Comparison on the hydraulic and thermal performances of two tree-like channel networks with different size constraints

The present work investigates and compares the hydraulic and thermal performances of two tree-like networks with constant surface area constraint and constant volume constraint. The results find that the optimal channel diameter ratio to reach a minimum hydraulic resistance satisfies beta(m) = N-2/5 for the tree-like network with surface area constraint, but beta(m) = N-1/3 for the tree-like network with volume constraint. The convective heat transfer in both of the two tree-like networks with different size constraints is independent on the channel diameter and diameter ratio, but increases with the increasing channel length, channel length ratio, branching level and branching number. For the two tree-like networks with exactly the same channel length, length ratio, branching number and branching level but different channel diameter, the present work provides a segmenting model to choose the network with better hydraulic and thermal performances. (C) 2018 Elsevier Ltd. All rights reserved.

本研究对具有恒定表面积约束和恒定体积约束的两种树状网络的水力和热性能进行了研究和比较。结果发现，对于具有表面积约束的树状网络，达到最小水力阻力的最佳通道直径比满足β(m)=N - 2/5，而对于具有体积约束的树状网络，β(m)=N - 1/3。在具有不同尺寸约束的两种树状网络中，对流传热均与通道直径和直径比无关，但随通道长度、通道长度比、分支级数和分支数量的增加而增加。对于通道长度、长度比、分支数量和分支级数完全相同但通道直径不同的两种树状网络，本研究提供了一个分割模型来选择具有更好水力和热性能的网络。（C）2018爱思唯尔有限公司。保留所有权利。