In this paper, the typical exponential method, diamond difference and modified time discrete scheme is researched for self adaptive time step. The second-order time evolution scheme is applied to time-dependent spherical neutron transport equation by discrete ordinates method. The numerical results show that second-order time evolution scheme associated exponential method has some good properti...

In this work concerning steady-state radiative-transfer calculations in plane-parallel media, the equivalence between the discrete ordinates method and the spherical harmonics method is proved. More specifically, it is shown that for standard radiative-transfer problems without the imposed restriction of azimuthal symmetry the two methods yield identical results for the radiation intensity when...

in this paper, a new systematic design methodology has been developed for thes imultaneous energy and water minimization in multiple-contaminant systems that also feature maximum re-use of water. in addition to allowing re-use of water in multiple-contaminant systems, issues about heat losses and flowrate changes inside unit operations have also been incorporated in this new design method. to i...

An analytical version of the discrete-ordinates method (the ADO method) is used to establish concise and particularly accurate solutions to the viscous-slip and the half-space thermal-creep problems for a binary gas mixture. The kinetic equations used to describe the flow are based on the McCormack model for mixtures. In addition to a computation of the viscous-slip and thermal-slip coefficient...

In this study, the thermal performance analysis of porous fin with temperature-dependent thermal conductivity and internal heat generation is carried out using Haar wavelet collocation method. The effects of various parameters on the thermal characteristics of the porous fin are investigated. It is found that as the porosity increases, the rate of heat transfer from the fin increases and the th...

pinch technology is one of the best methods for designing a multi stream heat exchanger(mshe) through a network; current pinch-based methods, however, lead to a larger and more complicateddesign problems. the major drawback of the current methods is they result in designs having more individual mshe sections than essential, correspond to the enthalpy intervals on temperature vs. enthalpy diagra...

water and energy are key commodities utilized in the process industries.water minimization and energy minimization have been studied separately. in this paper, a new systematic design methodology has been developed for the simultaneous management of energy and water systems that also feature maximum re-use of water. in addition to allowing re-use of water, issues about heat losses inside unit o...