On the Performance of Highly Aggressive Inter Compressor Ducts

Abstract

The improvement of jet engine components can lead to an escape of the understood design space. In particular, the trend towards short and therefore highly aggressive inter compressor ducts (ICD) extends the traditional design space. Potential benefits in terms of fuel savings due to a reduction in engine weight are in contrast to a more complex flow field. Many studies consider the secondary flow system of highly aggressive ICDs at the design point but there is a lack of off-design considerations. To fill this gap, the present study investigates in detail the off-design performance of the new German Aerospace Center (DLR) test case. Firstly, CFD simulations of different typical operating points allow detailed considerations of the flow field under off-design conditions. Secondly, a variation of the inlet conditions describes the sensitivity of highly aggressive ICDs to different low-pressure compressor operating points. Finally, the comparison of the CFD stagnation pressure loss with the loss predicted by a preliminary off-design method validates the use of traditional off-design prediction during the preliminary design of highly aggressive ICDs.