Cernium and Snecma | Date: 2010-10-01
A rotor of a turbomachine compressor, including a bladed rotor disk fitted at its radially external end with a wall forming the inner end of an annual flow channel of a primary gas flow, and formed from multiple angular sectors, each of which is delimited between two blades of the disk which are consecutive in a circumferential direction and includes a bulging portion which is convex in the axial direction and in the circumferential direction, together with, upstream from the bulging portion, a troughed portion which is concave in the axial direction and in the circumferential direction and which has a base which is roughly punctiform.
Agency: Cordis | Branch: H2020 | Program: RIA | Phase: MG-1.1-2014 | Award Amount: 3.05M | Year: 2015
The ability to simulate aerodynamic flows using CFD methods has progressed rapidly over the last decades and has given rise to a change in design processes in aeronautics already. But more improvement is necessary to overcome the (still) existing lack in confidence in CFD usage, based on turbulence modelling. The TILDA project will offer methods and approaches combining advanced and efficient high-order numerical schemes (HOMs) with innovative approaches for LES and DNS in order to resolve all relevant flow features on tens of thousands of processors in order to get close to a full LES/DNS solution for 1billion degrees-of-freedom (DOF) not exceeding turn-around times of a few days. The TILDA project will provide both an improved physical knowledge and more accurate predictions of non-linear, unsteady flows near borders of the flight envelope - which will directly contribute to an enhanced reliability. The main highly innovative objectives, targeting at industrial needs read: Advance methods to accelerate HOM for unsteady turbulence simulations on unstructured grids. Advance methods to accelerate LES and future DNS methodology by multilevel, adaptive, fractal and similar approaches on unstructured grids. Use existent large scale HPC networks to enable industrial applications of LES/DNS close(r) to daily practice. Compact high-order methods offer a very high ratio between computational work per DOF combined to a low data dependency stencil, making these methods extremely well adapted for shared-memory parallel processors, and allow for efficient redistribution over an increased number of processors. Provide grid generation methods for HOM on unstructured grids with emphasis on valid curvilinear meshes for complex geometries, and accounting for mesh and solution quality. Provide suitable I/O and interactive co- and post-processing tools for large datasets. Demonstration of multi-disciplinary capabilities of HOM for LES in the area of aero-acoustics.
Journal of Composite Materials | Year: 2011
As a deviation from the linear fracture criterion for mixed-mode delamination, the original Benzeggagh-Kenane (B-K) fracture criterion with a single parameter can be derived via the assumption on a common mixed-mode resistance to delamination. Through the extension to the framework of separate mixed-mode fracture toughness, a more consistent fracture criterion with two parameters is obtained. Moreover, a theoretical extension to a 3D fracture criterion is also possible. The quality of the modified fracture criterion in the description of fracture locus is investigated by numerical validations against experimental data and comparisons with other fracture criteria. © The Author(s), 2010. Source
International Journal for Numerical Methods in Engineering | Year: 2012
The use of the extended finite element method in the scope of linear elastic fracture mechanics induces the integration of singular functions in terms of the stiffness matrix and in the computation of stress intensity factors using the interaction integral method. An adapted method is proposed in this paper to treat efficiently the three-dimensional case. The improvement is demonstrated by comparison with standard and other methods found in the literature. © 2012 John Wiley & Sons, Ltd. Source
International Journal of Solids and Structures | Year: 2010
Through a mixed local and nonlocal formulation, a continuous transition from a local to a nonlocal behavior is obtained. Initially driven by the local action, the damage driving quantity at a material point in non-damaged materials is later influenced by the nonlocal effect only if the occurrence of damage is effectively found in the surroundings. Qualitative resemblance is hence expected in the prediction of damage initiation by the non-regularized and regularized damage models. Numerical simulations with simple tests and comparisons with existing nonlocal damage models show the qualitative improvement of the mixed formulation in the prediction of damage initiation for 1D and 2D damaged structures. © 2010 Elsevier Ltd. All rights reserved. Source