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SECTION 2: TRAPEZOIDAL AND CIRCULAR CHANNEL ANALYSIS PROGRAMS <br /> 2.4.4 Examples of Normal Depth Procedure <br /> 2.4.4.1 Computing Normal Depth in a Trapezoidal Channel <br /> 2.4.4.1.1 Description of Example for Trapezoidal Channel <br /> Example 6-4 of Chow's "Open Channel Hydraulics" (Chow 1959) relates to the <br /> computation of Normal Depth in a trapezoidal channel. The channel in the <br /> example has a bottom width of 20 feet, side slopes of 2:1, a Manning's <br /> roughness coefficient of 0.025, and a required flow capacity of 400 cfs. <br /> 2.4.4.1.2 Solution of Example for Trapezoidal Channel <br /> Chow's manual computations indicate that the Normal Depth of flow in the <br /> channel under the stated conditions is 3.36 feet. As indicated by the example <br /> screen display, the Trapezoidal Channel Analysis program provides exactly the <br /> same result. The computed flow velocity also agrees very well with the value <br /> computed by Chow. Chow computed a flow velocity of 4.46 fps, whereas the <br /> program computes a value of 4.45 fps. <br /> 2.4.4.1.3 Example Screen Display for Trapezoidal Channel <br /> TRAPEZOIDAL CHANNEL ANALYSIS <br /> Normal Depth COMPUTATION <br /> Flow Rate (cubic feet per second) 400 <br /> Channel Bottom Slope (feet per foot) .0016 <br /> Manning's Roughness Coefficient (n-value) .025 <br /> Channel Side Slope - Left Side (horizontal/vertical) 2 <br /> Channel Side Slope - Right Side (horizontal/vertical) 2 <br /> Channel Bottom Width (feet) 20 <br /> *** RESULTS *** <br /> Normal Depth (FEET) 3.36 <br /> Flow Velocity (feet per second) 4.45 <br /> Froude Number .479 <br /> Velocity Head (feet) .31 <br /> Energy Head (feet) 3.67 <br /> Cross-Sectional Area of Flow (square feet) 89.83 <br /> Top Width of Flow (feet) 33.45 <br /> [Press Enter key to repeat, R to Print Report, or Esc to return to Main Menu <br /> 2.4.4.2 Computing Normal Depth in a Circular Channel <br /> 2.4.4.2.1 Description of Example for Circular Channel <br /> As an example of the Normal Depth procedure for a circular channel, assume that <br /> a circular pipe culvert 8 feet in diameter connects two stormwater detention <br /> DODSON & ASSOCIATES, INC. THE DODSON HYDRAULICS LIBRARY, PAGE 19 <br />