Question

Question 2 (2. (8 marks) 1) What is the criterion required for a. the applicability of the lumped capacitance method? b. the applicability of the one-term approximation to the series solutions for transient 1-D conduction in a plane wall? a plane wall of thickness 2L to be approximated as a semi-infinite solid? c. (2.2) A very thick black-painted wood block (k 0.16 W/m K and a 1.8 x 10 m2/s) at 20°C is subjected to constant solar heat flux of 500 W/m Determine the exposed surface temperature of the block after 20 minutes. were made of alun W/m-K and '_ 9.7 x10-5 m2/s)? (2.4) Compare and discuss the results in (2.2) and (2.3).

Answer 1

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