Sentence examples for blade tone from inspiring English sources

In the present set of experiments, the method is extended to include cancellation of the harmonics of the blade tone.

At the design speed with supersonic flow conditions in the rotor blade channels, blade tone noise and buzz-saw noise are the main contributors.

A special case is also examined where the frequency of the blade tone harmonic lies just above the cut-on frequency of the first higher order mode of the fan ducting.

In particular, cancellation of a fan's blade tone fundamental was achieved by replacing a section of the fan's cut-off where the aerodynamic blade tones are generated with two appropriately driven secondary sources.

In this case, the blade passing frequency component is generated mainly by the rotor 2/struts interaction, and the higher blade tone harmonics, which dominate the overall tone noise level, are produced by the interaction of the two rotors.

Results indicate that active control is effective at the harmonics of the blade tones as well as the fundamental for a variety of fan loading conditions and duct terminations.

showed a noise reduction as large as 8·9dB in the blade passing tone.

At 50k and 70kr.p.m., the reduction in blade passing tone was 5·5 and 2·6dB respectively.

In addition, far field radiation of the blade passing frequency tone and overall noise is reduced by an average of 4 dB SPL in the forward sector (0° to 110° from the inlet axis).

As much as 5 dB reduction in the overall sound pressure level and as much as 15 dB reduction in the blade passing frequency tone were observed when the IGV was moved from 0·8 chord of rotor blade upstream of the fan face to 2·0 chord of the blade upstream.

It was found that the extent of the reductions in the blade passing frequency tones in both the inlet and outlet duct varied with the orientation of and the extent of open area on the mouth perforate.