In this article, we answer the question of how to optimally design a rarefied gas distribution network from a source point to a given number of equidistant users such that the diameters of the pipes used to carry the fluid fall in the microscale. A slip boundary condition is used to take into account the effects introduced by the smallness of the pipes. By specifying the overall pressure drop across the network, we maximize the total mass flow rate through the dendritic structure under global volume constraint using an evolutionary algorithm. Four complexity levels are considered, nbif=0, 1, 2, and 3, where nbif is the number of levels of bifurcation present in the structure. The results show that the version of Murray’s law originally proposed in order to determine the optimal diameters of the pipes is not valid when rarefaction is present, since the power-law exponent varies significantly with the number of outlet users N. Additionally, the results show that the bifurcation angles decrease in the presence of rarefaction as N increases. The article ends by exploring the robustness of nonoptimized complex gas distribution networks.

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