Question: 1. A flat ribbon heat strip is oriented vertically on an insulating substrate. Let the ribbon be 1 m wide by 3 m long. Its energy dissipation is 0.5 W/cm2 to air at 25°C. What are the average heat-transfer coefficient and surface temperature of the ribbon? Where will transition to turbulent flow occur? Would you be justified in neglecting the laminar contribution to the heat transfer?
2. Using the approximate integral solution method for turbulent free function over a vertical and constant-temperature surface, develop an equation for J/x. Compare and discuss how the boundary-layer thickness varies with x for laminar and turbulent free and forced convection.