Question

Gating design for a mould of 50cm*25cm*15cm is shown in below figure. The cross-sectional area of the gate is 5 cm^2. Neglecting friction and velocity distribution effects, what is the filling time (t) for the design (in second)?

(a) 19.25

(b) 21.86

(c) 34.21

(d) 10.39

This question was addressed to me in an international level competition.

Enquiry is from Effects of Friction and Velocity Distribution topic in portion Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Correct choice is (b) 21.86

Easy explanation: H (Total height) = 15 cm, from the figure.

v (Velocity of molten metal) = √2gH = √2*981*15 cm/sec = 171.6 cm/sec.

V (Volume of the mould) = 50*25*15 cm³ and A (Cross-sectional area of the gate) = 5 cm^2.

As we know, t = V/Av

So, t (Filling time) = 50*25*15/5*171.6 sec = 21.86 sec.