Ice impact testing conducted in ENOVAL

ENOVAL technology scheme showing the Intermediate Case (IMC)

17 September 2014

The ENOVAL project is exploring and developing low pressure system technologies for fuel efficient and silent Ultra High By-Pass Ratio engines. The importance of light weight solutions for components in the by-pass duct is increasing as the engines are growing in relative size with increasing BPR.

In the EU-project VITAL, an IMC component with a fabricated titanium core structure was assembled with light weight composite guide vanes and a composite fan case achieving a 20% weight reduction compared to state of the art at the time.

GKN Aerospace and SWEREA SICOMP have taken the task to further improve the intermediate case beyond state of the art and what was achieved in VITAL. New material structures and design solutions for the guide vanes are investigated in the early phase of ENOVAL to contribute to the target of reducing weight by 15% compared to the reference technology.

There are multiple stringent requirements for the design of fan outlet guide vanes. One example is to prove hail stone impact resistance. Certification rules define impact requirements with hail stones up to a diameter to 50 mm hitting the aircraft, engine and under some conditions also the guide vanes. Early single vane tests have been performed in ENOVAL to characterize the “no damage” limit for a range of lay-ups and material systems. The tests were conducted at an air gun facility at the Luleå University as part of a project-external collaboration under the leadership of SWEREA SICOMP with vanes designed and manufactured by GKN Aerospace.

The test was successful and the damage limit could be detected with some candidate material combinations reaching above the predefined acceptance level.

The VITAL Intermediate CaseThe short film below shows the test set-up, a slow motion view of the impact event and finally a close up sequence from a high speed recording of the moment when the hail stone hits the vane. The mechanical wave from the impact event turns the hail stone opaque (into fragments) in a very short time.

To contact the Project Coordinator or all technical engineers at GKN Aerospace and SWEREA SICOMP, please see here.

 

Please click below to see the video.