Design of a cone-cylinder-flare configuration for hypersonic boundary-layer stability analyses and measurements with attached and separated flows

International audienceThe stability of hypersonic boundary-layer over axisymmetric cone-cylinder-flare configurations at Mach 6 and zero degree angle of attack is investigated for different Reynolds numbers. The shapes have been specifically designed for wind tunnel test experiments to create well suited geometries for hypersonic laminar-turbulent transition analyses with attached and separated flows taking into account the effects of pressure gradients, flow expansion and recompression, on the hypersonic boundary-layer stability. After a thorough study of the aerodynamic flows obtained in fully laminar conditions on each configuration, linear stability theory (LST) and linear parabolized stability equations (PSE) are used to predict the amplification rates of the boundary-layer disturbances for the case without flow separation. The numerical stability results are compared to wind tunnel measurements obtained in the BAM6QT (Boeing AFOSR Mach-6 Quiet Tunnel) wind tunnel. The semi-empirical eN method allows to correlate transition with the integrated growth of the linear instability waves

Far-Field Drag Extraction fromNumerical Solutions and Wake Surveys

The paper focuses on ONERA drag extraction methods from numerical simulations and flow field wake surveys. A new far-field drag extraction software allows, thanks to the face-based data structure, to extract drag as well from structured (elsA cell-centred) as from unstructured (TAU cell-vertex) RANS solutions

Aircraft drag extraction from patched grid computations

Communication to : 21st AIAA applied aerodynamics conference, Orlando (USA), June 23-26, 2003SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

CFD-Prediction of Maximum-Lift-Effects on Realistic High-Lift-Commercial-Aircraft-Configurations within the European Project EUROLIFT II

Within the framework of the European project EUROLIFT II extensive numerical polar computations for three different stages of gradually increased geometrical complexity of the KH3Y aircraft configuration have been conducted. These challenging computations were performed through the complementary work of five different European institutions. The main objectives of these activities are the assessment of the capabilities of CFD to predict the dependence of the high-lift performance on the Reynolds number and to further improve the understanding of the high-lift associated vortex phenomena, especially the nacelle strake mechanism. The paper will present the key results and the main achievements, as obtained through the challenging research work assigned to Subtask 2.1.3 of the EUROLIFT II project. The focus will be put on the discussion on the aerodynamic phenomena underlined by the comparison of prediction and wind tunnel measurements

Experience sur l'interaction onde de choc couche limite transtionelle dans la soufflerie R2Ch

International audienceTransitional Shockwave/Boundary Layer Interactions (SBLI) is studied experimentally. Experiments are conducted on a hollow-cylinder flare model in the R2Ch blowdown facility at a Mach number of 5 for three different Reynolds numbers in the transitional regime. Unsteady wall pressure measurements are conducted along with mean and unsteady heat flux measurements and high-speed Schlieren imaging. The images are then processed using Proper Orthogonal Decomposition (POD) and Spectral Proper Orthogonal Decomposition (SPOD) to extract relevant information. Two main phenomena are identified and documented: the oblique modes traveling in the shear layer above the recirculation region and the streaks appearing in the reattachment region. New results illustrating the multiple physical origins of the streaks, either linked with globally unstable modes and convectively unstable mechanisms, are discussed