Project ForgeConsider a two-dimensional laminar flow over a long cylinder, with free stream velocity U∞ and free stream temperature T∞ lower than the cylinder surface temperature Ts. Four points are marked around the cylinder circumference: point 1 at the front (upstream-facing) side, point 2 near the top, point 3 slightly past the top, and point 4 further round toward the rear where boundary-layer separation occurs. The local heat transfer coefficient is minimum at point
- A1
- 2
- C3
- D4
Explanation
For laminar cross-flow over a cylinder, the local heat transfer coefficient is highest at the front stagnation point (thinnest boundary layer) and falls as the laminar boundary layer thickens around the cylinder, reaching a minimum just before separation — typically near the top of the cylinder (around 80-100° from the front stagnation point) — before rising again in the turbulent wake region further downstream.
Source: GATE ME 2014 (Session 1 / Set-1) (2014)
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