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geometries, large structures with high permeable media and sandwich panels with core inserts, the flow behaves
in a very complex manner. Flow simulation allows the prediction of the flow front advancement, the total
filling time and the exerted forces within the cavity during impregnation. The evolution of the curing system can
be predicted as well, so different curing cycles can be tested virtually before bringing them into production.
This tool is able to support engineers during design of the manufacture process in order to avoid critical heat
concentration regions during exothermal curing, especially in the case of thick walled parts.
Productive process simulation is based on effective modelling and accurate material models. In this presentation
a method for characterising the permeability of reinforcements with high permeable layer is explained, and
how it can be applied in flow simulation for the design of complex structures is presented as well. An approach
for the management of cure temperatures by means of curing simulation is proposed for the optimisation of the
curing phase of thick components.
Title: Coupled Eulerian-Lagrangian analysis to predict impact damage to
fluid-filled composite structures
Authors: R. A. Gibbon
Frazer-Nash Consultancy Limited
Time: November 4, 2009 5:20 pm
Room: Lumen
Numerical finite element methods are increasingly used to simulate the impact behaviour and subsequent damage
of composite materials.
Within the aerospace industry composites are being specified for a growing number of components to take
advantage of the potential for weight saving that they can offer. However unlike conventional metallic materials,
the complex failure mechanisms of composite structures mean the consequences of an impact event can be
diverse.
A number of aerospace applications of composites result in a fluid-filled composite structure. Damage caused
by an impact event onto these structures is not necessarily limited to the impact site but can also extend to other
areas of the structure as a result of pressure waves in the fluid.
This paper presents the results of an investigation into damage of fluid-filled composite structures using coupled
Eulerian-Lagrangian analysis. The impact is modelled analytically in ABAQUS, and the results compared to
those obtained experimentally.
The work provides an extremely useful insight into how modern numerical simulation methods can be used to
predict damage inflicted upon composite components during impact events encountered during service.
37
SESSION B3B ENGINES
Chair: Prof. H. Funke (FH Aachen)
Title: CFD modeling of combustion and ignition processes in aeroengine
combustion chamber
Authors: Prof. A. Boguslawski, Dr. A. Tyliszczak
Czestochowa University of Technology
Time: November 4, 2009 4:00 pm
Room: Candela
A common view in academic and industrial research centers working on the combustion optimization in
aeroengines is that the real breakthrough in the development of a new design of aeroengine, with significantly
reduced emissions of greenhouse gases, requires advanced modelling of turbulent flow and turbulence/
combustion interaction in combustion chamber. Commonly used in industrial design RANS methods are limited
to steady combustion processes while in the case of non-premixed combustion unsteady large scale structures
are responsible for fuel and oxidizer mixing and as a consequence combustion efficiency. The limitations of the
RANS methodology are well known after the decades of use in industrial applications. Unsteady flame behaviour
and flame stability are especially important in the case of new low emission combustion chambers based
on lean fuel combustion technology. The unsteady and ignition processes are of major importance due to
safety reasons as the altitude relight and light across characteristics are mandatory for a new design of combustion
chamber. A natural choice for efficient modelling of mixing and non-premixed combustion is Large
Eddy Simulation (LES) method according which large scale flow structures controlling mixing of fuel and
oxidizer are resolved directly on the basis of filtered Navier-Stokes equations and small scale structures, much
more isotropic, are modelled with the use of subgrid model. LES approach in industrial applications, much
more feasible for nowadays computers than DNS (Direct Numerical Simulation), still requires very fine meshes,
CPU-time and computer storage capacity so a careful mesh design and quality testing for well validated LES
predictions are required. LES, extensively used for simulations of academic testcases, in industrial design is still
considered as a new tool and particular attention is necessary for validation in the case of complex geometry
　
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