The Clean Sky joint technology initiative, a e1.6 billion ($2.2 billion) private-public partnership on aeronautical research in Europe, has issued its third call for proposals. Working toward the development of a green rotorcraft, the consortium is focusing on engines, aerodynamics and tiltrotors.
The consortium is looking to integrate diesel engines into a light helicopter and is studying the entire helicopter architecture, rather than just engine performance. The applicant it selects for this project will have to analyze the loads the engine generates and study methods for cutting vibration in engine installation.
The selected company will also have to perform a thermodynamic analysis of the engine, in turn leading to studies of engine and engine-bay cooling.
Electric, oil and fuel systems will have to be optimized for the diesel engine. Fadec is also to be included in the architecture study. This project is budgeted at e497,000 ($676,000) over three years.
In the field of aerodynamics, the consortium is looking to reduce drag by improving the fuselage and rotor head. The topic of study is a light helicopter with a blunt aft-body region and landing skids, such as a Eurocopter EC135 or EC145.
The selected applicant will test, in a wind tunnel, new shapes the consortium supplies. It will have to build a model no more than six feet long and with a simplified fuselage. The model should be modular, meaning the mast fairing, the landing skids, the rotor hub and hub cap should be easily replaceable.
The rotor hub must be realistic in terms of shape and adjustable in collective and cyclic pitch. It will not have to be controlled in real time, however, and the hub can be fixed or rotating. Moreover, the model should allow the rotor mast to tilt forward and backward by five degrees.
In addition to the basic configuration, the consortium will provide two sets of landing skids, two rotor heads, one or two mast fairings and possibly spoilers, strakes and vortex generators. The components’ effect on airflow around the aft body would be studied.
This project is budgeted at e827,000 ($1.1 million) over four years.
The consortium also plans to study drag reduction with tiltrotors. Areas of interest are the fuselage/wing junction, the nose, the landing-gear sponsons and the empennage. The European industry has long been working on a tiltrotor concept dubbed Erica.
The selected applicant will have to use computational fluid dynamics to fine-tune these areas. It will still have to avoid or minimize any degradation of lift and moments. It is also asked to create an “optimal design” procedure that could be used in an actual program. This project is budgeted at e898,000 ($1.2 million) over three years. AgustaWestland, which is developing the BA609 with Bell, is not the only European company working on tiltrotors. Eurocopter is keeping an eye on them, too, but has nothing flying as yet.