Annual Report Department

3.3Thermal and fluid engineering

3.3.1FWO project: Large Eddy Simulations G.0130.02: Large Eddy Simulation for multiphase flows and complex physics flows with emphasis on combustion applications

Partners: VUB, Dienst Stromingsmechanica, K.U.Leuven – TME

Objective: In a previous FWO project a professional RANS code was extended for LES applications. Hereby emphasis was put on  accurate and efficient numerical techniques for LES as well as appropriate modelling of the subgrid-scales. At present LES techniques are further refined and extended for flows where RANS models are less appropriate, in casu multiphase gas-particle/droplet flows and flows with turbulence-chemistry interactions. An important application field, common to both flow types, is combustion. The applications envisaged are no premixed combustion in a single phase and spray combustion. The research focuses on i) refinement of LES models and schemes for use in complex flows; ii) extension of LES for no premixed combustion applications; iii) extension of LES for multiphase gas-particle/droplet flows and spray combustion; iv) PIV and hot-wire experiments to support the numerical developments.

Period: Jan 2002 – Dec 2005

Contact: M. Baelmans

3.3.2HOBU-project: Balanced and controlled ventilation systems for healthy living conditions in houses, apartments and colleges with a minimal energy consumption

Partners: De Nayer Hogeschool, Sint-Katelijne-Waver, K.U.Leuven - TME

Objective: This project is coordinated by the De Nayer Hogeschool in Sint Katelijne-Waver. The project aims at the development of a decision methodology to achieve optimally designed ventilation systems in different types of buildings and this at a minimal energy consumption. Therefore different ventilation systems are experimentally investigated and characterised in a dedicated test rig. Subsequently, their operating conditions in real systems are monitored and simulation methods for the design of ventilation systems are evaluated.

Period: Oct 2002 – Sep 2004

Contact: M. Baelmans

3.3.3IWT-project with Pauwels Trafo Belgium N.V: Modelling and investigation of new cool­ing techniques for power transformers

Partners : Pauwels Trafo Belgium N.V., K.U.Leuven - TME

Objective: In this project new cooling techniques such as directed oil cooling for oil-filled power transformers are investigated. To this end the in-house thermal design tool is extended and validated against experiments. Ex­periments are conducted both on a test rig and on full-scale transformers.

Period: Dec 2000 – Feb 2003

Contact: M. Baelmans

3.3.4IWT SBO Powermems

Partners : K.U.Leuven - PMA, K.U.Leuven - TME, K.U.Leuven - Electa, K.U.Leuven - Micas, Imec, VKI, KMS

Objective: The objective of the project is the design of a micro gas turbine for portable electrical power generation. More particularly a micro heat exchanger for a Brayton gas turbine cycle with recuperation will be developed. Also the problem of thermal insulation of the different gas turbine components will be studied.

Period: Nov 2003 - Oct 2007

Contact: D. Reynaerts, M. Baelmans, F. Verplaetsen

3.4Manufacturing processes

3.4.1BRITE EURAM Project no. GRD1-200-25135 AUTOFETT Affordable Flexible System for Off-line Automated Fettling and Finishing

Partners: The Casting Technology International (UK), LIPS B.V. (NL), Norton Cast Products Ltd. (UK), Cometna (P), Kranendonk (NL), ABB Flexible Automation (S), CRF (I), KPS Rinas (D), K.U.Leuven (B)

Objective: The AUTOFETT project aims to develop and demonstrate a complete manufacturing system for carrying out a combination of automated fettling and finishing operations on medium/heavy section castings in a production environment. The manufacturing system will be based on a robot for foundry applications. This research project includes the following tasks: development of intelligent end-effectors(e.g. force controlled), development of new methods for the off-line (and collision free) programming of the robot, the development of process models to support the off-line programming and the design and construction of equipment(including sensing systems) for the efficient control of the process on the one hand and the easy handling and precise location of castings on the other hand.

