국내 최대 기계 및 로봇 연구정보

공학설계D/B

공학설계D/B 게시판 내용
Volume Title	Vibration and Acoustic Fatigue
Volume No	Loading actions (near-field jet, buzz-saw noise due to fan, turbulent boundary layer) and Damping (estimation in laminated plates, use of damping treatments).
DATA Title	Prediction of near-field and far-field harmonic noise from subsonic propellers with non-axial inflow.
DATA Item	95029
KEYWORD	discrete, far, field, frequency, harmonic, level, near, noise, pressure, program, propeller, rotational, sound
ISBN	085679 962 9
ABSTRACT	ESDU 95029 introduces a Fortran program for estimating the noise from an isolated single rotating propeller in uniform motion or stationary in a lossless atmosphere without temperature gradients or wind. Thickness noise and noise due to tangential and axial loading are treated. The airflow need not be parallel to the propeller axis. The observer may be stationary or on the aircraft which may be climbing or descending. Noise due to non-linear effects arises at tip relative Mach numbers exceeding 0.9 but is neglected in the program. Input required includes power, thrust, and the radial distributions of chord, thickness/chord ratio, blade angle, coordinates of the mid-chord line, and the steady (and the magnitudes and phases of unsteady) drag and lift coefficients. If unsteady lift and drag coefficient distributions are not available, an option is provided to have the lift distribution calculated within the program using the method of ESDU 96027. The omission of the drag coefficient distribution is thought to have a negligible effect on the noise calculation in comparison with the lift coefficient distribution. There is an option to output results in either reception coordinates (based on the location of the propeller when the noise reaches the observer) or emission coordinates (based on the its location when the noise was emitted). Details of the input and output format are illustrated by a worked example, and the program (ESDUpac A9529) is provided on disc in the software volume both uncompiled and compiled within ESDUview, a user-friendly shell that prompts on-screen for input data.