 1 in the absence (as for a broken-line velocity profile) of a phase shift across the critical layer, and C > 0 and n = 2/3 in the presence of such a phase shift. Explicit results are determined for an elastic plate (and, in an Appendix, for a membrane) with a broken-line, parabolic, or Blasius boundary-layer profile. The predicted threshold for the broken-line profile agrees with Lingwood & Peake's (1999) result for ε [Lt ] 1, but that for the Blasius profile contradicts their conclusion that the threshold for ε ↓ 0 is a ‘singular and unattainable limit’.

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9

Arratia, C., and J. M. Chomaz. "On the longitudinal optimal perturbations to inviscid plane shear flow: formal solution and asymptotic approximation." Journal of Fluid Mechanics 737 (November 26, 2013): 387–411. http://dx.doi.org/10.1017/jfm.2013.570.

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AbstractWe study the longitudinal linear optimal perturbations (which maximize the energy gain up to a prescribed time $T$) to inviscid parallel shear flow, which present unbounded energy growth due to the lift-up mechanism. Using the phase invariance with respect to time, we show that for an arbitrary base flow profile and optimization time, the computation of the optimal longitudinal perturbation reduces to the resolution of a single one-dimensional eigenvalue problem valid for all times. The optimal perturbation and its amplification are then derived from the lowest eigenvalue and its associated eigenfunction, while the remainder of the infinite set of eigenfunctions provides an orthogonal base for decomposing the evolution of arbitrary perturbations. With this new formulation we obtain, asymptotically for large spanwise wavenumber ${k}_{z} , $ a prediction of the optimal gain and the localization of inviscid optimal perturbations for the two main classes of parallel flows: free shear flow with an inflectional velocity profile, and wall-bounded flow with maximum shear at the wall. We show that the inviscid optimal perturbations are localized around the point of maximum shear in a region with a width scaling like ${ k}_{z}^{- 1/ 2} $ for free shear flow, and like ${ k}_{z}^{- 2/ 3} $ for wall-bounded shear flows. This new derivation uses the stationarity of the base flow to transform the optimization of initial conditions in phase space into the optimization of a temporal phase along each trajectory, and an optimization among all trajectories labelled by their intersection with a codimension-1 subspace. The optimization of the time phase directly imposes that the initial and final energy growth rates of the optimal perturbation should be equal. This result requires only time invariance of the base flow, and is therefore valid for any linear optimal perturbation problem with stationary base flow.

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10

Meroney, R. N. "Inviscid Shear Flow Analysis of Corner Eddies Ahead of a Channel Flow Contraction." Journal of Fluids Engineering 107, no. 2 (June 1, 1985): 212–17. http://dx.doi.org/10.1115/1.3242464.

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The steady rotational flow of an inviscid fluid in a two-dimensional channel toward a sink or a contraction is treated. The velocity distribution at upstream infinity is approximated by a linear combination of uniform flow, linear shear flow, and a cosine curve. The combinations were adjusted to simulate flows ranging from laminar to turbulent. Vorticity is assumed conserved on streamlines. The resulting linear equations of motion are solved exactly. The solution show the dependence of the corner eddy separation and reattachment on flow geometry and approach flow vorticity and velocity distribution typified by a shape factor.

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Dissertations / Theses on the topic "Inviscid shear flow"

1

Panupintu, Wantana. "The propagation of nonlinear water waves over variable depth with shear flow." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246653.

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Cafolla, Gerard James. "Hydroelastic instabilities of compliant panels." Thesis, University of Warwick, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323370.

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Reboul, Pierre Jean. "Evolution of an infintesimal three-dimensional disturbance in an inviscid parallel shear flow near a wall." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/47317.

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4

Kaffel, Ahmed. "On the stability of plane viscoelastic shear flows in the limit of infinite Weissenberg and Reynolds numbers." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/77325.

