Download or read book In Flight Measurement of Propeller Noise on the Fuselage of an Airplane written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-08 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In-flight measurements of propeller noise on the fuselage of an OV-10A aircraft were obtained using a horizontal and a vertical microphone array. A wide range of flight conditions were tested including changes in angle of attack, sideslip angle, power coefficient, helical tip Mach number and advance ratio, and propeller direction of rotation. Results show a dependence of the level and directivity of the tones on the angle of attack and on the sideslip angle with the propeller direction of rotation, which is similar to results obtained in wind tunnel tests with advanced propeller designs. The level of the tones at each microphone increases with increasing angle of attack for inboard-down propeller rotation and decreases for inboard-up rotation. The level also increases with increasing slideslip angle for both propeller directions of rotation. Increasing the power coefficient results in a slight increase in the level of the tones. A strong shock wave is generated by the propeller blades even at relatively low helical tip Mach numbers resulting in high harmonic levels. As the helical tip Mach number and the advance ratio are increased, the level of the higher harmonics increases much faster than the level of the blade passage frequency. Pla, Frederic G. and Ranaudo, Richard and Woodward, Richard P. Glenn Research Center...

Download or read book In flight Measurement of Propeller Noise on the Fuselage of an Airplane written by and published by . This book was released on 1989 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propeller Noise Measurements in DNW on the Fuselage of a Twin Engine Aircraft Model written by T. Zandbergen and published by . This book was released on 1985 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Study of Noise Reduction for an Unstiffened Cylindrical Model of an Airplane Fuselage written by Conrad M. Willis and published by . This book was released on 1981 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In flight Near and Far field Acoustic Data Measured on the Propfan Test Assessment PTA Testbed and with an Adjacent Aircraft written by Richard P. Woodward and published by . This book was released on 1993 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sources Control and Effects of Noise from Aircraft Propellers and Rotors written by John S. Mixson and published by . This book was released on 1981 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propeller Aircraft Interior Noise Model written by L. D. Pope and published by . This book was released on 1984 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ground Noise Measurements During Landing Take off and Flyby Operations of a Four engine Turbopropeller STOL Airplane written by David A. Hilton and published by . This book was released on 1971 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Noise measurements were obtained for a four-engine turbopropeller STOL airplane during a Federal Aviation Administration flight evaluation program at the National Aviation Facilities Experimental Center. These noise measurements involved landing-approach, takeoff-climbout, and flyby operations of the airplane. A total of 13 measuring positions were used to define the noise characteristics around a simulated STOL port. The results are presented in the form of both physical and subjective measurements. An appendix is included to present tabulated values of various subjective reaction units which may be significant for the planning and operation of STOL ports. The main source of noise produced by this vehicle was found to be the propeller, and noise levels decrease generally in accordance with the inverse-distance law for distances up to about 457 meters. For similar slant ranges, somewhat lower noise levels were experienced during flyby than during takeoff or landing.

Download or read book Consideration of Some Factors Affecting Low frequency Fuselage Noise Transmission for Propeller Aircraft written by John S. Mixson and published by . This book was released on 1986 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Noise reduction Measurements on Stiffened and Unstiffened Cylindrical Models of an Airplane Fuselage written by Conrad M. Willis and published by . This book was released on 1984 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Noise Propagation from a Four engine Propeller driven Airplane written by William L. Willshire and published by . This book was released on 1987 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeroacoustics of Flight Vehicles Noise control written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Correction Procedures for Aircraft Noise Data Volume V Propeller Aircraft Noise written by David Brown and published by . This book was released on 1980 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report examines three particular problem areas associated with the measurement of noise levels of propeller-driven small airplanes required to comply with FAR Part 36, Appendix F. These problems are directly related to effects of atmospheric conditions on (1) the performance capabilities of an airplane when tested at various barometric pressures and altitude densities; (2) the noise signature generated at such conditions; and (3) the propagation of sound from the airplane to the measuring station. The first two of these have been addressed by deriving potential correction procedures which could be applied to noise levels obtained by tests not in strict compliance with Appendix F. These corrections are based on aircraft operations conducted within a specific margin of power setting. The corresponding measured noise levels are subsequently corrected for variation of propeller tip speed, forward velocity and barometric pressure relative to predetermined reference conditions. The third effect, that of sound propagation, si examined by applying SAE ARP 866A to a typical propeller airplane noise spectrum and demonstrating the range of A-weight noise levels that would result within a range of ambient conditions. (Author).

Download or read book Uniform Practices for the Measurement of Aircraft Noise written by Aircraft Industries Association of America and published by . This book was released on 1952 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sound Pressures and Correlations of Noise on the Fuselage of a Jet Aircraft in Flight written by Russell D. Shattuck and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Preliminary Comparison Between the SR 6 Propeller Noise in Flight and in a Wind Tunnel written by and published by . This book was released on 1983 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: