ADVANCED TURBOPROP NOISE PREDICTION BASED ON RECENT THEORETICAL RESULTS

This paper is about the development of a high speed propeller noise prediction code at Langley Research Center. The code utilizes two recent acoustic formulations in the time domain for subsonic and supersonic sources. The selection of appropriate formulation is automatic in the code. The structure and capabilities of the code are discussed. Grid size study for accuracy and speed of execution on a computer is also presented. The code is tested against an earlier Langley code. Considerable increase in accuracy and speed of execution are observed. Some examples of noise prediction of a high speed propeller for which acoustic test data are available are given. A brisk derivation of formulations used is given in Appendix 1.

[1]  F. Farassat,et al.  A numerical technique for calculation of the noise of high-speed propellers with advanced blade geometry , 1980 .

[2]  G. P. Succi,et al.  The prediction of helicopter rotor discrete frequency noise , 1982 .

[3]  D. B. Hanson,et al.  Propagation of propeller tone noise through a fuselage boundary layer , 1984 .

[4]  Christopher K. W. Tam,et al.  Weakly nonlinear acoustic and shock-wave theory of the noise of advanced high-speed turbopropellers , 1986, Journal of Fluid Mechanics.

[5]  F. Farassat.  Theoretical analysis of linearized acoustics and aerodynamics of advanced supersonic propellers , 1985 .

[6]  K. G. Mackall,et al.  Measurement and analysis of acoustic flight test data for two advanced design high speed propeller models , 1984 .

[7]  J. W. Rawls,et al.  Effects of boundary layer refraction and fuselage scattering on fuselage surface noise from advanced turboprop propellers , 1984 .

[8]  U. K. Singh,et al.  Time marching methods for turbomachinery flow calculation , 1979 .

[9]  F. Farassat.  The Evolution of Methods for Noise Prediction of High Speed Rotors and Propellers in the Time Domain , 1986 .

[10]  D. B. Hanson,et al.  The importance of quadrupole sources in prediction of transonic tip speed propeller noise , 1978 .

[11]  R. Kanwal.  Generalized Functions: Theory and Technique , 1998 .

[12]  G. L. McAninch,et al.  A note on propagation through a realistic boundary layer , 1983 .

[13]  F. Farassat.  Linear Acoustic Formulas for Calculation of Rotating Blade Noise , 1981 .

[14]  H. S. Ribner,et al.  Refraction of sound by jet flow or jet temperature , 1965 .