What are the characteristics of a critical flow Is critical

What are the characteristics of a critical flow? Is critical flow a desirable or undesirable flow condition? Justify your answer.

Solution

The characteristics of critical flow are
(i) The specific energy and specific force are minimum for the given discharge.
(ii) The Froude number is equal to unity.
(iii) For a given specific energy the discharge is maximum at the critical flow.
(iv) The velocity head is equal to half the hydraulic depth in a channel of small slope.

Critical, or choked, flow is a compressible flow effect. it is also desirable flow...