Constructal theory: From thermodynamic and geometric optimization to predicting shape in nature
Constructal theory: From thermodynamic and geometric optimization to predicting shape in nature
复制标题
DOI：
10.1016/s0196-8904(98)00054-5
复制
发表时间：
1998-11-01
影响因子：
10.4
通讯作者：
Bejan, A
中科院分区：
文献类型：
--
作者：
Bejan, A
这是一个最新的理论发展，以预测宏观组织（形状和结构的发生）在自然流动系统，有生命和无生命的回顾。出发点是如何优化一个点与有限体积（即无限个数的点）之间的访问问题。如果体积是一个均匀产生热量的电子设备，那么访问优化意味着体积和点大小的散热器之间的热阻最小。同样，如果体积必须在每个点上都有一个通道（例如，肺中的空气通道，或毛细血管床中的血流），最佳通道意味着体积和源或汇之间的流动阻力最小。主要的发现是纯粹几何的：这种复合材料的任何有限尺寸的部分都可以优化其形状，从而使其对Row的总体阻力最小。因此，通过在每个长度尺度上优化体积形状，从最小的建筑块（元素系统）开始，到更大的建筑块（组件、结构），从而获得总体积的最佳访问解决方案。解决方案是构造的，因此相关理论的名称是“构造的”。路径形成树形网络，其中每一个几何细节都是理论上确定的。当时间方向相反时，从大元素到小元素，树形网络无法从理论上确定。对于体积和一点之间的流体流动，区域和一点之间的最小时间旅行以及最小成本经济结构，进一步说明了构造原理。1998爱思唯尔科学有限公司版权所有。
This is a review of recent theoretical developments toward predicting macroscopic organization (the occurrence of shape and structure) in natural flow systems,animate and inanimate. The starting point is the question of how to optimize the access between one point and a finite volume (i.e., an infinite number of points). If the volume is an electronic device that generates heat uniformly, then access optimization means minimum thermal resistance between the volume and a point-size heat sink. Similarly, if the volume must be bathed at every point by a how (e.g., air Row in the lung, or blood flow in a capillary bed), optimal access means minimum flow resistance between the volume and a source or sink. The main discovery is purely geometric: any finite-size portion of this composite can have its shape optimized such that its overall resistance to Row is minimal. Consequently, the optimal-access solution for the total volume is obtained by optimizing volume shape at every length scale, in a sequence that begins with the smallest building block (elemental system), and proceeds toward larger building blocks (assemblies, constructs). The solution is constructed, hence the "constructal" name of the associated theory. The paths forma tree network in which every single geometric detail is determined theoretically. The tree network cannot be determined theoretically when the time direction is reversed, from large elements toward smaller elements. The constructal principle is further illustrated for fluid flow between a volume and one point, for minimum-time travel between an area and one point, and for minimum-cost economics structures. (C) 1998 Elsevier Science Ltd. All rights reserved.