Chapt10

1030 as q2 3 gyc gycy2 c v2y2 c c 1032 by comparison

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: is impossible physically. For E Emin two solutions are possible: (1) large depth with V Vc, called subcritical, and (2) small depth with V Vc, called supercritical. In subcritical flow, disturbances can propagate upstream because wave speed C0 V. In supercritical flow, waves are swept downstream: Upstream is a zone of silence, and a small obstruction in the flow will create a wedge-shaped wave exactly analogous to the Mach waves in y Constant q Horizontal hf y=E EGL E v v Subcritical yc Fig. 10.8 Specific-energy considerations: (a) illustration sketch; (b) depth versus E from Eq. (10.29), showing minimum specific energy occurring at critical depth. | V2 2g Critical y Supercritical 0 (b) (a) | e-Text Main Menu E E min | Textbook Table of Contents | Study Guide 10.4 Specific Energy; Critical Depth 673 Fig. 9.18c.2 The angle of these waves must be 1 sin c0 V 1 sin (gy)1/2 V (10.34) The wave angle and the depth can thus be used as a simple measurement of supercritical-flow velocity. Note from Fig. 10.8b that small changes in E...
View Full Document

This note was uploaded on 10/27/2009 for the course MAE 101a taught by Professor Sakar during the Spring '08 term at UCSD.

Ask a homework question - tutors are online