Laminar-Turbulent Transition

The International Union of Theoretical and Applied Mechanics (IUTAM) decided in 1992 to sponsor the fourth Symposium on Laminar-Turbulent Transition, Sendai/Japan, 1994. The objectives of the present Symposium were to deepen the fundamental knowledge of stability and laminar turbulent transition in three-dimensional and compressible flows and to contribute to recent developing technologies in the field. This Symposium followed the three previous IUTAM-Symposia (Stuttgart 1979, Novosibirsk 1984 and Toulouse 1989). The Scientific Committee selected two keynote lectures and 62 technical papers. The Symposium was held on the 5th to 9th of September, 1994, at the Sendai International Center in Sendai. The participants were 82 scientists from 10 countries. The keynote lectures have critically reviewed recent development of researches concerning the laminar-to-turbulent transition phenomena from the fundamental and the application aspects. Many papers presented were concerned about the detailed mechanism of the boundary layer transition (receptivity, secondary instability, turbulent spot and bypass transition). Particular emphasis was further placed on the transition of three-dimensional boundary layers on rotation systems and on swept wings. Attention was also given to compressible hypersonic flows.

Texte du rabat

The origin of turbulent flow and the transition from laminar to turbulent flow are the most important unsolved problems of fluid mechanics and aerodynamics. Besides being a fundamental question of mechanics, there are numerous applications for information regarding transition location and details of the subsequent turbulent flow.This volume contains two review papers and 60 technical papers presented by internationally recognised authorities covering new developments of transition research on three-dimensional and compressible boundary layers, receptivity, crossflow instability, turbulent spot and transition control.

Contenu
Keynote Lectures Chairman : T. Tatsumi.- A Survey of the Transition Prediction Methods: from Analytical Criteria to PSE and DNS.- Some Fundamental Problems on Transition to Wall Turbulence.- Session A : Fundamentals I.- Is the Classic, Weakly Nonlinear Theory of Hydrodynamic Stability Good Enough and How It Can Be Improved.- Role of Non-Wave-Like Disturbances in Transition.- Interaction of Phase-Locked Modes: A New Mechanism for the Rapid Growth of Three-Dimensional Disturbances.- Stability of Two- and Three-Dimensional Time-Dependent Flows with Locally-Uniform Strain Rates.- Session B : Fundamentals II.- The Incompressible Attachment-Line Boundary-Layer Stability.- Secondary Instability Associated with Streamwise Vortices in a Rotating Boundary Layer.- Laminar-Turbulent Transition in Spherical Couette Flow.- Non Linear PSE Compared with DNS and Experiment.- Session C : Fundamentals III.- Fine Structure of the 3-Dimensional Transition Region in the Wake behind a Thin-Shell Cylinder Placed Parallel to a Uniform Flow.- Transition to Turbulence in Pipe Flow.- Subcritical Disturbance Growth Caused by Hairpin Eddies.- Session D : Flow Measurements and Controls.- In-Flight Measurements on a Laminar Wing Glove by Means of Surface Sensor Arrays.- Laminarization of Three-Dimensional Compressible Boundary-Layer Flow Using Receptivity Control.- Relaminarisaton of the Swept Wing Attachment-Line by Surface Suction.- Session E : Compressible Flows.- Nonlocal and Local Instability Analysis of Hypersonic Flows.- An Exploratory Study of Transition on a Slender Cone in Hypervelocity Flow.- Session F : Poster Session I ( Fundamentals, Flow Measurements, Controls, Compressible Flows and Turbulent Spot).- Turbulence in Pulsatile Flow through the Tube with Elastic Wall.- Experimental Study of Boundary Layer Suction Effects on Leading Edge Contamination along the Attachment Line of a Swept Wing.- Nonlinear Development of Waves in the Supersonic Boundary Layer.- Analysis of the Formation of a Turbulent Spot in a Laminar Boundary Layer.- Entropy- and Boundary Layer Instability of Hypersonic Cone Flows - Effects of Mean How Variations -.- Mathematical Nature of Parabolized Stability Equations.- High-Speed Boundary-Layer Stability and Transition.- Vortex Dynamics of a Vortex Ring Introduced into a Laminar Boundary Layer.- Experiments on Secondary Instability of Channel Flow with Body Forces.- Numerical Simulation of Boundary Layer Flow over Suction Holes.- Numerical Simulation on Laminar-Turbulent Transition of the Channel Flow with Simulated Wall Roughness.- Session G : Bypass Transition and Turbulent Spot.- The Development of a Turbulent Spot in an Adverse Pressure Gradient Boundary Layer.- Spatial Simulations of Bypass Transition in Boundary Layers.- The Natural Evolution of Turbulent Spots in a Flat Plate Laminar Boundary Layer.- Turbulent Spot in 3-D Constant Pressure Flow.- Session H : Swept Wings.- Experimental Study of Secondary Instability and Breakdown in a Swept Wing Boundary Layer.- Development of Stationary Crossflow Vortices on a Swept Wing.- Session I: 3-D Boundary Layers I.- An Experiment on Transition of Three-Dimensional Boundary Layer.- Instabilities Developing in the Three-Dimensional Boundary Layer on Concave and Convex Curved Surfaces.- Effects of Wall and Streamline Curvatures on Instability of 3-D Boundary Layers.- Session J : Poster Session II ( Swept Wings, 3-D Boundary Layers, 2-D Boundary Layers and Receptivity ).- Stability of Two-Phase Boundary Layer on a Flat Plate.- On the Receptivity of a Flat Plate Boundary Layer toLocalized Free Stream Disturbances.- Comparison of Asymptotic Prediction Methods for Boundary-Layer Receptivity.- On Excitation of Unstable Boundary Layer Waves by Freestream Sound.- The Resonant-Triad Interaction in Boundary-Layer Transition.- Experimental Study of Cross-Flow Instability of a Swept-Wing Boundary Layer with Respect to Traveling Waves.- Stability Characteristics of 3-D Boundary Layer on a Yawed Cone.- Absolute Instability of the Rotating-Disk Boundary Layer.- Spatial Direct Numerical Simulation of Transition in a Three-Dimensional Boundary Layer.- Numerical and Experimental Investigation of the K-Regime of Boundary-Layer Transition.- Effect of Leading Edge on Sound Receptivity.- On Similarity Law of the Crossflow Instability in Three-Dimensional Boundary Layers on Yawed Cylinders.- Numerical and Experimental Investigation of Secondary Instability in Leading Edge Boundary Layer Flow.- Comparison between the Orr-Sommerfeld and Asymptotic Theories for the Flat-Plate Boundary Layer.- Session K : 3-D Boundary Layers II.- Analysis of the Instability of the Boundary Layer over a Rotating Disk.- Randomization Process in Crossflow Instability Dominant Three-dimensional Boundary-Layer Transitions.- Session L : 2-D Boundary Layers.- Experiments on Nonlinear Interaction between Oblique Tollmien-Schlichting Waves.- Three-Dimensional Instability of the Blasius Boundary Layer.- Direct Numerical Simulation of Boundary-Layer Transition with Strong Adverse Pressure Gradient.- Session M : Receptivity I.- A Partial Simulation of Receptivity and Transition in 3-D Boundary Layers.- Distributed Excitation of Cross-Flow Vortices in Three-Dimensional Boundary Layers.- The Receptivity of Rat-Plate Boundary-Layers with Two-Dimensional Roughness Elements to Freestream Sound and Its Control.- Session N : Receptivity II.- Laminar Boundary-Layer, Sound Receptivity and Control.- On 3-D Boundary Layer Receptivity.