流速由v<sub>1</sub>变到v<sub>2</sub>的突然扩大管,如分为两次扩大(如图所示),中间流速v取何值时,局部损失最小,此时局部损失h<sub>j2</sub>为多少,并与一次扩大时h<sub>j1</sub>比较。<br /> <img src="https://nimg.ppkao.com/2019-07/wuacheng/2019070717095296637.jpg?sign=edacfba6bdabeefab200af9c97fd98ec&t=62e4fb03" />
[]