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02846 Predicting the heating value of sewage sludges in thailand from proximate and ultimate analyses
16 Fuel science and technology (fundamental science, analysis, instrumentation) This work is focused on two ways of studying the reduction of the aerodynamic resistance of a van and the energy saving for a van with a dome. The first approach is the three dimensional (3-D) numerical simulation, and the other is the wind tunnel experiment. The relationship between the coefficient of aerodynamic resistance and the geometric parameters of the dome is obtained. The study also analysed the mechanism by which a dome can reduce the aerodynamic resistance acting on a van. Design for the improvement of a van can benefit from this work. The R N G k - e turbulence models are adopted in the computation. The momentum method is used to calculate the coefficient of resistance. These have resulted in improvement of the computation accuracy. Flow maps drawn on the basis of the computed results can offer a reliable method to study the flow field around a van. The computed results can give a reference for study o f the aerodynamic resistance reduction on a van for energy saving. The maximum decrease of the coefficient of aerodynamic resistance is 21.5% after a dome is installed on a van. The experiment also proves that the calculation using R N G k-e turbulence models is more accurate for such a separated fluid around a van. The error of the calculations using R N G k-e turbulence models is decreased by 6% compared with that using standard k-e turbulence models.
05•02841 Numerical study of partitions effect on multiplicity of solutions in an infinite channel periodically heated from below Abourida, B. and Hasnaoui, M. Energy Conversion and Management, 2005, 46, (17), 2697-2717. Laminar natural convection in an infinite horizontal channel heated periodically from below and provided with thin adiabatic partitions on its lower wall, is investigated numerically. The effect of these partitions on the multiplicity of solutions and heat transfer characteristics in the computational domain is studied. The parameters of the study are the Rayleigh number (102 < Ra < 4.9 x 106) and the height of the partitions (0 _< B = h~/H' <_ 1/2). The results obtained in the case of air (Pr = 0.72) as working fluid show that depending on the governing parameters, the existence of multiple solutions is possible. Important differences in terms of heat transfer are observed between two different solutions.
05•02842 On the mean number of collisions suffered by neutrons in bounded domains Mazzolo, A. Annals of Nuclear Energy, 2005, 32, (6), 549-557. The mean number of collisions suffered by monoenergetic neutrons starting from a random point on or inside :a purely scattering bounded convex or non-convex domain is derived. For trajectories starting on the surface and entering the body with an isotropic uniform incidence, the average number of collisions is independent of the scattering law. Monte-Carlo simulations illustrate the results in two- and threedimensions.
05102843 Parametric analysis of the neutron transmutation doping (NTD) facility at the Egyptian Second Research Reactor (ETRR-2) K_halil, IVl. Y. et at. Annals of Nuclear Energy, 2005, 32, (3), 355-365. One of the most important facilities of the Egyptian Second Research Reactor (ETRR-2) is the silicon Neutron Transmutation Doping (NTD) Facility. This work is done to optimize the performance of the ETRR-2 NTD facility based on the standards and to develop a calculation line that can be used during its commercial operating phase. Calculation line methodology was developed using WIMS-D4 and CITVAP codes as well as nuclear data file libraries to perform core calculations needed to predict neutronic parameters at the two NTD locations. Axial flux profile was calculated and results were in good agreement with the experimental flttx mapping. Based on the calculated variation of the thermal neutron flux axial distribution, it was proposed to displace the silicon ingot axially from its initially proposed position to minimize flux variation. Impact of control rod configuration was analysed to maximize the neutron flux at the NTD two locations and the best control rod configuration is recommended. Thermal to fast neutron flux was also calculated and concluded that radiation damage caused by fast neutrons can safely be neglected. Flux depression across the ingot was estimated using the ANISN code. Finally, the SIMULINK module of the MATLAB code was used to evaluate the ingot activity due to different radioactive nuclides. The activity was found to reach its exempted limit after 2.79 days after its discharge from the irradiation channel. It was also concluded that the worse ETRR-2 scram will not affect the obtained Si doping and its resistivity.
