effective diameter of pipe

例句：

1. 1. The new design has a much larger effective diameter for better performance.
   新设计具有更大的有效直径，以获得更好的性能。
2. 2.The engine's effective diameter is 30 cm, which is significantly larger than the standard model.
   发动机的有效直径为30厘米，比标准型号大很多。
3. 3. The new machine has an effective diameter of 10 mm, making it more compact and efficient.
   新型机器的有效直径为10毫米，使其更加紧凑且高效。