3 results about "Bragg resonance" patented technology

The application discloses a high-sensitivity high-temperature high-pressure sensor based on a high-birefringence grating, which comprises a microstructure optical fiber, the microstructure optical fiber comprises a fiber core and a cladding layer, the fiber core is located at the center of the cladding layer, the microstructure optical fiber has a first polarization direction and a second polarization direction on a radial plane, the first polarization direction is perpendicular to the second polarization direction, symmetrical air hole channels are arranged in the cladding layer on both sides of the fiber core along the first polarization direction, and the air hole channels are parallel to the fiber core; and a high-birefringence grating is formed in the fiber core or the cladding layer of the microstructure optical fiber through periodic refractive index modulation. The high-sensitivity high-temperature high-pressure sensor can directly form two separated Bragg resonance peaks, does not need to use any polarization device for demodulation, and can simultaneously measure temperature and pressure, has high sensitivity to pressure, and can work in a high-temperature environment.

A method, device and equipment for calculating hydrodynamic characteristics of a flexible Bragg submerged dike based on frequency band control and a computer storage medium relate to the technical field of coast and ocean engineering, and the method comprises the following steps: constructing a flexible structure-water wave complete coupling mathematical model; the structural natural vibration frequency and the Bragg resonance frequency of the flexible Bragg submerged dike are calculated to determine a core wave absorption frequency band, and frequency band control conditions of the flexible Bragg submerged dike are formed; weighting the transmission coefficient, the energy loss and the wave load on the basis of a frequency band control condition in combination with a target sea condition spectrum to form a comprehensive evaluation factor, and representing the comprehensive wave dissipation performance and the structural stress performance of the submerged dike; according to the scheme provided by the invention, the hydrodynamic characteristics of the flexible Bragg submerged embankment can be accurately calculated, a scientific basis is provided for reasonable design and arrangement of the flexible Bragg submerged embankment in ocean engineering, and the wave dissipation performance and comprehensive benefits of the submerged embankment are improved.

This invention provides a Bragg resonance breakwater design method and breakwater. The Bragg resonance breakwater design method includes acquiring wave field characteristic parameters of the target sea area and determining the target wave frequency band based on the wave field characteristic parameters; determining the target wave frequency of each resonant unit based on the target wave frequency band, and determining the geometric parameters of the resonant cavity of the resonant unit based on the target wave frequency, so that the inherent resonant frequency of the resonant cavity matches the target wave frequency; determining the reflection coefficient index to characterize the wave dissipation effect based on the target wave frequency band, and determining the arrangement parameters of each resonant unit based on the reflection coefficient index under the premise of satisfying preset constraints, wherein the arrangement parameters change stepwise along the incident wave propagation direction; and outputting the resonant cavity geometric parameters and arrangement parameters corresponding to each resonant unit to form a Bragg resonance breakwater design scheme.