Innovative Propulsors and Engine Integration

Important results from the project

The purpose of the project is to develop propulsors for aircraft engines with reduced fuel consumption and noise. The goal is to develop transonic propellers and compact fan installations and show the improvement potential through analysis and experiments. The double bladed Boxprop has been developed to TRL 3 through optimization at cruise speed and low speed measurements of performance and noise in two wind tunnels. The project has developed a parametric design for axisymmetric isolated and aircraft integrated boundary layer ingesting engine installation to TRL 1-2.

Expected long term effects

The results indicate that a Boxprop gives a transonic efficiency, which is on the level of a conventional, strongly swept propeller, but with a lower tonal noise. Boundary layer ingestion with a turboelectrically driven fan has been shown to reduce the fuel consumption for an airliner by up to 2.5%. The work has generated four masters and one doctoral degree. Geometries, methods and competence from the project has enabled participation in five international and one Swedish project and is the starting point for the ITAP project in NFFP7.

Approach and implementation

The project has developed a spline based method for generally swept, arc shaped propellers. A surrogate model based optimization with automatically generated structured wake following grids is the bases for the design of the Boxprop. Mechanical analysis of anisotropic carbon fibre blades have been developed. A rig for single and counter rotating propellers with a power of 10 kW has been built and used to test propellers up to 26000 rpm. “Class Shape Transformation” has been applied to nacelle geometries and a hybrid drag model has been extended to account for boundary layer ingestion.