Device for heating an aerofoil

DETAILED DESCRIPTION The invention thus proposes a device for heating an aerofoil, comprising electrically conducting longitudinal fibers extending substantially parallel to a leading edge of the aerofoil in a region of the aerofoil including said leading edge, and means for electrically connecting the ends of the longitudinal conducting fibers to an electric power supply.
The conducting fibers are grouped together in conducting rovings forming part of a hybrid fabric embedded in cured resin, this hybrid fabric further including a weft of electrically insulating fibers woven together and woven with the conducting rovings.
The insulating fibers of the hybrid fabric provide the conducting fibers with cohesion during the construction and shaping of the device.
They prevent the longitudinal conducting fibers from dispersing, which makes them easier to handle, and allows them to be aligned parallel to the leading edge.
The hybrid fabric can adopt relatively complicated shapes, while at the same time ensuring an even distribution of conducting fibers.
The weft formed by the insulating fibers holds the conducting rovings, to a large extent preventing them from spreading out and from contracting, while at the same time allowing a certain amount of relative slippage between the fibers in order to allow the fabric to follow relatively complicated shapes.
The heating device according to the invention can be adapted for different distributions of surface heating-power density according to need.
One possibility is to provide several layers of hybrid fabric over some portions of the region near the leading edge.
Another possibility is to provide for some portions of the hybrid fabric to have just a fraction of the density of rovings of conducting fibers in the other portions of hybrid fabric.
This may be obtained simply by local removal of conducting rovings from a uniform hybrid fabric.
In an advantageous embodiment, the hybrid fabric further includes rovings of transverse conducting fibers woven with the insulating fibers of said weft and with the rovings of longitudinal conducting fibers