ðə ɹˈoʊl ʌvðə ɹˈoʊɾɚ blˈeɪdz ɪz tʊ ɐksˈɛlɚɹˌeɪt ðɪ ˈɪŋkʌmˌɪŋ ˈɛɹ fɔːɹ ɪŋkɹˈiːsɪŋ ðə kᵻnˈɛɾɪk ˈɛnɚdʒi ʌvðɪ ˈɛɹ.
The role of the rotor blades is to accelerate the incoming air for increasing the kinetic energy of the air.