障碍物遮挡率对水面蒸发量的影响浅析

为保证水面蒸发量观测精度,准确进行水资源评价、水量平衡计算,根据芒市大河木康水文站水面蒸发量观测场迁站前后的年水面蒸发量进行统计分析,研究迁站后因障碍物遮挡率的增加对水面蒸发量的影响程度。分析得出:当水面蒸发量观测场遮挡率超过15%时,应进行误差订正,把障碍物遮挡率对器测水面蒸发量的影响控制在10%以内,保证水面蒸发量的观测精度。

基于栅格地图改进的智能路径选择算法

交通和物流领域的发展,对路径规划算法的时间复杂度与精度提出了越来越高的要求。针对该问题,提出了一种基于栅格地图改进的智能路径选择算法。该算法利用方向信息来对算法进行优化设计,基于原有地图带有的始末位置的方向信息,定义权值矩阵与方向权重向量,以此作为路径中下个栅格的选择依据,并采取奖励与惩罚措施来提高算法的收敛速度。此外,算法还采取了多余栅格的优化措施来提高算法性能。通过对于典型仓储AVG问题模型的仿真来验证算法的有效性。结果表明,路径长度收敛到满足条件的较优解所需的时间,智能路径选择算法较A;算法及传统Dijkstra算法可以减少10%以上,具有较低的时间复杂度和较高的寻优效率。

A Comparative Study of the Local Heat Transfer Distributions Around Various Surface Mounted Obstacles

In many engineering applications,heat transfer enhancement techniques are of vital importance in order to ensure reliable thermal designs of convective heat transfer applications.This study examines experimentally the heat transfer characteristics on the base plate around various surface mounted obstacles.Local convection coefficients are evaluated in the vicinity of each individual protruding body with great spatial resolution using the transient liquid crystal technique.Five different obstacles of constant height-to-hydraulic diameter ratio(~1.3) are considered.These include:a cylinder,a square,a triangle,a diamond and a vortex generator of delta wing shape design.The experiments were carried out over a range of freestream Reynolds numbers,based on the hydraulic diameter of each obstacle,varying from 4,000 to 13,000.The results indicate a negligible effect of the flow speed on the heat transfer topological structure and a considerable effect of the obstacle geometry on the level and distribution of heat transfer enhancement.