Flow measurement structures – definition of a Venturi flume A Venturi flume is a specially shaped, flumed structure constructed across an open channel by restricting its width to measure discharge. Is this statement correct?

Introduction / Context:Venturi flumes (e.g., Parshall flumes) are widely used for open-channel flow measurement. They rely on a controlled contraction of the channel to create a known relationship between upstream head and discharge.

Given Data / Assumptions:

• Open-channel flow under gravity.
• Flume geometry includes converging, throat, and diverging sections.
• Adequate approach conditions and submergence limits are respected.

Concept / Approach:The narrowing (fluming) raises velocity and changes specific energy, establishing a head–discharge rating. Proper geometry ensures critical or near-critical conditions in the throat, making the discharge largely a function of upstream head over a wide range of downstream levels.

Step-by-Step Reasoning:

Verification / Alternative check:Standard rating tables and empirical equations for Venturi/Parshall flumes confirm the definition: a constricted channel section used for discharge measurement.

Why Other Options Are Wrong:

• “False” contradicts field practice.
• Pipeline or weir requirements are irrelevant; flumes are independent structures for open channels.

Common Pitfalls:Confusing Venturi meters (for pipes) with Venturi flumes (for open channels). They share a principle but are used in different flow regimes.

Final Answer:True