Simple approach for modeling fan systems with a computational-fluid-dynamics-based body-force model

This paper presents the use of a conventional computational-fluid-dynamics-based throughflow method to model the effects of a bypass fan in a propulsion system (for example, nacelle) under the restriction that information about the fan blade geometry is unavailable. Instead, the fan body-force model requires fan-performance data at different operating points as input. A simple implementation strategy is proposed to achieve this goal and extend the use of the body-force model to off-design operating conditions where fan-performance data are limited. This approach has been validated with axisymmetric calculations on three blade rows to demonstrate its capability at off-design conditions. The toolmaybe very useful to nacelle designers,whooften have limited information about fan-performance data from engine suppliers. Acknowledgments This work was partially funded by The Boeing Company through a collaboration with Colorado State University under subaward G- 00255-1. The authors are grateful for the contributions of Hin-Fan Lau and Sho Sato at The Boeing Company, as well as Xinfeng Gao at Colorado State University. We also thank Nathan Spotts for providing some of the computational-fluid-dynamics results.