[简答题]一般情况下黏度大的流体其Pr数也较大。由对流换热的实验关联式Nu=CRe^mPrⁿ可知(m＞0，n＞0) ，Pr数越大，Nu数也越大，从而换热系数h也越大，即黏度越大的流体其表面传热系数也越高。这与经验得出的结论相反，为什么？

Information channeling is undergoing remarkable progress in various sectors of society in industrial activities, public services and, more recently, in daily living.
In the sector of industrial activities, automation is continuing with the aim of increasing productivity--introduction of computers for process control by the manufacturing industry, and introduction of numerically controlled machine tools, industrial robots, computer-aided design systems and, more recently, flexible manufacturing system by processing and assembling industries.
(46) Meanwhile, in offices rapid office automation is presently in progress, stimulated by the popular acceptance of computerized systems, expansion of communications networks and the remarkable technological progress achieved in related equipment such as Japanese word processors. Rapid automation and efficiency improvement are also being achieved in the sector of commodity distribution through the introduction of advanc