Period: Feb 2001 – Jan 2004

Contact: B. Lauwers

URL: http://www.mech.kuleuven.ac.be/pma/project/autofett

3.4.2EU growth project no. G1RD-CT-2002-00774 "EDM2005": A new concept for the economic Wire-EDM of high quality carbide tools

Partners: PMA KULeuven (B), Plansee Tizit (A), Charmilles Technologies (CH), Oel-Held (D), Bekaert (B), Corrada (I), FCI (B)

Objective: The EDM2005 project aims at the high quality and reliable wire electrical-discharge machining of complex carbide punches and dies with small radii and tight tolerances within a competitive time in comparison with conventional machining methods, leading to increased tool life (of the punches) and decreased production cost. This means above all a better surface and sub-surface integrity. The project also aims the development of a test procedure for evaluating the quality of punches. Standardisation efforts will be undertaken to propose the developed test procedure as a common standard.

Period: Jun 2002 – May 2005

Contact: B. Lauwers

3.4.3FWO Project no. G.0216.00: Selective laser sintering of products in metal-ceramic materials

Partners: K.U.Leuven-PMA, K.U.Leuven-MTM

Objective: The project aims to further develop the technology of Selective Laser Sintering (SLS) of powders (mainly metals, MMCs, cermets and ceramics). It involves research and development with respect to the process (process parameters, etc.), the SLS machine (powder deposition, laser technology, etc.) and the materials (study of material behaviour, development of new powders and powder combinations, etc.).

Period: Jan 2000 – Dec 2003

Contact: J.-P. Kruth, B. Lauwers

3.4.4GBOU-project no. 010071, SPARK : Electrically conductive wear resistant composite materials

Partners: PMA KULeuven (B), Department MTM (Metallurgy and applied material science) KULeuven (B), Vakgroep Mechanische Constructie en Productie UGent (B)

Objective: The project has two objectives. First of all it wants to investigate the machineability by wire-EDM of a number of commercial ceramic composites, including hard metals. It is necessary to evaluate the state of the art thoroughly and critically, because there is a shortage of published data. This study has three sub-objectives.

Selection of electrically conductive commercial composites. Investigation of the machineability of these materials by wire-EDM. Testing the wear for examining the possible applications of these materials. The second objective of this project is to gain more knowledge about the correlation between the microstructure of the composites and their machineability and wear resistance. Using these results new materials will be developed that have both good machineability and wear resistance. More info on the on-going project can be found at the project's homepage.

Period: Jan 2001 – Dec 2005

Contact: J.-P. Kruth, B. Lauwers

3.4.5GOA project no. GOA/2002/06 : Analysis and exploitation of the interaction between materials and processes for a better machinability of metallic materials and cermets in thermo-physical manufacturing

Partners: K.U.Leuven-PMA, K.U.Leuven-MTM

Objective: The project aims to investigate the interaction between thermo-physical manufacturing processes and the material being processed. in those processes. The processes being studied are two electro discharge machining processes (i.e. wire-cutting-EDM and milling-EDM) and two laser beam machining (laser beam cutting and selective laser sintering).

The project starts with a fundamental experimental study of the interaction phenomena occurring in those processes. In a second phase, it will try to apply the acquired knowledge and insight to modify both the processes and the materials used, in order to achieve better machinability for materials already machined with those processes and to make it possible to machine other advanced materials, non yet commonly used with those processes. The project focusses on metallic materials and cermets (ceramic-metal composites).

Period: Oct 2001 – Dec 2006

Contact: J.P. Kruth, B. Lauwers, J. Duflou

3.4.6IAP-P/08 Project (OSTC): From microstructure towards plastic behaviour of single- and multiphase materials

Partners: K.U.Leuven-MTM (network-coordinator), UCL, TU Eindhoven, U.Liège, VUB-Brussels, K.U.Leuven-PMA, Royal Military Academy, Univ. Groningen, CNRS/Université Paris 13.

