In free convection heat transfer, Nusselt number is function of А. Grashoff number and Reynold number В. Grashoff number and Prandtl number C. O Prandtl number and Reynold number D. O Grashoff number, Prandtl number and Reynold number

This is a multiple part question and i need help with only part D, part D might need some help from above parts that is provided in the table and the equations avaliable.

2-D: A fin may be manufactured as an integral part of a surface by using a casting or extrusion process, or it may be separately brazed or adhered to the surface. From thermal considerations, which option is preferred? 2-E: What is the difference between steady-state and transient heat transfer processes? Give an example for each of them. 2-F: What is the physical interpretation of the Biot number? 2-G: For flow over a flat plate, sketch variation of local convective heat transfer coefficient, h(x), versus the distance along the plate x for laminar, transition, and turbulent flow regimes.

Parvinbhai

Steel cubes 10 mm in width are annealed by heating to 1,377 K and then slowly cooling to 469 K in an air environment for which T∞ = 301 K and h = 24 W/m2-K. Assuming the properties of the steel to be k = 24 W/m · K, ρ = 7,047 kg/m3, and c = 916 J/kg · K, estimate the time required for the cooling process.