[ad_1]
The US military has prioritized developing a quieter helicopter design that will allow it to use these vehicles for surveillance and cargo transportation without the noise of traditional helicopters. The military has focused on eVTOL technology as its potential solution, which means future army helicopters could resemble drones.
Helicopters are vertical take-off and landing vehicles (VTOLs), which means that they lift into the air and descend again in the same way. This design is also used for consumer and many commercial drones, although there is one very big and obvious difference: the rotors.
While helicopters have a very large rotor which produces a loud noise, drones have multiple small rotors which reduce the noise level. The US military is studying this type of design for future helicopters, ones that may have a VTOL electric platform with multiple smaller rotors.
The result, the military notes in its press release, will likely be a different sound than we are used to hearing from helicopters. A study was used to confirm that eVTOL will produce a different noise, noting that stacked rotors can reduce noise and increase performance over traditional rotors with blades along a single plane.
Army research engineer Dr. George Jacobellis explained:
I think a stacked rotor can be useful for eVTOL applications. The additional degree of freedom for the design will allow for gains in efficiency and control over the acoustic signature, which has been demonstrated in the results. However, further investigation is needed to quantify the noise reduction with axial spacing.
Source link
