TY - JOUR
T1 - Comparison of computational aeroacoustic prediction methods for transonic rotor noise
AU - Brentner, Kenneth S.
AU - Lyrintzis, Anastasios S.
AU - Koutsavdis, Evangelos K.
PY - 1997
Y1 - 1997
N2 - This paper compares two methods for predicting transonic rotor noise for helicopters in hover and forward flight. Both methods rely on a computational fluid dynamics (CFD) solution as input to predict the acoustic near and far fields. For this work, the same full-potential rotor code has been used to compute the CFD solution for both acoustic methods. The first method employs the acoustic analogy as embodied in the Ffowcs Williams - Hawkings equation, including the quadrupole term. The second method uses a rotating Kirchhoff formulation. Computed results from both methods are compared with one another and with experimental data for both hover and advancing rotor cases. The results are quite good for all cases tested. The Kirchhoff method was somewhat sensitive to the location of Kirchhoff surface, if the surface was positioned too close to the rotor blade. The acoustic analogy method was not as sensitive to the extent of volume included in the quadrupole calculation. The computational requirements of both methods are comparable; in both cases these requirements are much less than the requirements for the CFD solution.
AB - This paper compares two methods for predicting transonic rotor noise for helicopters in hover and forward flight. Both methods rely on a computational fluid dynamics (CFD) solution as input to predict the acoustic near and far fields. For this work, the same full-potential rotor code has been used to compute the CFD solution for both acoustic methods. The first method employs the acoustic analogy as embodied in the Ffowcs Williams - Hawkings equation, including the quadrupole term. The second method uses a rotating Kirchhoff formulation. Computed results from both methods are compared with one another and with experimental data for both hover and advancing rotor cases. The results are quite good for all cases tested. The Kirchhoff method was somewhat sensitive to the location of Kirchhoff surface, if the surface was positioned too close to the rotor blade. The acoustic analogy method was not as sensitive to the extent of volume included in the quadrupole calculation. The computational requirements of both methods are comparable; in both cases these requirements are much less than the requirements for the CFD solution.
UR - http://www.scopus.com/inward/record.url?scp=0031189055&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031189055&partnerID=8YFLogxK
U2 - 10.2514/2.2205
DO - 10.2514/2.2205
M3 - Review article
AN - SCOPUS:0031189055
SN - 0021-8669
VL - 34
SP - 531
EP - 538
JO - Journal of Aircraft
JF - Journal of Aircraft
IS - 4
ER -