05•02844
Particle flux in an annular gap about a sphere
Cassell, J. S. and Williams, M. M. R. Annals of Nuclear Energy, 2005, 32, (5), 457-478. This study developed a method for joining diffusion theory to a void region in a consistent manner. In particular, the theory was applied to a three region problem with a central soiid core, surrounded by a
412
Fuel and Energy Abstracts
November 2005
concentric void shell and this in turn is surrounded by a concentric shell of another solid material. The sources can be either incident on the outer surface or uniformly distributed in the inner and outer regions. The void flux is calculated from the free streaming Boltzmann equation and is linked to the diffusion equations by assuming that the angular distribution on the surfaces follows the form A + B cos, where A and B are related to the diffusion theory fluxes in the inner and outer regions. This procedure allows us to calculate the flux throughout the solid and void regions without making any diffusion theory assumptions in the void. Numerical results are given to illustrate the method and comparisons with exact transport calculations are given to establish the accuracy. An extension of the method to deal with axially symmetric systems is also given in Appendix B. The theory will apply to neutrons and photons.
05/02845 Performance study of a magnetohydrodynamic accelerator using air-plasma as working gas Anwari, M. et al. Energy Conversion and Management, 2005, 46, (1516), 2605-2613. The fundamental performance of a linear Faraday type magnetohydrodynamic (MHD) accelerator under chemical and thermal equilibrium conditions is studied in this paper. Quasi-one dimensional numerical simulation is performed to characterize acceleration along the specified channel. In order to solve the set of differential equations of magnetohydrodynamics, the MacCormack scheme is employed. In this present calculation, a working gas of air-plasma, consisting of diatomic molecules of nitrogen, oxygen and hydrogen, is considered in order to actualize application of the M H D accelerator propulsion system. Numerical results show the characteristics of flow velocity, gas temperature and electrical conductivity of the MHD accelerator with the working gas of air-plasma. The computations are compared with numerical simulation results using the inert gas of argon evaluated in past studies.
05•02846 Predicting the heating value of sewage sludges in Thailand from proximate and ultimate analyses Thipkhunthod, P. et al. Fuel, 2005, 84, (7-8), 849-857. There have been various methods used for determining a heating value of solid fuel such as coal, biomass and municipal solid waste either by experiment using a bomb calorimeter or by modeling based on its compositions. This work proposes another aspect in developing models to predict the heating value of sewage sludge from its proximate and ultimate analyses data. The extensive number of samples was collected from different wastewater treatment plants in Bangkok and in the vicinity and was then analysed for their heating values, proximate and ultimate analyses. Based upon proximate and ultimate analyses, the models were proposed. The best results show coefficients of determination (R 2) of 0.899 and 0.905 for the models based on the proximate and ultimate analyses, respectively. The heating values obtained from the models were in good agreement with that attained by experiment. The application of the selected models was appreciable for the sewage sludge with ash content up to 50% (db).
05/02847 Prediction of force-deflection behaviour of pressurised pipes subjected to axially long radial indentation Hyde, T. H. et al. International Journal of Pressure Vessels' and Piping, 2005, 82, (8), 625-637. The force-deflection behaviour of pressurised pipes, due to radial indentation loading, was investigated using finite element (FE) and analytical methods. Seven different materials, three different pipe geometries, seven different pressure levels and five different support conditions were used to investigate their effects on the force-deflection behaviour. The comparisons of the FE and analytical solutions indicate that an energy-based, analytical approach can accurately predict the force-deflection behaviour in both the elastic and elastic-plastic states.
