This paper provides a concise overview of the aeroengine industry serving the large civil aircraft market together with a discussion of the key market drivers and the strategic issues within this industry. With the airlines feeling increased pressure to improve their market performance and their associated strategies for focusing more on their core businesses, the outsourcing of aeroengine overhaul and maintenance has thus provided the original equipment manufacturers (OEMs) with the opportunity to strategically align with their customers. As the OEMs therefore become service providers, effectively providing thrust for 20 years, the new core competences that must be attained are discussed. They must extend their deep product knowledge in design and manufacture to those of negotiation of the long-term service agreements for their tailored service offerings and in the lifecycle engineering of their products to ensure successful fulfilment of these contracts. In the eyes of their customers the aeroengine OEMs will be seen as risk mitigators and critical to their success will the development and utilisation of knowledge-based tools for the provision of informed decision-making. The future need for such tools and the challenges are identified within this paper so that both the airlines and OEMs can minimise their risks and cost base.

In this paper a new moving-boundary algorithm is presented for the solution of two-dimensional flows on unstructured grids. Application of this algorithm is investigated by simulating the internal ballistics of solid rocket motors (SRM). Solution domain is discretised to a number of triangular elements using control-volume based finite-element (CVFE) method. Euler equations are integrated over the control volumes, and Roe's flux-difference scheme is used to evaluate flux vectors at the control-volume surfaces. To eliminate numerical errors due to grid movement, geometric conservation laws (GCL) are carefully implemented. The present algorithm recognises locations along the moving boundaries where the stretched elements result in a distorted grid. To avoid this, new elements are inserted through a local re-triangulation of elements in these regions. Internal ballistics of three SRMs with cylindrical grains burning from inside, are numerically simulated. Using a heat transfer model, erosive burning is included in calculation of propellant burning rate. The aftend of third SRM is tapered to demonstrate capability of present algorithm in solving problems with moving boundaries approaching each other. Very good agreement is observed between the time variations of head-end chamber pressure, obtained from the present work and the other methods.

A new methodology is described to identify aircraft dynamics and extract the corresponding aerodynamic coefficients. The proposed approach makes use of fuzzy modelling for the identification process where input/output data are first classified by means of the concept of fuzzy clustering and then the linguistic rules are extracted from the fuzzy clusters. The fuzzy rule-based models are in the form of affine Takagi-Sugeno models, that are able to approximate a large class of nonlinear systems. A comparative study is performed with existing techniques based on the employment of neural networks, showing interesting advantages of the proposed methodology both for the physical insight of the identified model and the simplicity to obtain accurate results with fewer parameters to be properly tuned.