Laboratory Tilting Hydraulics Flume with Variable Jacks
8.0 m long by 0.30 m wide flume equipped with motorized screw jack slope adjustment (0% to 3.5%).
Civil Engineering / Manning Roughness Flume
FREE TO EXPLORELABORATORY 30 · CIVIL ENGINEERING
Manning Roughness Coefficient Determination in an Open Tilting Flume (Uniform Flow)
Determine Manning's roughness coefficient (n) and Chezy's coefficient (C) for smooth and artificially roughened open channels under steady uniform flow conditions across variable bed slopes. Explore interactive structural mechanics, materials simulation, and civil engineering telemetry.
STRUCTURAL MATERIALS · MECHANICS · GEOTECHNICAL · HYDRAULICS · HIGHWAYS · SURVEYING
Your virtual civil engineering laboratory.
MEAN FLOW VELOCITY V—
CIVIL INFRASTRUCTURE TELEMETRY
Ready to sample with Hydraulic Parameter = 0.02 m^(2/3).
Adjust Hydraulic Parameter, then execute civil engineering measurement.
Civil engineering telemetry is evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity structural mechanics and geotechnical continuum modeling.
Civil engineering assumptions and boundary condition limits
The civil engineering physical models apply within the specified calibrated operational window (0.01 to 0.035 m^(2/3)). Evaluated on smooth finished concrete flume bed (n = 0.0150 s/m^(1/3)). Linear regression correlates mean velocity v directly to hydraulic parameter R^(2/3)·S^(1/2) with slope 66.6667 m^(1/3)/s.
Laboratory apparatus & testing equipment.
Precision Digital Flume Inclinometer
Directly measures channel longitudinal bed slope S to 0.0001 precision (0.01 mm/m).
Vernier Depth Gauge Traversal Carriage
Monitors water surface elevation along flume centerline to confirm steady uniform flow (dy/dx = 0).
Electromagnetic Induction Flowmeter
Measures volumetric discharge Q with high precision (0.01 L/s resolution).
Miniature Acoustic Doppler Velocimeter (ADV)
Records point velocities across channel cross section to verify mean velocity v.
Adjustable Flume Tailwater Control Sluice
Trims downstream boundary depth to establish normal depth y_0 without drawdown or backwater.
FOLLOW THE METHOD
A reason behind every step.
Determine Manning's roughness coefficient (n) and Chezy's coefficient (C) for smooth and artificially roughened open channels under steady uniform flow conditions across variable bed slopes. Standardized parameter settings: 0.01, 0.015, 0.02, 0.025, 0.03, 0.035 m^(2/3).
01
Flume Bed Slope Setting & Datum Calibration
Adjust motorized flume jacks to target longitudinal bed slope S; verify slope with digital inclinometer; zero vernier depth gauges to flume bed.
02
Uniform Flow Establishment
Start recirculation pump; adjust discharge Q and tailwater gate until water surface is parallel to channel bed (constant depth y_0 at all stations).
03
Normal Depth & Cross-Sectional Geometry Logging
Measure normal depth y_0; compute wetted area A = B · y_0, wetted perimeter P = B + 2y_0, and hydraulic radius R = A / P.
04
Discharge & Mean Velocity Determination
Record steady discharge Q; compute cross-sectional mean velocity v = Q / A; calculate hydraulic parameter R^(2/3) · S^(1/2).
05
Systematic Slope and Flow Variation
Repeat procedure across six systematic hydraulic parameter levels (0.010, 0.015, 0.020, 0.025, 0.030, and 0.035 m^2/3).
06
Manning n & Chezy C Regression Computation
Plot v versus R^(2/3) · S^(1/2); determine linear slope 1/n; calculate Manning's n = 1 / slope; determine equivalent Chezy coefficient C = R^(1/6) / n.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into civil engineering insight.
Points are your recorded observations. The solid regression line validates Manning Roughness Flume mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
v = 66.6667 · [R^(2/3)·S^(1/2)] (n = 0.015 s/m^(1/3))
| # | Hydraulic Geometry Parameter R^(2/3)·S^(1/2) (m^(2/3)) | Mean Flow Velocity v (m/s) | Hydraulic geometry parameter R^(2/3)·S^(1/2) (m^2/3) | Mean cross-sectional velocity v (m/s) | Remove |
|---|
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CHECK YOUR UNDERSTANDING
Explain what the civil engineering metrics mean.
In the SI version of the Manning equation (v = (1/n) · R^(2/3) · S^(1/2)), the units of Manning's n are:
For a rectangular channel of width B and depth y, the hydraulic radius R is given by:
Under steady uniform flow conditions in an open channel:
A typical Manning roughness coefficient n for smooth, finished concrete canal lining is approximately:
THEORY AND STRUCTURAL CONTEXT
Civil engineering background & physical principles.
In open channel hydraulic design—governing storm drainage canals, aqueducts, river floodways, and natural waterways—the resistance to gravity-driven steady uniform flow is parameterized by empirical friction coefficients. Formulated by Irish engineer Robert Manning in 1889, the Manning equation expresses mean flow velocity as v = (1/n) · R^(2/3) · S^(1/2), where v is mean cross-sectional velocity (m/s), n is Manning's roughness coefficient (s/m^(1/3)), R = A / P is hydraulic radius (wetted flow area A divided by wetted perimeter P), and S is channel bed slope (equal to energy slope S_f in steady uniform flow). Manning's n embodies surface roughness of channel boundaries, form resistance from sand ripples or dunes, vegetation drag, and channel planform sinuosity. Smooth painted steel or planed timber exhibits n ≈ 0.010 to 0.012 s/m^(1/3); smooth troweled concrete has n ≈ 0.013 to 0.015 s/m^(1/3); gravel-bed mountain streams range from n = 0.030 to 0.050 s/m^(1/3); and heavily vegetated floodplains exceed n = 0.080 s/m^(1/3). In this laboratory flume experiment, uniform flow depth y_0 is maintained across varying bed slopes S and discharges Q. Plotting mean velocity v against the compound hydraulic geometric parameter R^(2/3) · S^(1/2) directly yields the reciprocal of Manning's roughness coefficient (1/n), enabling precise verification of concrete flume boundary resistance.
v = 66.6667 · [R^(2/3)·S^(1/2)] (n = 0.015 s/m^(1/3))
Evaluated on smooth finished concrete flume bed (n = 0.0150 s/m^(1/3)). Linear regression correlates mean velocity v directly to hydraulic parameter R^(2/3)·S^(1/2) with slope 66.6667 m^(1/3)/s.