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Elastic effects on the hydrodynamic instability of inviscid parallel shear flows are investigated through a linear stability analysis. We focus on the upper convected Maxwell model in the limit of infinite Weissenberg and Reynolds numbers. Specifically, we study the effects of elasticity on the instability of a few classes of simple parallel flows, specifically plane Poiseuille and Couette flows, the hyperbolic-tangent shear layer and the Bickley jet. The equation for stability is derived and solved numerically using the Chebyshev collocation spectral method. This algorithm is computationally efficient and accurate in reproducing the eigenvalues. We consider flows bounded by walls as well as flows bounded by free surfaces. In the inviscid, nonelastic case all the flows we study are unstable for free surfaces. In the case of wall bounded flow, there are instabilities in the shear layer and Bickley jet flows. In all cases, the effect of elasticity is to reduce and ultimately suppress the inviscid instability. The numerical solutions are compared with the analysis of the long wave limit and excellent agreement is shown between the analytical and the numerical solutions. We found flows which are long wave stable, but nevertheless unstable to wave numbers in a certain finite range. While elasticity is ultimately stabilizing, this effect is not monotone; there are instances where a small amount of elasticity actually destabilizes the flow. The linear stability in the short wave limit of shear flows bounded by two parallel free surfaces is investigated. Unlike the plane Couette flow which has no short wave instability, we show that plane Poiseuille flow has two unstable eigenmodes localized near the free surfaces which can be combined into an even and an odd eigenfunctions. The derivation of the asymptotics of these modes shows that our numerical eigenvalues are in agreement with the analytic formula and that the difference between the two eigenvalues tends to zero exponentially with the wavenumber.
Ph. D.

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5

Zillinger, Christian [Verfasser]. "Linear Inviscid Damping for Monotone Shear Flows, Boundary Effects and Sharp Sobolev Regularity / Christian Zillinger." Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/1077290055/34.

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6

Ghosh, Ashis Kumar. "Robust Least Squares Kinetic Upwind Method For Inviscid Compressible Flows." Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1570.

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Books on the topic "Inviscid shear flow"

1

Blackaby, Nicholas D. Inviscid vortex motions in weakly three-dimensional boundary layers and their relation with instabilities in stratified shear flows. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1992.

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2

Blackaby, Nicholas D. Inviscid vortex motions in weakly three-dimensional boundary layers and their relation with instabilities in stratified shear flows. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1992.

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3

Papageorgiou, D. T. The stability of two-dimensional wakes and shear-layers at high Mach numbers. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1990.

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4

United States. National Aeronautics and Space Administration., ed. Vorticity dynamics of inviscid shear layers. [Washington, DC]: National Aeronautics and Space Administration, 1991.

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5

1957-, Jackson Thomas L., Lasseigne D. Glenn, and Institute for Computer Applications in Science and Engineering., eds. Towards enhancing and delaying disturbances in free shear flows. Hampton, Va: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1994.

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6

The nonlinear evolution of inviscid Gortler vortices in three-dimensional boundary layers. Hampton, Va: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1995.

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7

United States. National Aeronautics and Space Administration., ed. Wave number selection for incompressible parallel jet flows periodic in space. [Washington, DC: National Aeronautics and Space Administration, 1997.

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8

Wave number selection for incompressible parallel jet flows periodic in space. [Washington, DC: National Aeronautics and Space Administration, 1997.

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9

Institute for Computer Applications in Science and Engineering., ed. The stability of two-dimensional wakes and shear-layers at high Mach numbers. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1990.

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10

Institute for Computer Applications in Science and Engineering., ed. The stability of two-dimensional wakes and shear-layers at high Mach numbers. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1990.

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Book chapters on the topic "Inviscid shear flow"

1

Rizzi, Arthur, Charles J. Purcell, and J. Thomas McMurray. "Numerical Experiment with Inviscid Vortex-Stretched Flow around a Cranked Delta Wing: Transonic Speed." In Turbulent Shear-Layer/Shock-Wave Interactions, 283–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82770-9_23.

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2

Schmid, Peter J., and Dan S. Henningson. "Linear Inviscid Analysis." In Stability and Transition in Shear Flows, 15–53. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4613-0185-1_2.

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Conference papers on the topic "Inviscid shear flow"

1

LANDAHL, M., and D. HENNINGSON. "The effects of drag reduction measures on boundary layer turbulence structure - Implications of an inviscid model." In Shear Flow Control Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1985. http://dx.doi.org/10.2514/6.1985-560.

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2

Gao, Zhi, Yiqing Shen, and Gecheng Zha. "Viscous/inviscid Interacting Shear Flow Theory with Inferences and Their Applications to CFD." In 52nd Aerospace Sciences Meeting. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2014. http://dx.doi.org/10.2514/6.2014-1445.

