In the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional heating.The two-dimensional boundary layer momentum and energy equations...In the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional heating.The two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity transformations.The set of resultant ordinary differential equations are solved numerically.The numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan number.The velocity profile f'(ξ),temperature distributionθ(ξ),entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in detail.Further,for the sake of validation of our numerical code,the obtained results are reproduced using Matlab built-in boundary value solver bvp4c resulting in an excellent agreement.It is observed that entropy generation is increasing function of heating parameter,Prandtl number,Eckert number and radiation parameter.Further,it is observed that entropy generation can be minimized by reducing the operating temperatureΔT=T_(w)−T_(∞).展开更多
We present the preliminary results of our code OPAQS（opacity calculation using quantum statistical model） that is based on the self consistent Hartree-Fock-Slater model for the average atom. The code is capable of p...We present the preliminary results of our code OPAQS（opacity calculation using quantum statistical model） that is based on the self consistent Hartree-Fock-Slater model for the average atom. The code is capable of performing robust calculations of average charge state, frequency-dependent and mean opacities. The accuracy of the atomic model is verified by comparing the calculations of average charge state with various published results. The monochromatic opacities for iron computed at different sets of temperatures and densities are compared with LEDCOP. The Rosseland and Planck opacities for iron and aluminum are validated with some state-of-the-art codes. The results are in good agreement with the published data.展开更多
A screened hydrogenic model for 1 splitting （SHML） is used to calculate the Rosseland mean opacities of high-Z Au, Ta, Yb, Ho, C-d, Sm, Nd, Sn, Ag plasmas and mixtures of gold and these elements at high temperature ...A screened hydrogenic model for 1 splitting （SHML） is used to calculate the Rosseland mean opacities of high-Z Au, Ta, Yb, Ho, C-d, Sm, Nd, Sn, Ag plasmas and mixtures of gold and these elements at high temperature （ T = 200 - 400 eV） and dense （ρ= 1 g/cm^3）. From the calculated Rosseland mean opacities of the mixtures, Au-Nd seems to be a better choice than other mixtures. Simultaneously, the reason that the mean opacities of mixture of Au-Sn decrease slightly when T = 400 eV is analyzed.展开更多
The behavior of Li warm plasma (i.e. T in 1 eV range) is reported for a range of temperatures () and densities ( ), spanning moderate to dense conditions. Quantum Molecular Dynamics (QMD), in Carr-Parinello approach, ...The behavior of Li warm plasma (i.e. T in 1 eV range) is reported for a range of temperatures () and densities ( ), spanning moderate to dense conditions. Quantum Molecular Dynamics (QMD), in Carr-Parinello approach, is used to advance and equilibrate an ensemble of 54 Li atoms at desired temperature and density. The charge distribution and ions positions are further input in a DFT finite temperature calculation, producing, self consistently, a large number of energy levels (300 - 1500) and occupation numbers, from which real and imaginary parts of the dielectric function are obtained. Optical quantities like index of refraction, reflectivity, absorption coefficients and Rosseland means are deduced. Zero frequency static conductivity , diffusion coefficients and a Hugoniot curve are calculated.展开更多
文摘In the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional heating.The two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity transformations.The set of resultant ordinary differential equations are solved numerically.The numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan number.The velocity profile f'(ξ),temperature distributionθ(ξ),entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in detail.Further,for the sake of validation of our numerical code,the obtained results are reproduced using Matlab built-in boundary value solver bvp4c resulting in an excellent agreement.It is observed that entropy generation is increasing function of heating parameter,Prandtl number,Eckert number and radiation parameter.Further,it is observed that entropy generation can be minimized by reducing the operating temperatureΔT=T_(w)−T_(∞).
文摘We present the preliminary results of our code OPAQS（opacity calculation using quantum statistical model） that is based on the self consistent Hartree-Fock-Slater model for the average atom. The code is capable of performing robust calculations of average charge state, frequency-dependent and mean opacities. The accuracy of the atomic model is verified by comparing the calculations of average charge state with various published results. The monochromatic opacities for iron computed at different sets of temperatures and densities are compared with LEDCOP. The Rosseland and Planck opacities for iron and aluminum are validated with some state-of-the-art codes. The results are in good agreement with the published data.
基金Sponsored by the National Natural Science Foundation of China (10274055) the Natural Science Foundation of Southwest Universityfor Nation-alities of China (06NY003)
文摘A screened hydrogenic model for 1 splitting （SHML） is used to calculate the Rosseland mean opacities of high-Z Au, Ta, Yb, Ho, C-d, Sm, Nd, Sn, Ag plasmas and mixtures of gold and these elements at high temperature （ T = 200 - 400 eV） and dense （ρ= 1 g/cm^3）. From the calculated Rosseland mean opacities of the mixtures, Au-Nd seems to be a better choice than other mixtures. Simultaneously, the reason that the mean opacities of mixture of Au-Sn decrease slightly when T = 400 eV is analyzed.
文摘The behavior of Li warm plasma (i.e. T in 1 eV range) is reported for a range of temperatures () and densities ( ), spanning moderate to dense conditions. Quantum Molecular Dynamics (QMD), in Carr-Parinello approach, is used to advance and equilibrate an ensemble of 54 Li atoms at desired temperature and density. The charge distribution and ions positions are further input in a DFT finite temperature calculation, producing, self consistently, a large number of energy levels (300 - 1500) and occupation numbers, from which real and imaginary parts of the dielectric function are obtained. Optical quantities like index of refraction, reflectivity, absorption coefficients and Rosseland means are deduced. Zero frequency static conductivity , diffusion coefficients and a Hugoniot curve are calculated.
