A complete thermodynamic model is described for temperature and heat flow distribution simulation for ventilation networks in underground mines.The method is called the Computational Energy Dynamics(CED)model of the h...A complete thermodynamic model is described for temperature and heat flow distribution simulation for ventilation networks in underground mines.The method is called the Computational Energy Dynamics(CED)model of the heat,mass,and energy transport.The Thermal and Humidity(TH)transport elements of the full model are described for advection,convection,and accumulation,encompassing heat capacity,radiation,latent heat for evaporation,and condensation in the airways,as well as variable heat conduction and accumulation in the rock strata.The thermal flywheel effect for time-dependent temperature field applications is included in the model solution.A CED model validation exercise is described,directly evaluating the iterated,minimized energy balance errors for the mechanical and thermal energy components for each network branch after a converged solution is determined.A simulation example relevant to mine safety and health is shown with the CED-TH model,demonstrating its capabilities in efficiency and accuracy in comparison with measurement results.展开更多
Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provi...Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.展开更多
According to the high operating costs and a large number of energy waste in the current data center network architectures, we propose a kind of trusted flow preemption scheduling combining the energy-saving routing me...According to the high operating costs and a large number of energy waste in the current data center network architectures, we propose a kind of trusted flow preemption scheduling combining the energy-saving routing mechanism based on typical data center network architecture. The mechanism can make the network flow in its exclusive network link bandwidth and transmission path, which can improve the link utilization and the use of the network energy efficiency. Meanwhile, we apply trusted computing to guarantee the high security, high performance and high fault-tolerant routing forwarding service, which helps improving the average completion time of network flow.展开更多
Recent advancements of the intelligent transportation system(ITS)provide an effective way of improving the overall efficiency of the energy management strategy(EMSs)for autonomous vehicles(AVs).The use of AVs possesse...Recent advancements of the intelligent transportation system(ITS)provide an effective way of improving the overall efficiency of the energy management strategy(EMSs)for autonomous vehicles(AVs).The use of AVs possesses many advantages such as congestion control,accident prevention,and etc.However,energy management and traffic flow prediction(TFP)still remains a challenging problem in AVs.The complexity and uncertainties of driving situations adequately affect the outcome of the designed EMSs.In this view,this paper presents novel sustainable energy management with traffic flow prediction strategy(SEM-TPS)for AVs.The SEM-TPS technique applies type II fuzzy logic system(T2FLS)energy management scheme to accomplish the desired engine torque based on distinct parameters.In addition,the membership functions of the T2FLS scheme are chosen optimally using the barnacles mating optimizer(BMO).For accurate TFP,the bidirectional gated recurrent neural network(Bi-GRNN)model is used in AVs.A comprehensive experimental validation process is performed and the results are inspected with respect to several evaluation metrics.The experimental outcomes highlighted the supreme performance of the SEM-TPS technique over the recent state of art approaches.展开更多
The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces app...The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces applied on the collector’s body. To accomplish these goals a 2D modeling of CTC was carried out using commercial codes with various wind velocities and collector orientations. Ambient temperature was assumed to be constant at 300 K and for specific geometries different meshing methods and boundary conditions were used in various runs. Validation was done by comparing the simulation results for a horizontal collector with empirical data. It was observed that maximum force of 509.1 Newton per Meter occurs at +60 degrees. Nusselt number is almost the constant for positive angles while at negative angles it varies considerably with the collector’s orientation.展开更多
多能流计算是综合能源系统(integrated energy system,IES)分析和优化的基础。在各能源网络运营主体交互信息有限的背景下,为提升多能流计算的收敛性和计算效率,提出一种基于幂级数系数分向传递的递归型电-气-热多能流算法。首先,分别...多能流计算是综合能源系统(integrated energy system,IES)分析和优化的基础。在各能源网络运营主体交互信息有限的背景下,为提升多能流计算的收敛性和计算效率,提出一种基于幂级数系数分向传递的递归型电-气-热多能流算法。首先,分别建立电、气、热能源系统的全纯嵌入能流模型;其次,分析全纯嵌入法在多能流计算中的递归求解原理,将幂级数系数的传递划分为横向传递与纵向传递两类,建立可分向传递求解的电-气-热IES全纯嵌入多能流模型;接着,推导各全纯嵌入状态量的幂级数系数递归关系,通过幂级数系数的分向传递,递归求取状态量的幂级数系数,实现电-气-热多能流求解;最后,算例结果表明,所提方法能够以少量的交互信息实现多能流计算,具有更优的收敛性能和计算效率。展开更多
基金the Alpha Foundation for the Improvement of Mine Safety and Health,Inc.National Institute of Occupational Safety and Health(NIOSH)
文摘A complete thermodynamic model is described for temperature and heat flow distribution simulation for ventilation networks in underground mines.The method is called the Computational Energy Dynamics(CED)model of the heat,mass,and energy transport.The Thermal and Humidity(TH)transport elements of the full model are described for advection,convection,and accumulation,encompassing heat capacity,radiation,latent heat for evaporation,and condensation in the airways,as well as variable heat conduction and accumulation in the rock strata.The thermal flywheel effect for time-dependent temperature field applications is included in the model solution.A CED model validation exercise is described,directly evaluating the iterated,minimized energy balance errors for the mechanical and thermal energy components for each network branch after a converged solution is determined.A simulation example relevant to mine safety and health is shown with the CED-TH model,demonstrating its capabilities in efficiency and accuracy in comparison with measurement results.
