Influence of Injection Patten on the Action of Drag Reducing Agent

Injection patten is an important part in the practical technique of drag reducing agent. The paper collects some information of different pattens of drag reducing agent in foreign countries and introluces these different pattens which have influence on the effect of drag reducing and have improvement for the injection units of practical drag reducing agent. It also analyzes and compares the economic efficiency of three different injection pattens.