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2.
The present work focuses on a two‐dimensional steady incompressible stagnation point flow of a Jeffery fluid over a stretching sheet. The Cattaneo‐Christov heat flux model is incorporated into this study. Simulation is conducted via the Runge‐Kutta fourth‐order cum shooting method for the transformed system of nonlinear equations. The influence of the governing parameters on the dimensionless velocity, temperature, skin friction, streamlines, and isotherms is incorporated. A significant outcome of the current investigation is that an increase in the relaxation time parameter uplifts temperature; however, a gradual decrease is observed in the velocity field. Another important outcome of the present analysis is that the momentum boundary layer augments due to an increase in the Deborah number; however, a decrease is observed in the temperature. Furthermore, it is also observed that the skin friction coefficient escalates with an increase in the relaxation time parameter for the assisting flow, but a reverse trend is observed for the opposing flow. 相似文献
3.
The scheduling process of cracking furnace feedstock is important in an ethylene plant. In this paper it is described as a constraint optimization problem. The constraints consist of the cycle of operation, maximum tube metal temperature, process time of each feedstock, and flow rate. A modified group search optimizer is pro-posed to deal with the optimization problem. Double fitness values are defined for every group. First, the factor of penalty function should be changed adaptively by the ratio of feasible and general solutions. Second, the“excel-lent”infeasible solution should be retained to guide the search. Some benchmark functions are used to evaluate the new algorithm. Final y, the proposed algorithm is used to optimize the scheduling process of cracking furnace feedstock. And the optimizing result is obtained. 相似文献
4.
体能监控仪作为生命体征监测设备,对于辅助大学生完成体能训练有很大帮助;基于STM32单片机技术,设计开发集成了多种传感器的一种大学生体能监测装备,它能够有效的检测包括心率检测、人体的步数、运动圈速、消耗卡路里等信息;该设计采用了STM32作为主控芯片,采用模块化的设计思路;在系统硬件设计方面,设计了包括STM32控制系统、心率获取电路、三轴传感器电路、显示电路以及按键电路等;同时将软件模块拆分成了初始化子程序、心率获取子程序,步数获取子程序,显示子程序等;Proteus仿真结果显示,使用STM32单片机技术设计的体能监测系统,能够运行稳定,测量心率范围60次/min~180次/min,可在心率异常时报警,同时检测步数的准确率达98%,满足体能监测任务需要,实验结果符合预期;为STM32单片机在体育运动研究信息化中应用提供参考。 相似文献
5.
6.
为响应全民健身战略与体育强国建设政策,从用地
比例、项目内容两方面,提出不同类别城市公园体育健身功能
的更新策略。1)以北京城市公园为例,分析当前公园绿地体
育健身功能现状,明晰问题。2)对比国内外一线地区公园体
育健身功能建设,寻找差距。3)综合国内外优秀建设经验,
将公园分为三大类:游园和社区公园(小于5hm2
)、社区公园
和小型综合公园(5~20hm2
)、大型综合公园和郊野公园(大于
20hm2
),分别提出更新策略。分析得出,城市公园用地具备
承载更多体育健身功能的潜力。应对公园建设情况进行灵活评
估,适度提升体育健身用地比例,并根据公园规模、使用者年
龄结构等要素,丰富公园用地所承载的体育健身项目内容。 相似文献
7.
M. Sreedhar Babu Velpula V. Ramana G. Ravisankar C. S. K. Raju M. N. Bashir Sabir A. Shehzad 《亚洲传热研究》2020,49(8):4226-4245
In this investigation, the flow of an unsteady mixed convection boundary layer viscous nanofluid on a stretchable sheet is considered. The flow examination is affected by a magnetic field. The reason for the examination exhibited is to create models for nanomaterials that incorporate the Brownian movement and thermophoresis phenomena. The created nonlinear standard differential condition is illuminated numerically utilizing the Runge-Kutta-Gill technique and the start program. The different factors of speed, temperature, and concentration are reported and discussed. The examination shows that the speed, temperature, and concentration are lower in contrast with the consistent stream on account of an assisting flow, whereas the opposite situation is noticed in the opposing flow case. The effects of Brownian movement and thermophoresis in the concentration case are totally different. 相似文献
8.
An unsteady stagnation point flow of a Maxwell fluid over a unidirectional linearly stretching sheet is studied under the influence of a magnetic field. The parabolic energy equation, which is based on parabolic Fourier law is replaced with a hyperbolic energy equation incorporating the heat flux model of Cattaneo–Christov. The Buongiorno model is used to characterize the properties of nanofluids using thermophoresis and Brownian diffusion coefficients. The phenomenon of melting heat transfer and slip mechanism is also embodied in the present study. Coupled nonlinear differential equations have appeared when the specified similarity transformations are applied. The mathematical problem is tackled via the homotopy analysis method. The impact of important physical parameters on the velocity, concentration, and temperature are highlighted via graphs. To verify our present results, a comparison is given with a limiting case with an already published article. It is witnessed through the graphs that the higher unsteadiness parameter and melting heat coefficient both are responsible for the reduction in the velocity and temperature of the nanofluid. Also, the velocity slip parameter detracts the velocity profile and affiliated boundary layer thickness of the Maxwell nanofluid. 相似文献
9.
The job execution mechanism of Spark was analyzed,task efficiency model and Shuffle model were established,then allocation fitness degree (AFD) was defined and the optimization goal was put forward.On the basis of the model definition,the progressive filling partitioning and mapping algorithm (PFPM) was proposed.PFPM established the data distribution scheme adapting Reducers’ computing ability to decrease synchronous latency during Shuffle process and increase cluster the computing efficiency.The experiments demonstrate that PFPM could improve the rationality of workload distribution in Shuffle and optimize the execution efficiency of Spark. 相似文献
10.