Consider flow over a flat plate for which it is desired to determine the average heat transfer coefficient over the short span x1 to x2, h1 – 2 where (x2 – x1)

Provide three different expressions that can be used to evaluate hl - 2 in terms of

(a) The local coefficient at x = (x1 + x2)/2,

(b) The local coefficients at XI and X b and

(c) The average coefficients at x1 and x2 Indicate which of the expressions is approximate. Considering whether the flow is laminar, turbulent, or mixed, indicate when it is appropriate or inappropriate to use each of the equations.

T, Lot X1 *2 11