Results 91 to 100 of about 1,929,704 (249)

Acoustic and aerodynamic performance of a 1.83-meter (6-ft) diameter 1.25-pressure-ratio fan (QF-8) [PDF]

A 1.25-pressure-ratio 1.83-meter (6-ft) tip diameter experimental fan stage with characteristics suitable for engine application on STOL aircraft was tested for acoustic and aerodynamic performance.
Lucas, J. G., Woodward, R. P.
core   +1 more source

Acoustic testing of a 1.5 pressure ratio, low tip speed fan (QEP fan B scale model) [PDF]

A scale model (0.484 scale factor) of a single stage fan designed for a 1.5 pressure ratio and 1160 ft/sec tip speed was tested to determine its noise characteristics.
Kazin, S. B., Minzner, W. R., Paas, J. E.   +2 more
core   +1 more source

Rotor performance characteristics from an aeroacoustic helicopter wind-tunnel test program [PDF]

An investigation of helicopter rotor noise at model scale was conducted in the Langley 4 by 7 meter tunnel. The program described was the first of a planned three-phase project whose purpose was to examine the characteristic noise mechanism involved in ...
Elliott, J. W., Hoad, D. R., Orie, N. M.
core   +1 more source

Numerical Investigation of Aerodynamic Noise Reduction of Nonpneumatic Tire Using Nonsmooth Riblet Surface. [PDF]

Appl Bionics Biomech, 2020
Zhou H, Jiang Z, Yang J, Zhai H, Wang G.
europepmc   +1 more source

A shock wave approach to the noise of supersonic propellers [PDF]

To model propeller noise expected for a turboprop aircraft, the pressure ratio across the shock at the propeller tip was calculated and compared with noise data from three propellers.
Dittmar, J. H., Rice, E. J.
core   +1 more source

Prediction of low frequency and impulsive sound radiation from horizontal axis wind turbines [PDF]

, 1981
Theoretical models to predict the radiation of low frequency and impulsive sound from horizontal axis wind turbines due to three sources: (1) steady blade loads; (2) unsteady blade loads due to operation in a ground shear; (3) unsteady loads felt by the ...
Harris, W. L., Martinez, R., Widnall, S. E.   +2 more
core   +1 more source

Effects of Hub Geometry on the Aerodynamic and Acoustic Performance of Axial Flow Fans

Applied Sciences
Axial flow fans are widely used in high-speed train cooling and ventilation systems, where both static efficiency and noise reduction are critical performance requirements.
Weihao Zhang, Renkui Tang, Yang Yu, Yonghua Li   +3 more
doaj   +1 more source

Small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts. Volume 1. Aerodynamic test results [PDF]

The results and analyses of aerodynamic and acoustic studies conducted on the small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts are presented. Various types of nozzle flap concepts were tested.
Nishida, R. S., Renselaer, D. J., Wilkin, C. A.   +2 more
core   +1 more source

Status of advanced turboprop technology [PDF]

, 1978
Research is reviewed in the following areas: turboprop powered transport aircraft; wind tunnel aerodynamic and acoustics tests of model propellers; turboprop maintenance; and wind tunnel tests on airframe-turboprop interactions.
Dugan, J. F., Miller, B. A., Sagerser, D. A.   +2 more
core   +1 more source

Aerodynamic noise from rigid trailing edges with finite porous extensions

, 2017
This paper investigates the effects of finite flat porous extensions to semi-infinite impermeable flat plates in an attempt to control trailing-edge noise through bio-inspired adaptations.
Ayton, L. J., Kisil, A. V.
core   +1 more source