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3

Zangeneh, M. "Inverse Design of Centrifugal Compressor Vaned Diffusers in Inlet Shear Flows." In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/94-gt-144.

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A 3D inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modelled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and non-uniform inlet flow diffusers is found to be most significant from 50% chord to the trailing edge region. The flow through both diffusers are computed by using Denton’s 3D inviscid Euler solver and Dawes’ 3D Navier-Stokes solver under sheared inflow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.

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4

Natarajan, Hareshram, and Gustaaf B. Jacobs. "Study of Linear and Non-Linear Instabilities in a Multiple Jet Flow Configuration." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70457.

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The linear and non-linear growth of instabilities in a two dimensional parallel three jet flow configuration is carried out using DNS. A method is presented that enables the study of growth of instability modes using a combination of LSA and DNS. The linear growth of spatial and temporal LSA modes for a single shear layer is verified using DNS. Then DNS is used to study the transition from linear growth to non-linear instabilities. In test, the growth rate of temporal modes found using DNS matches with growth rate predicted by LSA for viscous and inviscid flows. DNS of a non-parallel flow with a spatially growing viscous LSA mode is found to create absolute instability and match between DNS and LSA is not possible. In a temporal analysis, it is found for a multiple shear layer case it is found that the growth of the temporal mode increases with increasing the strength of the additional shear layer for both inviscid and viscous flows. Longer DNS runs show that presence of a stronger shear layer enhances vortex shedding and vortex pairing mechanism of a shear layer. This enhanced mixing in the non-linear region is to be linked with the growth of perturbation in the linear region.

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5

Veyrat, A., J. F. Carrotte, A. D. Walker, C. Hall, and H. Simpson. "A Rapid Viscous-Inviscid Interaction Method for the Preliminary Design of S-Shaped Transition Ducts." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-59515.

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Abstract For preliminary design of compressor transition ducts, knowledge-based tools for the rapid assessment of aerodynamic performance of S-shaped ducts are not currently available in the open literature. This is due to the highly complex flow developing under the combined influence of pressure gradients and streamline curvature. This paper presents a new approach enabling an agile design process avoiding premature use of time-consuming high-fidelity CFD calculations. The features of a 2D axisymmetric incompressible steady flow field are captured with a semi-analytical viscous inviscid interaction method. A potential core, based on streamline curvature and implicit velocity profile by parametric spline reconstruction, is coupled to an integral method predicting the turbulent boundary layer growth up to separation. The shear stress distribution is generated by a modified mixing length model for strongly curved flows and wall shear stress closure is performed by inverse calculation of a composite law-of-the-wall. When compared to CFD, the aerodynamic loading is generally predicted to within ±3% but convergence is achieved 20 times faster.

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6

Radomsky, R. W., and K. A. Thole. "Flowfield Measurements for a Highly Turbulent Flow in a Stator Vane Passage." In ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/99-gt-253.

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Turbine vanes experience high convective surface heat transfer as a consequence of the turbulent flow exiting the combustor. Before improvements to vane heat transfer predictions through boundary layer calculations can be made, we need to understand how the turbulent flow in the inviscid region of the passage reacts as it passes between two adjacent turbine vanes. In this study, a scaled-up turbine vane geometry was used in a low-speed wind tunnel simulation. The test section included a central airfoil with two adjacent vanes. To generate the 20% turbulence levels at the entrance to the cascade, which simulates levels exiting the combustor, an active grid was used. Three-component laser Doppler velocimeter measurements of the mean and fluctuating quantities were measured in a plane at the vane mid-span. Coincident velocity measurements were made to quantify Reynolds shear stress and correlation coefficients. The energy spectra and length scales were also measured to give a complete set of inlet boundary conditions that can be used for numerical simulations. The results show that the turbulent kinetic energy throughout the inviscid region remained relatively high. The surface heat transfer measurements indicated high augmentation near the leading edge as well as the pressure side of the vane as a result of the elevated turbulence levels.

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7

Leoutsakos, G., and K. D. Papailiou. "Transition Prediction in Attached and Separated Shear Layers Using an Integral Method." In ASME 1992 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1992. http://dx.doi.org/10.1115/92-gt-281.