05/02848 Radiation shielding calculations for the vista spacecraft Sahin, S. et al. Energy Conversion and Management, 2005, 46, (15-16), 2345-2358. The VISTA spacecraft design concept has been proposed for manned or heavy cargo deep space missions beyond earth orbit with inertial fusion energy propulsion. Rocket propulsion is provided by fusion power deposited in the inertial confined fuel pellet debris and with the help of a magnetic nozzle. The calculations for the radiation shielding have been revised under the fact that the highest jet efficiency of the vehicle could be attained only if the propelling plasma would have a narrow temperature distribution. The shield mass could be reduced from 600 tons in the original design to 62 tons. Natural and enriched lithium were the principle shielding materials. The allowable nuclear heating in the superconducting magnet coils (up to 5 mW/cm 3) is taken as the crucial criterion for dimensioning the radiation shielding structure of the spacecraft. The space craft mass is 6000 tons. Total peak nuclear power density in the coils is calculated as ~5.0 mW/cm 3
05•02841 Numerical study of partitions effect on multiplicity of solutions in an infinite channel periodically heated from below Abourida, B. and Hasnaoui, M. Energy Conversion and Management, 2005, 46, (17), 2697-2717. Laminar natural convection in an infinite horizontal channel heated periodically from below and provided with thin adiabatic partitions on its lower wall, is investigated numerically. The effect of these partitions on the multiplicity of solutions and heat transfer characteristics in the computational domain is studied. The parameters of the study are the Rayleigh number (102 < Ra < 4.9 x 106) and the height of the partitions (0 _< B = h~/H' <_ 1/2). The results obtained in the case of air (Pr = 0.72) as working fluid show that depending on the governing parameters, the existence of multiple solutions is possible. Important differences in terms of heat transfer are observed between two different solutions.
05•02842 On the mean number of collisions suffered by neutrons in bounded domains Mazzolo, A. Annals of Nuclear Energy, 2005, 32, (6), 549-557. The mean number of collisions suffered by monoenergetic neutrons starting from a random point on or inside :a purely scattering bounded convex or non-convex domain is derived. For trajectories starting on the surface and entering the body with an isotropic uniform incidence, the average number of collisions is independent of the scattering law. Monte-Carlo simulations illustrate the results in two- and threedimensions.
05102843 Parametric analysis of the neutron transmutation doping (NTD) facility at the Egyptian Second Research Reactor (ETRR-2) K_halil, IVl. Y. et at. Annals of Nuclear Energy, 2005, 32, (3), 355-365. One of the most important facilities of the Egyptian Second Research Reactor (ETRR-2) is the silicon Neutron Transmutation Doping (NTD) Facility. This work is done to optimize the performance of the ETRR-2 NTD facility based on the standards and to develop a calculation line that can be used during its commercial operating phase. Calculation line methodology was developed using WIMS-D4 and CITVAP codes as well as nuclear data file libraries to perform core calculations needed to predict neutronic parameters at the two NTD locations. Axial flux profile was calculated and results were in good agreement with the experimental flttx mapping. Based on the calculated variation of the thermal neutron flux axial distribution, it was proposed to displace the silicon ingot axially from its initially proposed position to minimize flux variation. Impact of control rod configuration was analysed to maximize the neutron flux at the NTD two locations and the best control rod configuration is recommended. Thermal to fast neutron flux was also calculated and concluded that radiation damage caused by fast neutrons can safely be neglected. Flux depression across the ingot was estimated using the ANISN code. Finally, the SIMULINK module of the MATLAB code was used to evaluate the ingot activity due to different radioactive nuclides. The activity was found to reach its exempted limit after 2.79 days after its discharge from the irradiation channel. It was also concluded that the worse ETRR-2 scram will not affect the obtained Si doping and its resistivity.
05•02844
Particle flux in an annular gap about a sphere
Cassell, J. S. and Williams, M. M. R. Annals of Nuclear Energy, 2005, 32, (5), 457-478. This study developed a method for joining diffusion theory to a void region in a consistent manner. In particular, the theory was applied to a three region problem with a central soiid core, surrounded by a
412
Fuel and Energy Abstracts
November 2005
concentric void shell and this in turn is surrounded by a concentric shell of another solid material. The sources can be either incident on the outer surface or uniformly distributed in the inner and outer regions. The void flux is calculated from the free streaming Boltzmann equation and is linked to the diffusion equations by assuming that the angular distribution on the surfaces follows the form A + B cos, where A and B are related to the diffusion theory fluxes in the inner and outer regions. This procedure allows us to calculate the flux throughout the solid and void regions without making any diffusion theory assumptions in the void. Numerical results are given to illustrate the method and comparisons with exact transport calculations are given to establish the accuracy. An extension of the method to deal with axially symmetric systems is also given in Appendix B. The theory will apply to neutrons and photons.
