6.1.3 Resistance

What does the resistance include? How to achieve resistance ratio in the previous equation () will be discussed herein further. The total resistence reads = 0.4

Figure: y connection

(6.12)

The contraction resistence, , is the due the contraction of the gate. The exit resistence, , is due to resitence of the liquid metal in mold cavity. Or in other words, the exit resistence is due the lost of energy of emersed jet. The angle resistence, is due to the change of direction. The is the resistence due to flow in the branch on branch . The geometry resistence , is due to who rounded the connection.

(6.13)

since

(6.14)

(6.15)

Lets assume further that ,

(6.16)

(6.17)

(6.18)

Comparison between scrap between (multi-lines) two lines to one line

first find the diameter equalent to two lines

(6.19)

(6.20)

subtitling in to

(6.21)

Now we know the relationship between the hydraulic radius. Let see what is the scrap difference between them.

put drawing of the trapezoid

let scrap denoted by

converting the equation

(6.22)

the ratio of the scrap is

(6.23)

and now lets write in term of the two other

(6.24)