一、无量纲乘积的计算方法 在量纲分析中,伯金汉(E.Buckingham)和以后的许多学者都给出了一个规则,即:在一全组中的无量纲乘积的数目等于其变数的总数减去问题中的基本量纲数,也就是π-定理。这是一个极为方便的规则,但有时会出错误的。在1922年布利格门(P.W.Bridgman)对于这一事实提醒人们注意。1946年范德里斯(Van Driest)叙述了下面的规则:在一全 I. THE METHOD OF CALCULATING THE NON-DIMENSIONAL PRODUCT In dimensional analysis, E. Buckingham and many others later gave the rule that the number of dimensionless products in a complete set is equal to its variable Minus the basic dimension of the problem, which is the π-theorem. This is a very handy rule, but sometimes it goes wrong. In 1922 P.W.Bridgman reminded people of this fact. In 1946 Van Driest recounted the following rules: In a whole