Derive an expression and determine the present uncertainty in the Nusselt number value for Natural convection heat transfer between the stored water in the enclosure and the water flowing through a single tube heat exchanger located at the top of the inclined enclosure. The boundary conditions are shown in the Figure. Take: Pwater-998kg/m m=0.15kg/s, Cp=4.17kj/kg.K, K=0.623w/m.C, D=10mm, Twater,stored=45C, Thot =53C Tw.in=25C, Tw.out=46C, W=80cm, L=100cm, B=11cm Hot water out Insulated wall L Stored water W cold water in Insulated wall Insulated Wall Hot Wall