Catálogo de publicaciones - libros

A full set of elastic constants was determined/estimated for two sandwich composite skin laminates. Out-of-plane compression and shear specimens were cut from skin laminates bonded together to avoid making thick laminates. The approach gives relatively low scatter for the elastic constants and little influence from the bonds as judged from finite element analysis.

The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of established turbulence models. These issues are:

All models developments and applications are carried out with the fluid mechanics software CFX-5 of ANSYS Inc. (CFX-5, 2004).

In this chapter the main outcomes of the activity made by Alenia in the framework of Flomania project are outlined.

The main technical achievements that have been obtained are: 1. Validation of CFD methods and assessment of their application envelope in cases which present critical features with respect of turbulence modelling. 2. Improvement of the quality of CFD simulation codes including a dvanced RANS turbulence modelling, under the aspects of reliability and robustness. 3. Assessment of the influence of computational grid and of the benefits induced by the use of mesh adaptation techniques.

In addition, the participation to the project work has contributed to individuate directions for the development of company’s CFD codes in the near future, accordingly with the foreseen needs of aerodynamic design.

The contribution of Bombardier Transportation (BT) seeks to scrutinize the prospects of (DES) for the investigation of external aerodynamic flows in an industrial context. The focal point is on inherently transient, massively separated flows at = 10 − 10, which feature a considerable amount of turbulent-transient interaction. Examples investigated refer to calibration and verification exercises, baseline validation and exemplary applications using a commercial software package. Results are compared against companion (unsteady) RANS simulations next to experimental and numerical data taken from literature. Findings convey that DES is able to accurately predict transient phenomena in massively separated turbulent flows. Moreover, the approach clearly outperforms unsteady RANS simulations at comparable computational expenses. Although the DES method is significantly more efficient than LES and yields noticeable potential for industrial CFD, the computational effort of the inherently 3D and unsteady approach is still considerable.

The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of established turbulence models. These issues are:

All models developments and applications are carried out with the fluid mechanics software CFX-5 of ANSYS Inc. (CFX-5, 2004).

Since CFD is crucial for an accurate aerodynamic design of aircraft, Dassault Aviation was involved in many of the major European projects dedicated to the improvements of CFD technologies, such as EUROVAL, ECARP, AVTAC, LESFOIL, UNSI, IDeMAS. The ambitious goals of Flomania, together with the expertise of the partners involved, naturally motivated us to take an active part into the project.

Developments performed within this project aimed at the enhancement of the turbulence models currently used They concern the improvement of wall functions, and the evaluation of two turbulence models: the v-f and an improved version of the k-l. Computations were also performed in order to evaluate the new developed models on an industrial configuration (3D transonic wing and walls of the wind tunnel), and to provide a basis for detailed comparisons between the most advanced two equations models (EARSM) and RSM. In this respect, two test-cases were computed: a 3D transonic wing (M6 wing) and a delta wing at two different angles of attack.

Here we briefly review the two numerical methods used by DLR during the FLOMANIA project as well as some remarks on the turbulence models available in these codes including some remarks on the implementation of DES and RSM. Furthermore some additional results obtained with the latter models are presented which are not mentioned elsewhere in this book.

This chapter summarizes the activities of EADS-CASA in the FLOMANIA Project, providing some highlights about the implementations and results carried out using the in-house EMENS code. Among the computations performed, the MRTT (which is reported separately), the NACA0012 with round tip, the Obi diffuser and the RAE2822 airfoil are reported. The implementations include the SALSA TM and two types of wall functions: the Scalable WF and the Automatic WF. We are grateful to the TUB for their support with the SALSA; and we are also grateful to the INTA, which shares with EADS-CASA the EMENS code, for their collaboration in many aspects of the implementations.

The present chapter summarises effort at EADS-M on validation of turbulence models to bridge the gap between the most advanced research results obtained in recent years in the area of turbulence modelling and their application in daily industrial practice. To cope with the main aspects in flow physics, in particular in turbulence modelling, results and descriptions presented are concerned with reliability, robustness and accurate knowledge of the limitations of currently used eddy viscosity models. In addition, a process has been initiated to both investigating on full DSM models in industrial aerodynamic CFD codes and creating the industrial transition process towards DES and thus the next generation of turbulence modelling.

The numerical method used in EDF’s unstructured finite volume code is described, with an emphasis on boundary conditions. Through close collaboration with FLOMANA partners, UMIST in particular, implementation of SSG, SST, V2F models and scalable wall functions could be finalised. The wing-tip vortex and the 3D hill cases were computed in URANS mode, the latter also with LES using a synthetic turbulence method.