In this paper, multipath temporal spreading distributions of laser pulses are calculated when they travel through the seawater. Individual photon is followed in Monte Carlo calculation A modified Henyey-Greenstein （H...In this paper, multipath temporal spreading distributions of laser pulses are calculated when they travel through the seawater. Individual photon is followed in Monte Carlo calculation A modified Henyey-Greenstein （HG） function is applied to represent the scattering phase function of seawater. This paper proposes a new scaling method, which uses the effective scattering thickness τd to replace the optical thickness used in the traditional scaling technique. This paper compares the temporal spreading distributions of photons on conditions of different attenuation coefficients and target depths. The experiments reveal that these mutual deviations are changing in the range from 0.5% to 5%, so long as the corresponding effective scattering thicknesses τd remains the same. Therefore, a conclusion can be obtained, that the temporal spreading distribution is only dependent on the effective diffusion thickness τd .展开更多
In this work,a discrete unified gas kinetic scheme(DUGKS)is developed for radiative transfer in anisotropic scattering media.The method is an extension of a previous one for isotropic radiation problems[1].The present...In this work,a discrete unified gas kinetic scheme(DUGKS)is developed for radiative transfer in anisotropic scattering media.The method is an extension of a previous one for isotropic radiation problems[1].The present scheme is a finite-volume discretization of the anisotropic gray radiation equation,where the anisotropic scattering phase function is approximated by the Legendre polynomial expansion.With the coupling of free transport and scattering processes in the reconstruction of the flux at cell interfaces,the present DUGKS has the nice unified preserving properties such that the cell size is not limited by the photon mean free path even in the optical thick regime.Several one-and two-dimensional numerical tests are conducted to validate the performance of the present DUGKS,and the numerical results demonstrate that the scheme is a reliable method for anisotropic radiative heat transfer problems.展开更多
基金Supported by the National Natural Science Foundation of China (60572015)
文摘In this paper, multipath temporal spreading distributions of laser pulses are calculated when they travel through the seawater. Individual photon is followed in Monte Carlo calculation A modified Henyey-Greenstein （HG） function is applied to represent the scattering phase function of seawater. This paper proposes a new scaling method, which uses the effective scattering thickness τd to replace the optical thickness used in the traditional scaling technique. This paper compares the temporal spreading distributions of photons on conditions of different attenuation coefficients and target depths. The experiments reveal that these mutual deviations are changing in the range from 0.5% to 5%, so long as the corresponding effective scattering thicknesses τd remains the same. Therefore, a conclusion can be obtained, that the temporal spreading distribution is only dependent on the effective diffusion thickness τd .
基金The National Key R&D Program of China(No.2018YFE0180900)the Fundamental Research Funds for the Central Universities(No.2019kfyXMBZ040).
文摘In this work,a discrete unified gas kinetic scheme(DUGKS)is developed for radiative transfer in anisotropic scattering media.The method is an extension of a previous one for isotropic radiation problems[1].The present scheme is a finite-volume discretization of the anisotropic gray radiation equation,where the anisotropic scattering phase function is approximated by the Legendre polynomial expansion.With the coupling of free transport and scattering processes in the reconstruction of the flux at cell interfaces,the present DUGKS has the nice unified preserving properties such that the cell size is not limited by the photon mean free path even in the optical thick regime.Several one-and two-dimensional numerical tests are conducted to validate the performance of the present DUGKS,and the numerical results demonstrate that the scheme is a reliable method for anisotropic radiative heat transfer problems.
