Question

Friction loss factor (eғ) in the conduit of liquid metal depends on _____

(a) temperature of the molten metal

(b) presence of dross in the molten metal

(c) ratio of the flow area and Reynolds no. of the flow

(d) whirling of the molten metal

I had been asked this question by my school principal while I was bunking the class.

I'd like to ask this question from Effects of Friction and Velocity Distribution in portion Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Correct choice is (c) ratio of the flow area and Reynolds no. of the flow

Easiest explanation: eғ is the friction loss factor and it depends on the ratio of the flow area and Reynolds number of the flow. For a laminar flow, the length and diameter of the smaller flow cross-section have to be taken into account. The value of eғ depends on whether the flow area is enlarging or contracting in the direction of flow.