online_wsprofiles_32: H2 water-surface profile
- The php script [program] online_wsprofiles_32
calculates an H2 water-surface profile in a prismatic open channel using the direct-step method (Chow, V. T.: Open-channel hydraulics, McGraw-Hill, 1959).
- If requested by the user, the program calculates critical depth at the downstream boundary [default value]
based on the geometric and hydraulic input data. Newton's iteration is used to solve the nonlinear equations.
- An H2 profile is supernormal, subcritical, and the bottom slope is horizontal (see figure).
The calculated gradually varied flow depth varies between the specified flow depth
at the downstream boundary [or, if requested, the calculated critical depth] and the specified flow depth upstream [headwater depth].
- There are four required input variables: discharge Q, bottom width B, side slope z, and Manning's n.
- For the downstream boundary condition, you can specify a suitable input flow depth.
Alternatively, if the input flow depth box is left blank,
the program will use critical depth instead.
- For the upstream boundary condition, you must specify a suitable upstream flow depth [headwater depth].
- By convention, the flow direction is assumed to be from left to right, as shown in the figure. Therefore,
the input upstream flow depth must be greater than the input [or calculated critical] downstream flow depth.
- The program echoes the input data. Internally calculated critical depth is echoed with five-decimal (5) accuracy.
- For the input flow depth, you can enter
any suitable subcritical supernormal flow depth.
The allowable range of input flow depth is the following: Greater than [or equal to] critical depth, and less than [input] upstream flow depth.
Leave this box blank if you want the program to use critical depth.
- You can enter the desired number of computational intervals n. The suggested range is 50-200. A higher number
means higher computational accuracy.
Leave this box blank if you want the program to set the default value at 100.
- You can enter the desired number of tabular output intervals m. The suggested range is 10-100. A higher number
means more detailed [longer] output.
Leave this box blank if you want the program to set the default value at 10.
- A table with thirteen (13) columns: output interval index k, [flow] depth (m),
[flow] area (m2), velocity (m/s), velocity head (m), specific head (m), wetted perimeter (m), hydraulic radius (m),
friction slope (m/m), average [friction] slope (m/m), specific head difference (m), length increment (m), and total [channel] length (m).
- The number of computational intervals n and the number of tabular output intervals m are printed for reference.
- The current version is written in SI [metric] units.
- Enter only positive [nonzero] numbers for discharge.
Failure to do this will trigger an error message and halt execution (Error message No. 1).
- Enter only nonnegative [zero or greater] numbers for bottom width and side slope.
Failure to do this will trigger an error message and halt execution (Error messages No. 2: A and B, respectively).
- Bottom width and side slope cannot be zero at the same time.
Failure to do this will trigger an error message and halt execution (Error message No. 3).
- A Manning's n value outside of the range 0.008-0.250
will trigger an error message and halt execution (Error message No. 4).
- An input downstream flow depth less than the calculated critical depth
will trigger an error message and halt execution (Error message No. 5).
- An input downstream flow depth greater than or equal to the input upstream flow depth [minus a tolerance of 0.001 m]
will trigger an error message and halt execution (Error message No. 6).
- An input upstream flow depth less than or equal to the input (or calculated) downstream flow depth [plus a tolerance of 0.001 m]
will trigger an error message and halt execution (Error message No. 7).
Thank you for running online_wsprofiles_32. Please call again. [Version 1.0.0, 070509]