基金supported by the Higher Committee for Education Development(HCED)in Iraq
文摘Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.
基金supported by the National Natural Science Foundation of China(The key trusted running technologies for the sensing nodes in Internet of things: 61501007The outstanding personnel training program of Beijing municipal Party Committee Organization Department (The Research of Trusted Computing environment for Internet of things in Smart City: 2014000020124G041
文摘According to the high operating costs and a large number of energy waste in the current data center network architectures, we propose a kind of trusted flow preemption scheduling combining the energy-saving routing mechanism based on typical data center network architecture. The mechanism can make the network flow in its exclusive network link bandwidth and transmission path, which can improve the link utilization and the use of the network energy efficiency. Meanwhile, we apply trusted computing to guarantee the high security, high performance and high fault-tolerant routing forwarding service, which helps improving the average completion time of network flow.
基金This work was supported by Taif University Researchers Supporting Program(project number:TURSP-2020/195),Taif University,Saudi Arabia.
文摘Recent advancements of the intelligent transportation system(ITS)provide an effective way of improving the overall efficiency of the energy management strategy(EMSs)for autonomous vehicles(AVs).The use of AVs possesses many advantages such as congestion control,accident prevention,and etc.However,energy management and traffic flow prediction(TFP)still remains a challenging problem in AVs.The complexity and uncertainties of driving situations adequately affect the outcome of the designed EMSs.In this view,this paper presents novel sustainable energy management with traffic flow prediction strategy(SEM-TPS)for AVs.The SEM-TPS technique applies type II fuzzy logic system(T2FLS)energy management scheme to accomplish the desired engine torque based on distinct parameters.In addition,the membership functions of the T2FLS scheme are chosen optimally using the barnacles mating optimizer(BMO).For accurate TFP,the bidirectional gated recurrent neural network(Bi-GRNN)model is used in AVs.A comprehensive experimental validation process is performed and the results are inspected with respect to several evaluation metrics.The experimental outcomes highlighted the supreme performance of the SEM-TPS technique over the recent state of art approaches.
文摘The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces applied on the collector’s body. To accomplish these goals a 2D modeling of CTC was carried out using commercial codes with various wind velocities and collector orientations. Ambient temperature was assumed to be constant at 300 K and for specific geometries different meshing methods and boundary conditions were used in various runs. Validation was done by comparing the simulation results for a horizontal collector with empirical data. It was observed that maximum force of 509.1 Newton per Meter occurs at +60 degrees. Nusselt number is almost the constant for positive angles while at negative angles it varies considerably with the collector’s orientation.
文摘多能流计算是综合能源系统(integrated energy system,IES)分析和优化的基础。在各能源网络运营主体交互信息有限的背景下,为提升多能流计算的收敛性和计算效率,提出一种基于幂级数系数分向传递的递归型电-气-热多能流算法。首先,分别建立电、气、热能源系统的全纯嵌入能流模型;其次,分析全纯嵌入法在多能流计算中的递归求解原理,将幂级数系数的传递划分为横向传递与纵向传递两类,建立可分向传递求解的电-气-热IES全纯嵌入多能流模型;接着,推导各全纯嵌入状态量的幂级数系数递归关系,通过幂级数系数的分向传递,递归求取状态量的幂级数系数,实现电-气-热多能流求解;最后,算例结果表明,所提方法能够以少量的交互信息实现多能流计算,具有更优的收敛性能和计算效率。
