Hover-capable aircraft

摘要

A hover-capable aircraft having propulsion means; at least one rotor; transmission means for transmitting power from the propulsion means to the rotor and lubricated with a lubricant; a heat exchanger, which receives the heated lubricant from the transmission means and feeds the cooled lubricant back to the transmission means; and a fan for producing airflow through the heat exchanger to cool the lubricant, and which has an impeller with blades, and an exhaust pipe for expelling the hot air produced by cooling the lubricant; at least one portion of the wall of the exhaust pipe has dissipating means designed to selectively absorb pressure waves in a given frequency band related to the rotation speed of the impeller and to the number of blades of the impeller.

主权项

1. A hover-capable aircraft (1) comprising:
propulsion means (6); at least one rotor (3); transmission means (5) for transmitting power from said propulsion means (6) to said rotor (3) and lubricated with a lubricant; a heat exchanger (9), which receives the heated lubricant from said transmission means (5) and feeds the cooled lubricant back to the transmission means (5); and a fan (10) for producing airflow through said heat exchanger (9) to cool said lubricant, and which comprises an impeller (16) with blades (21), and an exhaust pipe (18) for expelling the hot air produced by cooling said lubricant; wherein at least one portion (23) of an outer delimiting wall (22) of said exhaust pipe (18) incorporates dissipating means (25) designed to selectively absorb pressure waves in a given frequency band related to the rotation speed (V) of said impeller (16) and to the number (N) of blades (21) of the impeller (16), wherein said exhaust pipe defines an internal flow path for the hot air with said dissipating means (25) being disposed laterally with respect to said flow path and in a manner in which said dissipating means 25 encircles at least a portion of the flow path.