🔍 Key Concepts

• Gas turbine blade geometry: root, midspan, tip, and chord definitions • What physically happens during tip clang (blade-to-casing contact) • Where impact and rubbing forces are concentrated when a rotating blade strikes a stationary surface

💭 Think About

• Visualize a turbine blade from hub to outer radius and imagine which portion touches the casing if the rotor grows or shifts • Ask yourself: in tip clang, which specific part of the blade actually hits or rubs against the stationary casing or shroud? • Consider which blade region is designed mainly for attachment versus which region is exposed to the smallest radial clearance

✅ Before You Answer

• Be clear on the difference between root (attachment at the hub) and tip (outermost radial edge) • Remember what midspan represents (the middle of the airfoil height, between root and tip) • Understand that chord is the front‑to‑back width of the blade at a given height, not a specific radial location like root, midspan, or tip