【摘要】 本文对于决定湍流及层流区最经济管径（总费用最低）的公式进行了推导，而且把它制成了便 于应用的算图。联解临界雷纳准数及最适宜直径方程式，得到一个便于预先决定流型的关系式。本 文所推导的公式及算图都是以我国目前的价格指标为依据，因此应用它来选取经济管径应当是适合 于我国情况的。更多还原

【Abstract】 In this article equations for evaluating the most economical pipe diameter, for which the sum of pipe and pumping costs must be a mininum. have been derived for the turbu- lent at well a, the viscous regions of flow. The retulting equations are represented by convenient nomographs. By solving the optimum -- diameter equations for the case of critical Reynold number, it has been found possible to decide whether any given flow will be turbulent or viscous in a pipe of optimum diameter. At these equations and charts are all based on the Present cost index of our country, they are expecied to be more usefol in the choice of the most economical pipe diametr in our country.更多还原