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Calculation of the aerodynamic parameters of axial turbomachinery blades, and an accurate assessment of the flow over the blade surfaces under today’s increasingly demanding requirements for higher efficiencies and optimized blade shapes, at both design and off-design conditions, impose a need for accurate prediction methods able to compute through two sensitive but highly critical phenomena: separation and transition. The present study describes work done on the modelling and prediction of transitional regions, such as those appearing on turbomachinery blading, covering both attached and separated flows. The concept of an engineering method, cheap to run and avoiding complex CFD and turbulence model formulations was always kept in mind. Results include comparisons of integral quantities and velocity profiles in zero, favourable or adverse pressure gradient attached flows, and velocity distributions including points of separation, transition and reattachment in separated airfoil flows, obtained either from a straightforward shear layer calculation or from a viscous-inviscid interaction procedure.

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Moyle, I. N., G. J. Walker, and R. P. Shreeve. "Stator Averaged, Rotor Blade-to-Blade Near Wall Flow in a Multistage Axial Compressor With Tip Clearance Variation." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-030.

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This paper describes the effect of tip clearance changes on the pressure at the case wall of a second stage rotor. Wall shear distributions under the rotor tip are also presented. The results show low pressure areas extending along the rotor suction side but lying away from the blade. Pressure contours indicate the tangential loading at the tip is lower than predicted by two dimensional calculations, however, the predicted loading is observed between the lowest pressure’s path in the passage and the blade pressure side. The results suggest a viscous or shearing layer, due to blade-to-wall relative motion, is generated on the blade side of the tip gap which modifies the inviscid relative flow field and produces an unloading on the blade tip.

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9

Vedantam, Nanda Kishore, and Ramkumar N. Parthasarathy. "Effects of Mean Flow Profiles on the Instability of a Low-Density Gas Jet Injected Into a High-Density Gas." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56794.

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The effects of the mean velocity profiles on the instability characteristics in the near-injector region of axisymmetric low-density gas jets injected vertically upwards into a high-density gas medium were investigated using linear inviscid stability analysis. The flow was assumed to be isothermal and locally parallel. Three velocity profiles, signifying different changes in the mean velocity in the shear layer, were used in the analysis. The effects of the inhomogeneous shear layer and the Froude number (signifying the effects of gravity) on the instability for each set of mean profiles were delineated. At a large Froude number (negligible gravity), a critical density ratio was found for the three profiles at which the jet became absolutely unstable. The critical density ratio for each velocity profile was increased as the Froude number was reduced. A critical Froude number was found for the three sets of profiles, below which the jet was absolutely unstable for all the density ratios less than unity, which demarcated the jet flow into the momentum-driven regime and the buoyancy-driven regime.

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10

Manoharan, Kiran, and Santosh Hemchandra. "Absolute/Convective Instability Transition in a Backward Facing Step Combustor: Fundamental Mechanism and Influence of Density Gradient." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-26435.

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Hydrodynamic instabilities of the flow field in lean premixed gas turbine combustors can generate velocity perturbations that wrinkle and distort the flame sheet over length scales that are smaller than the flame length. The resultant heat release oscillations can then potentially result in combustion instability. Thus, it is essential to understand the hydrodynamic instability characteristics of the combustor flow field in order to understand its overall influence on combustion instability characteristics. To this end, this paper elucidates the role of fluctuating vorticity production from a linear hydrodynamic stability analysis as the key mechanism promoting absolute/convective instability transitions in shear layers occurring in the flow behind a backward facing step. These results are obtained within the framework of an inviscid, incompressible, local temporal and spatio-temporal stability analysis. Vorticity fluctuations in this limit result from interaction between two competing mechanisms — (1) production from interaction between velocity perturbations and the base flow vorticity gradient and (2) baroclinic torque in the presence of base flow density gradients. This interaction has a significant effect on hydrodynamic instability characteristics when the base flow density and velocity gradients are co-located. Regions in the space of parameters characterizing the base flow velocity profile, i.e. shear layer thickness and ratio of forward to reverse flow velocity, corresponding to convective and absolute instability are identified. The implications of the present results on prior observations of flow instability in other flows such as heated jets and bluff-body stabilized flames is discussed.

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