Modelling and design of LPC components with semi-analytical models part I: model formulation and validation

The adoption of very high bypass ratios is an effective strategy to improve the performance of turbofans for civil aviation. Very high-bypass ratio turbofans are characterized by large-diameter fans and large intake diameters, whereas the overall length of the engine and its installation have to be contained to prevent excessive weight growth. As a result, the main components of the low-pressure compression system (LPC) are closer to each other in modern and future engines than they were in less recent designs, if distances are measured in terms of engine diameter. As the axial decay of potential distortions takes place over distances comparable to their tangential wavelength, modern and future engines also display stronger interactions between the intake, the fan, the OGVs and the pylons, causing performance and integrity issues that need to be addressed at the design stage.