Pelton Wheel — Recommended Bucket Depth For a Pelton wheel, the typical depth of a bucket is approximately how many times the jet diameter?

Mechanical Engineering Hydraulic Machines Difficulty: Easy
Choose an option
  • A
    equal to
  • B
    1.2 times
  • C
    1.8 times
  • D
    double

Answer

Correct Answer: 1.2 times

Explanation

Introduction:Geometric proportions of Pelton buckets (width, depth, splitter dimensions) are standardized to capture and deflect the jet effectively while minimizing losses and avoiding jet interference.

Given Data / Assumptions:

  • Impulse turbine with free jet striking double-cupped buckets.
  • Design guidance from classical proportions used in practice.

Concept / Approach:Bucket depth affects jet containment and deflection angle. Too shallow causes spillage; too deep increases friction and weight. Empirical design ratios recommend bucket depth about 1.2 * d, where d is jet diameter, balancing capture and hydraulic efficiency.

Step-by-Step Solution:Choose bucket dimensions based on jet size.Adopt depth ≈ 1.2 * d to house the jet adequately.Verify clearance to avoid interference with adjacent buckets.

Verification / Alternative check:Reference proportion sets also suggest bucket width ≈ 5 * d and pitch ≈ 2.3 * d, consistent with the chosen depth.

Why Other Options Are Wrong:equal to: marginal capture; prone to spillage.1.8 times and double: unnecessarily deep, increasing losses and mass.

Common Pitfalls:Using nonstandard ratios that degrade hydraulic efficiency.

Final Answer:1.2 times

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