Question

Molten metal can be poured into the pouring cup of a sand mold at a steady rate of 1000 cubic centimeter per second. The molten metal overflows the pouring cup and flows into the downsprue. The cross-section of the sprue is round, with a diameter at the top = 3.4 cm. If the sprue is 25 cm long, determine the proper diameter at its base so as to maintain the same volume flow rate.

Answer 1

sorry to say I do not know

Answer 2

Explanation:

Velocity at base v=(2gh)^{ 0.5 }=(2v=(2gh)

0.5

=(2x981981x25)^{ 0.5 }=221.5cm/s25)

0.5

=221.5cm/s

Assuming volumetric continuity, area at base A=(1000cm/s)/(221.5cm/s)=4.51cm^{ 2 }A=(1000cm/s)/(221.5cm/s)=4.51cm

2

Area of sprue A=πD^{ 2 }/4;A=πD

2

/4; rearranging,D^{ 2 }=4A/π=4(4.51)/π=5.74cm^{ 2 }D

2

=4A/π=4(4.51)/π=5.74cm

2

D = 2.39 cmD=2.39cm