Comparisons between various lengths of penstock and different types of waterhammer using circuit equivalent method and characteristic method are presented by digital simulation. 最後對不同類型水擊和不同長度的壓力鋼管進行模擬，並將電路等值方法和特徵線方法比較。
In this article the procedures are de-scribed for determining free-vortex segment properties.Characteristics method is used to design nozzle Milch produces free-vortex seg-ment. 本文提出了確定氣動窗口所需自由旋渦氣動特性的過程，討論了特徵線方法在非對稱超音速噴管設計中的應用，該噴管被用來產生自由旋渦流動。
