For short waves (high frequencies) the Fresnel number limits infinitely. For higher wavelengths the Fresnel number limits to zero. The outdoor barrier ...

The Fresnel number (F), named after the physicist Augustin-Jean Fresnel, is a dimensionless number relating to the pattern a beam of light forms on a surface

The advisability of the use of the Fresnel number as the measure (characteristic) of the ratio of diffraction and focusing properties for ultrasonic transducers ...

The Fresnel numbers and sound attenuation at point D are shown in Table 5 and Figure 5. Finally, the noise reduction program is determined. A sound barrier ...

In summary, the Fresnel number is an important measure indicating the ratio of geometrical and diffraction effects on the beam propagation. The Fresnel number ...

The design of an acoustic lens that reduces the diffraction spreading from an ultrasonic, transducer to produce a narrow focused beam is proposed. The design is ...

The advisability of the use of the Fresnel number as the measure (characteristic) of the ratio of diffraction and focusing properties for ultrasonic ...

Thus the Fresnel's number and further the noise level attenuation are different from one frequency to another.

2 дек. 2021 г. · Based on the same source Fresnel number N1, the relation of the sound attenuation of pure tones with a thin rigid barrier is: A b K A = 20 log ...

The results of these experiments indicate that the correct attenuation curve (in decibels vs Fresnel number "N") for a point source is given by Fresnel's ...