Objective: The aim of the project is to develop constitutive models to reflect the influence of various generic aspects of the microstructure on the plastic deformation of single- or multiphase materials. The long-term objective is to improve the understanding of materials behaviour in order to be able to design better advanced materials, and to design better products made from them. The modelling work will be inspired and validated by experimental work. PMA is mainly involved in the experimental investigation and validation of the behaviour of new high strength multiphase materials (STRIP, TWIP and IF steels, Aluminum) under plastic deformation in complex multi-axial loading conditions, combining tensile, compression, bending and shear, as it occurs in sheet metal bending.

Period: Jan 2002 – Dec 2006

Contact: J.P. Kruth, J. Duflou

3.4.7IWT-project Bekaert ‘Steel Reinforced Thermoplastics (SRTP)/ Steel Reinforced Thermoplastic Sheets’

Partners: N.V. Bekaert S.A. (B), EPFL-LTC (CH), K.U.Leuven (MTM/PMA)(B)

Objective: The project studies the feasibility of steel reinforcements in thermoplastics and is divided into 5 main tasks: literature search, interfacial control, processing of laminates, transformation into product and characterisation of mechanical properties. A general literature search focuses on the potential advantages of steel composites and on potential market applications. A scientific literature search provides the background for the research: bonding technologies, adhesion, impregnation and draping of meshed materials. The aim of the second task is to develop coupling agents or methodologies to provide an adequate bonding between the polymer and the steel wires. Modelling tools for the impregnation of a thermoplastic polymer into preforms of steel wires are provided in the processing task. PMA is involved in the 4^th task to determine the parameters of the stamping process for shaping the steel-reinforced sheets. The processing of the material will be optimised by the definition of a ‘process drapability/deformability window’. This window relates the principal transformation parameters (strain, strain rate, temperature,…) to the final part quality, in terms of matrix-reinforcement adhesion, void content and surface quality. It also takes into account the economic constraints on the process: cycle time and equipment cost. This process window will serve as an engineering tool for the design process. In the last task, specific features of thermoplastic composites are discussed.

Period: Jan 2001 – Jan 2004

Contact: D. Vandepitte, M. Lossie, L. Bogaerts

3.4.8IWT 020573 "ThermHex: A fundamental knowledge base for the production and use of thermoplastic folded honeycomb cores"

Partners: K.U.Leuven, Department MTM, Johnson Controls Gent, Libeltex, Polyvision, Toyota Motor Europe, DaimlerChrysler (Germany), Kaysersberg Packaging (France), Polynorm (the Netherlands), Rieter Automotive (France)

Objective: This project targets in the research on the folded honeycomb material ThermHex. ThermHex is a new concept for the production of honeycomb core materials, developed and patented by the K.U. Leuven. This thermoplastic honeycomb core is produced from a single continuous thermoplastic sheet by a series of successive in-line operations. The technical and economical feasibility of the concept was already proven in the IWT/EUREKA project FoldHex, but further elaboration of the concept is necessary. In this IWT project, a series of reliable production steps will be developed, via the realisation of a lab-scale production line. Furthermore, the material choice, the mechanical properties and the thermoforming behaviour of ThermHex honeycomb core sandwich panels will be investigated. This research will create a knowledge base for future production and use of this thermoplastic folded honeycomb core material and for the technologies related to it.

Period: Apr 2002 - May 2004

Scientific staff: D. Vandepitte, P. Bratfisch

3.4.9Bilateral industrial project with Charmilles Technologies: "Research on Electro-Discharge Machining"

Partners: K.U.Leuven - PMA, Charmilles Technologies S.A. (Switserland)

Objective: K.U.Leuven – PMA and Charmilles Technologies located in Geneva, Switserland, are having bilateral coöperation since 1975. Through the years many aspects of Electro-Discharge Machining (EDM) have been investigated, and this has given rise to several patents and PhDs. The focus of research in 2003 lies on EDM-milling (PhD of Dr. Ph. Bleys), EDM surface alloying, EDM machining of cemented carbides and ceramics, development of special wires for wire-cutting EDM (coated steel wires).

