The volume flow rate of metal into a mold is .025m^3/min. The top of the sprue has a diameter of 20mm and its length is 200mm. Recall, g=9.81m/s^2.
Assume no frictional losses and recognize that the pressure at the top and bottom of the sprue is atmospheric.
Assume to prevent aspiration, the sprue opening should be such that it is the same required by flow continuity.
(A) What diameter should be specified at the bottom of the sprue to prevent aspiration?
(B) What is the resultant velocity and Reynolds number at the bottom of the sprue is the metal being cast is aluminum with viscosity of .004Ns/m^2 and density of 2700kg/m^3. From the Reynolds number, describe the flow of the metal in terms of laminar/turbulent flow.