@techreport{oai:jaxa.repo.nii.ac.jp:00044914,
 author = {河内, 啓二 and KAWACHI, Keiji},
 month = {Feb},
 note = {The fundamentals of the Local Momentum Theory (Azuma,A. and Kawachi,K.,“Local Momentum Theory and Its Application to the Rotary Wing”, Journal of Aircraft, Vol.16, No.1, January 1979, pp.6-14) and a recent extension of this theory are presented in this report. The Local Momentum Theory is basd on the instantaneous balance between the fluid momentum and the blade elemental lift at a local station in the rotor rotational plane. Therefore, the theory has the capability of evaluating timewise variations of airloading and induced velocity distributions along a helicopter blade span. Unlike a complex vortex theory, this theory was developed to analyze the instantaneous induced velocity distribution effectively. This presentation of the fundamentals of the Local Momentum Theory makes clear the boundaries of this theory and assists in making a computer program using this theory. A new concept introduced into the theory in this report is the effect of the rotor wake contraction in hovering flight. A comparison of this extend Local Momentum Theory with a prescribed wake vortex theory is also presented. The results indicate that the extended Local Momentum Theory has the capability of achieving a level of accuracy similar to that of the prescribed wake vortex theory over wide range variations of rotor geometrical parameters. It is also shown that the analytical results obtained using either theory are in reasonable agreement with experimental data., 資料番号: NALTR0657000, レポート番号: NAL TR-657},
 title = {The Fundamentals of the Local Momentum Theory and Its Extension to a Distorted Wake Model of a Hovering Rotor},
 year = {1981}
}