05/02845 Performance study of a magnetohydrodynamic accelerator using air-plasma as working gas Anwari, M. et al. Energy Conversion and Management, 2005, 46, (1516), 2605-2613. The fundamental performance of a linear Faraday type magnetohydrodynamic (MHD) accelerator under chemical and thermal equilibrium conditions is studied in this paper. Quasi-one dimensional numerical simulation is performed to characterize acceleration along the specified channel. In order to solve the set of differential equations of magnetohydrodynamics, the MacCormack scheme is employed. In this present calculation, a working gas of air-plasma, consisting of diatomic molecules of nitrogen, oxygen and hydrogen, is considered in order to actualize application of the M H D accelerator propulsion system. Numerical results show the characteristics of flow velocity, gas temperature and electrical conductivity of the MHD accelerator with the working gas of air-plasma. The computations are compared with numerical simulation results using the inert gas of argon evaluated in past studies.
05•02846 Predicting the heating value of sewage sludges in Thailand from proximate and ultimate analyses Thipkhunthod, P. et al. Fuel, 2005, 84, (7-8), 849-857. There have been various methods used for determining a heating value of solid fuel such as coal, biomass and municipal solid waste either by experiment using a bomb calorimeter or by modeling based on its compositions. This work proposes another aspect in developing models to predict the heating value of sewage sludge from its proximate and ultimate analyses data. The extensive number of samples was collected from different wastewater treatment plants in Bangkok and in the vicinity and was then analysed for their heating values, proximate and ultimate analyses. Based upon proximate and ultimate analyses, the models were proposed. The best results show coefficients of determination (R 2) of 0.899 and 0.905 for the models based on the proximate and ultimate analyses, respectively. The heating values obtained from the models were in good agreement with that attained by experiment. The application of the selected models was appreciable for the sewage sludge with ash content up to 50% (db).
05/02847 Prediction of force-deflection behaviour of pressurised pipes subjected to axially long radial indentation Hyde, T. H. et al. International Journal of Pressure Vessels' and Piping, 2005, 82, (8), 625-637. The force-deflection behaviour of pressurised pipes, due to radial indentation loading, was investigated using finite element (FE) and analytical methods. Seven different materials, three different pipe geometries, seven different pressure levels and five different support conditions were used to investigate their effects on the force-deflection behaviour. The comparisons of the FE and analytical solutions indicate that an energy-based, analytical approach can accurately predict the force-deflection behaviour in both the elastic and elastic-plastic states.
05/02848 Radiation shielding calculations for the vista spacecraft Sahin, S. et al. Energy Conversion and Management, 2005, 46, (15-16), 2345-2358. The VISTA spacecraft design concept has been proposed for manned or heavy cargo deep space missions beyond earth orbit with inertial fusion energy propulsion. Rocket propulsion is provided by fusion power deposited in the inertial confined fuel pellet debris and with the help of a magnetic nozzle. The calculations for the radiation shielding have been revised under the fact that the highest jet efficiency of the vehicle could be attained only if the propelling plasma would have a narrow temperature distribution. The shield mass could be reduced from 600 tons in the original design to 62 tons. Natural and enriched lithium were the principle shielding materials. The allowable nuclear heating in the superconducting magnet coils (up to 5 mW/cm 3) is taken as the crucial criterion for dimensioning the radiation shielding structure of the spacecraft. The space craft mass is 6000 tons. Total peak nuclear power density in the coils is calculated as ~5.0 mW/cm 3