🔍 Key Concepts
• Review what a diffuser does in a centrifugal/axial flow device (what happens to velocity and pressure).
• Notice which numbered part forms the stationary passage immediately after the rotating wheel/blades where flow slows down and pressure increases.
• Compare shapes: a diffuser is usually a gradually widening, fixed passage rather than a thin ring, shaft, or control valve.
💭 Think About
• Which numbered component is directly in line with the exiting flow from the rotating blades and provides space for that flow to slow down and spread out?
• Looking at each option (1, 3, 9, 7), which ones are moving parts or controls, and which one is a stationary flow passage with a flared shape?
• For each candidate number, ask: does this part guide the main gas/air stream outward and convert high velocity to higher pressure, or does it mainly support, seal, or control something?
✅ Before You Answer
• Be sure the part you pick is fixed (non‑rotating) and surrounds or follows the rotor/impeller where the arrows show the main flow path.
• Confirm that its geometry is wider at the outlet than the inlet, consistent with a diffuser passage.
• Verify you are not choosing a valve, shaft, or small fitting; the diffuser is a larger flow-shaping component.