Period: Jan 2003 – Dec 2005

Contact: J.P. Kruth, B. Lauwers

3.4.10IWT project no.030518 Lightback "Development of a lightweight backing panel material with a TorHex honeycomb core and polyurethane resins for automotive interior applications"

Partners: RECTICEL nv (Wetteren, B), K.U.Leuven - MTM, K.U.Leuven - PMA

Objective: The objective of this project is the development of a lightweight sandwich panel to be used as a substrate for car interior panels. The panel is based on a TorHex paper sandwich core and fibre reinforced polyurethane skins. The formability of the sandwich construction has to be investigated to be able to produce complex shaped threedimensional components. The components should be ultra light weight, and they should have the required mechanical properties. Next to the effect of material selection on mechanical properties, the process for forming complex threedimensional sandwich panels will also be developed. The development will be verified with the prototype of a car door interior panel.

Period: Jun 2003 – May 2005

Contact: D. Vandepitte

3.4.11IWT Project no. 030413: “MonAlac: Monitoring for adaptive laser cutting”

Partners: KUL - PMA, LVD Company N.V., Xenics N.V.

Objective: Laser cutting is a complex process that is influenced by many parameters (laser power, cutting speed, focus distance, gas pressure,…). The intention is to develop a control system that supports real time adaptive control of the proces parameters in function of the observed quality. In order to realize this, in a first stage a sensor system will be developed with which the cut quality will be monitored. Since the workpiece quality is not directly measurable in-process, suitable parameters will need to be identified that correlate well with the quality and that are measurable in production. Different types of sensors (acoustic, photodiode, etc.) will be considered. In a second, follow-up phase a control system will be developed that will adapt the proces parameters based on the obtained information. The final envisaged result is a measuring and control system that will make an autonomous production of workpieces with guaranteed quality possible.

Period: Oct 2003 – Sep 2005

Contact: J. Duflou, J.-P. Kruth

3.4.12IWT Project no. 30262: 'Sheet Metal Oriented Prototyping and Rapid Manufacturing SEMPER’

Partners: KUL - PMA, VUB - MEMC, Ulg – M&S, KUL – MTM

Objective: The SEMPER project will create an experimental platform for the exploration of a number of newly emerging techniques for sheet metal forming and complementary trimming processes. Objective is to identify the most promising flexible forming techniques and to develop them to a level that brings manufacturing of sheet metal parts with an industrially acceptable precision within reach.

Keywords in this respect are fast and flexible since the ultimate goal is to provide the building blocks for the development of a new generation of sheet metal oriented prototyping systems.

Period: Oct 2003 – Sep 2007

Contact: J. Duflou, B. Lauwers

3.4.13TAP/PAT Project no. PA-01-321 (OSTC - Belgian Federal Science Policy Office): "Rapid prototyping and manufacturing for space components"

Partners: K.U.Leuven - PMA, CRIF-WTCM Materials division, Centre Spacial de Liège

Objective: The general purpose of the project is to bring together the know- how available in Belgium on rapid prototyping/rapid manufacturing and to apply it to the space sector and to develop those technologies to the specific needs of the space sector. The technical objective is to borrow generic technologies from the domain of 'rapid prototyping', 'rapid product development', and 'rapid manufacturing', and to apply, adapt and further develop those technologies to make them appicable to the development and fabrication of prototypes and components for the spatial sector. Basides the technical objective, the project aims to be a major stimulus to establish a network of organisations and industries that will hare their needs, research results and solutions in the above mentioned domains. During the first year the focus of the activities at K.U.Leuven went to the identification of the requirements of aerospace industry, to the development of a high precision stereolithography process using a liquid curtain recoating system, to the selective laser sintering (SLS) of space materials (Ti, nylon and steel), to the construction of lightweight hollow structures (by SLS), and to the construction of some specific space parts that were tested at CSL (a/o degassing test).

Period: Jan 2003 – Dec 2005

Contact: J.P. Kruth