The GATE Grind

GATE 2017 ME (ME1) – Question 64

Casting, Forming and Joining Processes · Plastic deformation and yield criteria, hot and cold working · 2 marks · Numerical answer

A sand-mould sprue has top diameter 20 mm and height 200 mm. Molten metal enters at 0.5 m/s. The mould is well ventilated; take g = 9.8 m/s² and neglect losses. Find metal speed at the sprue bottom in m/s, to three decimal places.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 2.04 to 2.07

Explanation

Top and bottom are at atmospheric pressure under the stated ventilation assumption. Bernoulli’s equation gives $v_b^2=v_t^2+2gh=0.5^2+2(9.8)(0.2)=4.17$. Thus $v_b=\sqrt{4.17}=2.04206$ m/s, or 2.042 m/s. The top diameter determines flow rate but cancels from this lossless energy relation.

More Plastic deformation and yield criteria, hot and cold working questions

All Plastic deformation and yield criteria, hot and cold working questions →