AIR ENGINE DESIGN Russian patent published in 2009 - IPC F02C7/32 

FIELD: engine engineering, aviation.

SUBSTANCE: in accordance with the present invention fillet fairing is installed inside bypass channel of the external engine circuit in order to avoid outer thickness of auxiliary mechanisms and gear boxes and to actuate them. The external circuit channel is between engine housing and inner circuit of compressor/engine turbine. The fillet fairing dimensions are enough to accommodate auxiliary mechanisms. At the same time the external circuit channel is correspondingly made axisymmentrical to avoid or compensate any blocking effect from fillet fairing within the channel limits when air flows. In addition the fillet fairing may be provided for placing engine oil tank as well as filter/heat exchanger mechanisms foreseen for engine. Under the above circumstances it is essential that elongated cylindrical engine profile is maintained so that reduced cross section is required allowing for the engine to keep a reduced glider of air craft. As a result acoustic shock waves profile is improved.

EFFECT: elimination of outer thickness when auxiliary mechanisms are placed.