Aircraft development programmes generally involve collaboration in engineering between different organisations, in order to develop innovative products efficiently, to involve necessary skills from the supply chain, and to spread risks and costs among the partners. The size and complexity of the programmes, the market demands and the contexts of competition all require the collaboration to be effective and efficient. Advances in information technology provide new capabilities to support collaborative design but a step change is needed to harness and coordinate this support to be effective and efficient. The extended enterprises in which the collaborative engineering activities take place span the partner organisations. Engineers wishing to cooperate are however facing security constraints. For example, technical security measures such as firewalls and proxy servers hamper smooth exchange of engineering data and seamless execution of collaborative workflows. The restrictions assist organisations in protecting their assets and in remaining compliant with legislation and regulations. From a programme technical point of view, effective and efficient collaboration in this world full of security and the resulting connectivity constraints is a major challenge. This paper describes the usefulness, necessity and challenges of collaboration between multi-disciplinary specialists in aerospace engineering. It presents the ‘Brics’ technology that supports the realisation of cross-organisation collaborative workflows. The technology supports aircraft manufacturers and their supply chains in facing the challenges and in performing analyses of innovative aircraft designs collaboratively. This technology has emerged from past research projects, and has been further developed and successfully demonstrated in the Thermal Overall Integrated Conception of Aircraft project, a research and technology development project carried out in the Seventh Framework Programme funded by the European Union. The developed technology is illustrated in the context of a multi-partner analysis and optimisation study, which has been conducted as part of a pylon design that is subject to thermal constraints.

We present experimental and numerical investigations of vapour phase growth in a two-dimensional model porous medium heated laterally. Visualization experiments reveal the existence of a heat pipe effect within the porous medium when a sufficiently high temperature gradient develops along the porous medium. The bubble growth is characterized by a pattern transition between an invasion percolation (IP) pattern in a first phase of the growth and an invasion percolation in a destabilizing gradient (IPDG) at later times. It is shown that this transition corresponds at the pore scale to a transition between an invasion scenario where only one pore is invaded at each step of the invasion and a multiple pore invasion scenario. The IPDG pattern is characterized by the development of a thin vapour finger, which can explain premature vapour breakthroughs. This type of vapour finger cannot be simulated accurately using traditional models based on the continuum approach to porous media.

We study numerically and experimentally the displacement of a liquid by a gas in a two-dimensional model porous medium. In contrast with previous pore network studies on drainage in porous media, the gas pressurization is fully taken into account. The influence of the gas injection rate on the displacement pattern, breakthrough time and the evolution of the pressure in the gas phase due in part to gas compressibility are investigated. A good agreement is found between the simulations and the experiments as regards the invasion patterns. The agreement is also good on the drainage kinetics when the dynamic liquid films are taken into account.