A Documentation of Two- And Three-Dimensional Shock-Separated Turbulent Boundary Layers


Book Description

A shock-related separation of a turbulent boundary layer has been studied and documented. The flow was that of an axisymmetric turbulent boundary layer over a 5.02-cm-diam cylinder that was aligned with the wind tunnel axis. The boundary layer was compressed by a 30 deg half-angle conical flare, with the cone axis inclined at an angle alpha to the cylinder axis. Nominal test conditions were P sub tau equals 1.7 atm and M sub infinity equals 2.85. Measurements were confined to the upper-symmetry, phi equals 0 deg, plane. Data are presented for the cases of alpha equal to 0. 5. and 10 deg and include mean surface pressures, streamwise and normal mean velocities, kinematic turbulent stresses and kinetic energies, as well as reverse-flow intermittencies. All data are given in tabular form; pressures, streamwise velocities, turbulent shear stresses, and kinetic energies are also presented graphically. Brown, J. D. and Brown, J. L. and Kussoy, M. I. Ames Research Center SEPARATED FLOW; SHOCK WAVE INTERACTION; SHOCK WAVES; THREE DIMENSIONAL BOUNDARY LAYER; TURBULENT BOUNDARY LAYER; FLOW VELOCITY; GRAPHS (CHARTS); KINEMATICS; KINETIC ENERGY; PRESSURE; SHEAR STRESS; TABLES (DATA)...




Documentation of Two- And Three-Dimensional Hypersonic Shock Wave/Turbulent Boundary Layer Interaction Flows


Book Description

Experimental data for a series of two- and three-dimensional shock wave/turbulent boundary layer interaction flows at Mach 7 are presented. Test bodies, composed of simple geometric shapes, were designed to generate flows with varying degrees of pressure gradient, boundary-layer separation, and turning angle. The data include surface-pressure and heat-transfer distributions as well as limited mean-flow-field surveys in both the undisturbed and the interaction regimes. The data are presented in a convenient form for use in validating existing or future computational models of these generic hypersonic flows. Kussoy, Marvin I. and Horstman, Clifford C. Ames Research Center NCC2-452; RTOP 505-80-11...










Fluctuations and Massive Separation in Three-Dimensional Shock-Wave/Boundary-Layer Interactions


Book Description

Shock-wave unsteadiness was observed in rapidly compressed supersonic turbulent boundary layer flows with significant separation. A Mach 2.85 shock-wave/turbulent boundary layer flow was set up over a series of cylinder-flare bodies in the High Reynolds Number Channel 1. The transition from fully attached to fully separated flow was studied using axisymmetric flares with increasing compression angles. In the second phase, the 30 deg flare was inclined relative to the cylinder axis, so that the effect on a separated flow of increasing 3 dimensionality could be observed. Two 3-D separated cases are examined. A simple conditional sampling technique is applied to the data to group them according to an associated shock position. Mean velocities and turbulent kinetic energies, computed from the conditionally samples data, are compared to those from the unsorted data and to computed values. Three basic questions were addressed: can conditional sampling be used to provide snapshots of the flow; are averaged turbulence quantities dominated by the bimodal nature of the interaction; and is the shock unsteadiness really important to computational accuracy. Kussoy, M. I. and Brown, J. D. and Brown, J. L. and Lockman, W. K. and Horstman, C. C. Ames Research Center NASA-TM-89224, NAS 1.15:89224 NCC2-452...




Shock Wave-Boundary-Layer Interactions


Book Description

Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.




On the Structure of Three-Dimensional Shock-Induced Separated Flow Regions


Book Description

A study is made of existing experimental data on three-dimensional skewed shock-wave interactions with both laminar and turbulent boundary layers and recent results in which extensive regions of turbulent separation were obtained. Comparisons show that the structure of three-dimensional shock-wave/boundary-layer interactions is not fundamentally different for laminar or turbulent flow; it is primarily dependent on the extent of separation. A qualitative description is given for the flow structure from incipient to large extents of separation. For the latter, a secondary incipient condition arises within the primary separation vortex. For still larger extents of separation it is deduced that a secondary vortex arises adjacent to the surface and totally embedded in the primary separation vortex. (Author).