Definition
A turbine wheel design in which the blades (called buckets) are attached around the rim of a disk, with the working fluid -- exhaust gas, steam, or air -- striking the curved bucket faces to spin the wheel. In aviation, bucket wheels are found in turbochargers, turbine engines, and air-driven starters, where the shape of each bucket captures the energy of the moving gas and converts it into rotational force.
Plain English
A spinning wheel with cup-shaped blades around its edge. Hot gas or air pushes against the cups and makes the wheel turn.
Context Anchor
Seen in aircraft engine and turbocharger discussions, especially when describing how exhaust flow is used to spin engine components.
Derivation
Called a 'bucket' wheel because each blade is shaped like a small scoop or cup that catches the moving gas, much like a waterwheel's paddles catch flowing water. The shape is what does the work.
Why Pilots Care
The condition of bucket wheels directly affects engine performance. Damaged, eroded, or contaminated buckets reduce turbine efficiency, which shows up as lower power, higher operating temperatures, or slower spool-up.
Analogy
Think of an old waterwheel: cupped paddles catch the flow and turn the wheel. A bucket wheel does the same thing with hot gas instead of water.
Intuition Check
Do not picture a wheel carrying actual buckets. In this term, the “buckets” are the curved blades that the gas pushes against.
Example Sentence 1
During inspection, the mechanic checked the turbocharger's bucket wheel for cracks and erosion from prolonged high-temperature operation.
Example Sentence 2
A cracked bucket wheel reduces turbine efficiency and can lead to compressor surge.