Osborne Reynolds Apparatus
The Osborne Reynolds Apparatus by Atto Labware is a classic experimental setup designed to demonstrate the nature of laminar, transitional, and turbulent flow in a pipe. By visualizing the flow pattern using dye injection, students can determine the critical Reynolds number and understand the transition between different flow regimes. It is an essential apparatus for Fluid Mechanics, Civil, and Mechanical Engineering laboratories.
Educational Objectives
Students and researchers will be able to:
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Observe and distinguish laminar, transitional, and turbulent flow regimes.
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Determine the critical Reynolds number experimentally.
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Understand the relationship between velocity, viscosity, and pipe diameter.
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Verify Reynolds’ law of similarity and flow transition.
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Relate theoretical predictions to observed flow patterns.
Performance Measurement
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Measurement of flow rate using a volumetric tank or rotameter.
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Observation of flow pattern using dye injection and transparent test pipe.
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Determination of Reynolds number using known parameters (velocity, viscosity, diameter).
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Comparison of observed transition point with theoretical value.
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Evaluation of effects of flow rate and temperature on flow behavior.
Panel and Instruments / Components
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Transparent Flow Tube: Long, clear acrylic tube for visual observation of flow.
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Dye Injection System: Dye reservoir and fine nozzle for uniform dye introduction.
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Flow Control Valve: Regulates water flow rate precisely.
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Feed Tank: Constant head tank to ensure steady flow.
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Measuring Tank: Graduated volumetric tank for discharge measurement.
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Stopwatch: For accurate time measurement during flow rate calculations.
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Drain and Return Line: For continuous water circulation.
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Support Frame: Powder-coated steel stand with anti-corrosive finish.
Specifications (Includes Technical Data)
| Feature | Detail |
|---|---|
| Test Tube Length | 800–1000 mm |
| Tube Diameter | 10–20 mm (clear acrylic) |
| Flow Range | 0.1 – 2 L/min |
| Dye Reservoir Capacity | 100 mL (with fine needle control) |
| Feed Tank Capacity | 40–50 L |
| Measuring Tank Capacity | 25 L |
| Power Supply | Not required (gravity-fed) |
| Working Fluid | Water with dye tracer |
| Construction | Transparent acrylic tube, stainless steel fittings |
| Dimensions | 1000 mm L × 500 mm W × 1000 mm H |
| Weight (Approx.) | 20 kg |
Note: Optional digital flow sensors and Reynolds number calculation software available on request.





