diffuser cone meaning in English

扩散器锥管
扩散器锥体

The 2 stroke book says because of testing , an 8 degree angle of divergence for the diffuser cone connected to the lead in pipe is the minimum angle to start with and 20 degrees for the compression cone at the other end of the pipe is a good starting point
二行程手册测试,一个八度的渐缩圆锥反射角,连接导入气管通道,是一个极小的开始角度,以及20度的压缩圆锥在气管的另一结束端,是一个好的开始