PROJECT EFFAN "EFicient FAN"
CleanSky Theme: JTI-CS-2013-1-SGO-02-051
"Fan optimization for aeronautic ECS application"
On an electrical ECS pack, outside air is used to remove heat from the cooled system. The outside air flow is generated on ground thanks to a vacuum device. The present subject deals with electrical fan solution used as vacuum device for ram air flow generation. The challenge of optimizing such a component for this application is double.
First, from aerodynamic point of view, the fan shall be capable to generate pressure drop whatever the flow without surge issues. Indeed, the ram air fan is used to suck main air flow through ECS pack main heat exchanger for cabin cooling and in the meantime to suck small amount of flow through ECS pack electrical motor stator for cooling. Due to ECS control logics, the fan shall be also capable to ensure ECS motor stator cooling without any flow from main heat exchanger. In this case it shall provide the same pressure rise with a very limited flow.
Then, the fan is installed downstream of the ECS main heat exchanger. Therefore, high temperature air can enter the fan and specific concept shall be implemented for fan integration to enable fan mechanical and electrical subpart cooling.
Finally, technology and solution selected to comply with these last constraints shall minimize impact on performance efficiency and component reliability and availability so as to achieve global ECS objectives.
A new fan concept will be selected from available bibliographic and consortium expertise, and designed using the consortium skills in deep fundamental fluid mechanics and heat transfer knowledge (Universitat Politècncia de Catalunya - UPC), advanced CFD tools and aerodynamic know-how (Termo Fluids - TF) and engineering capacities of a fan manufacturer (LMB). The proposed design related to surge problem will be implemented in a prototype and tested accordingly. In a similar manner, a solution for electrical motor cooling will be found.The final solution must also consider its impact on the whole ECS pack, in order to maintain its global performance objectives.