OPTIMIZING THE ARCHITECTURE OF CIVIL TURBOFAN ENGINES TO IMPROVE LIFE CYCLE COSTS/VALUE ADDED

摘要

In this paper, an economic calculation model is described, which evaluates the "life cycle value added" of an aircraft and an aircraft engine from the end customers' - the airlines'- perspective. The model uses both revenue as well as total costs over the entire product life cycle. It can be used to assess the economic benefit of a certain product (e.g., aircraft or engine), of a defined improvement measure or of different design options. Based on a complex set of parameters, the model can even be used in early design phases, where the potential impact on life cycle cost is the highest. The model is used to show that existing turbofan engines can be improved to deliver extra value for the end customer and as such for the entire value chain. Specific fuel consumption, manufacturing costs, maintenance costs, weight, drag and development costs are the most significant engine parameters for influencing the life cycle value added. An existing modern two-spool high bypass ratio engine was selected as the baseline configuration for applying the model. An analysis of the engine's architecture identified the engine's booster as a potential area of improvement. Upgrading the high-pressure compressor to the latest technology would enable the overall pressure ratio to be maintained while omitting the booster and improving engine performance. The results of the calculation show an improvement of life cycle value added, despite significant one-off development, testing and certification costs. The results support the hypothesis that today's turbofan engines provide room for life cycle costs/value added improvement.