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Francis Formula Rectangular Weir Calculator

Calculate discharge over rectangular suppressed and contracted thin-plate weirs with Francis formula.

Calculated Result
1.3886 m³/s

Discharge

Flow Rate in L/s

1388.6 L/s

Flow Rate in cfs

49.04 cfs

Effective Length

2.5 m

Calculation Breakdown

  1. Francis Suppressed FormulaQ = 1.84 · (L - 0.1·n·H) · H^(3/2) => 1.3886 m³/s

Weir Discharge

Interactive visualization based on your current inputs

Value
0.00.30.71.01.4Discharge (m³/s)Head (m)MetricValue

What Is the Francis Formula Rectangular Weir Calculator?

Calculate discharge over rectangular suppressed and contracted thin-plate weirs with Francis formula.

The Francis Formula Rectangular Weir Calculator is an analytical tool in the construction domain designed to evaluate Crest Length (L), Head (H) using verified mathematical equations. It provides reproducible, deterministic calculations for academic, professional, and practical applications.

How Does the Francis Formula Rectangular Weir Calculator Work?

This calculator computes results by taking input values for Crest Length (L), Head (H) and applying the governing equation: Francis formula for rectangular weirs.. Values are checked for dimensional consistency and processed through standard arithmetic routines.

Francis Formula Rectangular Weir Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

Q=1.84(L−0.1nH)H3/2Q = 1.84 (L - 0.1 n H) H^{3/2}

Francis formula for rectangular weirs.

How to Use the Francis Formula Rectangular Weir Calculator

  1. Enter your value for Crest Length (L) in m.
  2. Enter your value for Head (H) in m.
  3. Verify your input parameters to ensure they match your design or problem specifications.
  4. Review the calculated results, intermediate mathematical steps, and graphical visualization below.

Step-by-Step Example Calculation

Weir Flume

Input Values:

crestLengthM:2.5
headOverCrestM:0.45
Worked Steps: Computed using the primary formula for Francis Formula Rectangular Weir Calculator with the sample input parameters shown above.

Understanding Your Result

The calculated output gives the primary solution for Francis Formula Rectangular Weir under the specified conditions. Use this value to compare against standard design tolerances, benchmarks, or reference ranges in construction.

Factors That Affect the Result

  • Input precision and measurement accuracy of Crest Length (L), Head (H).
  • Operating conditions, environmental parameters, and specific construction tolerances.
  • Boundary constraints and deviations from nominal theoretical model assumptions.

When Should You Use This Calculator?

  • When performing technical analysis or dimensioning related to Francis Formula Rectangular Weir.
  • To cross-verify manual calculations or theoretical models in construction.
  • For preliminary estimates before conducting detailed field measurements or laboratory testing.

Assumptions & Limitations

  • For suppressed weirs, end contractions n = 0.

Frequently Asked Questions

What is a suppressed weir?+
A weir matching channel width with no side contractions.

Calculation Accuracy & Reference Note

This calculator implements verified mathematical formulas for Francis Formula Rectangular Weir Calculator. Always verify critical results against official domain standards and manufacturer documentation.

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