Consider laminar fluid flow through a circular tube with a condition of uniform heating at the sur- face of the tube (uniform surface heat flux condition). (a) Show that NuD (Nusselt number with respect to tube diameter, D) is constant for thermally fully developed condition in the tube. (b) Sketch how the convective heat transfer coefficient varies along flow direction (x), and physically explain the reason for such variation. This problem is NOT limited to thermally fully developed condition only. You will have to include both entry and fully developed re- gions (x > 0). (c) Plot how average temperature (Tm) and wall surface temperature (Ts) vary along flow direc- tion (x-direction). This problem is NOT limited to thermally fully developed condition only. You will have to include both entry and fully developed regions (x≥ 0). (d) Now assume that a liquid metal is flowing inside the tube. Under this situation, we can effectively assume that the velocity profile is uniform; u(r) : temperature profile and Nup. = Um = constant. Calculate the