Vittorio Selmin

Comparison of static and dynamic fluid-structure interaction solutions in the case of a highly flexible modern transport aircraft wing

Abstract This paper describes the computational work performed by five of the fifteen partners in the Brite-Euram project UNSI, for the prediction of static aeroelastic configurations and dynamic flutter response at transonic conditions, using advanced time-domain fluid-structure coupling methods. The aerodynamic models, mechanical models, and coupling strategies implemented in the different solvers are presented. A code to code validation of the fluid-structure coupled solvers has been achieved in the case of the highly flexible MDO wing. The coupled codes have each been used first for the computation of steady state flow and static deformations at different flight conditions. The investigation of flutter has been carried out for off-design, heavy-cruise flight conditions, using time-consistent numerical simulations. Dynamic responses have been recorded and compared for stable and flutter conditions.

Geometry modelling and industrial parameterisation issues

The paper addresses issues related to the development of a geometrical modelling system and its connection with shape parameterisation and computational grid update. In particular, it is thought that the use of parameterisations based on the modification of an existing shape instead to exploit the direct representation of the geometry results in an increase of flexibility and accuracy. Selected examples related to aircraft design illustrate the capability of the system.

Workflow Resiliency for Large-Scale Distributed Applications

Large-scale simulation and optimization are demanding applications that require high-performance computing platforms. Because their economic impact is fundamental to the industry, they also require robust, seamless and effective mechanisms to support dynamic user interactions, as well as fault-tolerance and resiliency on parallel computing platforms. Distributed workflows are considered here as a means to support large-scale dynamic and resilient multiphysics simulation and optimization applications, such as multiphysics aircraft simulation.

Conclusions and lessons learnt

UNSI brought together competence from many fields. Here expertise in flow physics modelling, aerodynamic software development, structural analysis and aeroelasticity came together to study aspects of fluid-structure interaction, using advanced flow solvers. In this unusually wide span of profession, the industrial participants got an inside view of the difficulties and possibilities offered by new aerodynamic tools, while partners involved in detailed physical modelling had an opportunity to see their work related to industrially relevant applications.

Application-oriented synthesis of work

The current main chapter contains 14 contributions which cover all applications treated within the context of UNSI. Emphasis was placed on cross comparison of data in order to support potential scientists in their own work on validation/verification of all these test cases.

The UNSI Project

The European UNSI (Unsteady Viscous Flow in the Context of Fluid-Structure Interaction) project involved 15 European partners in the period from January 1998 to September 2000. It was undertaken as a major industrial research project in the former DGXII, Brite-Euram, Directorate within the fourth European Community Research Framework Programme.

Summary of work carried out in the main tasks of the UNSI project

In the following 8 chapters, a synthesis of task related work is presented which reflects improvements and enhancements of specific scientific topics that have been tackled in the UNSI project.

Technical, partner reports containing method descriptions and concise presentation of important results

In the following 15 chapters, partners provide an overview about methods used and highlight results achieved. For application oriented results, the reader is referred to Chapter IV, while basic approaches and general information concerning the different tasks in UNSI are provided in Chapter III.