00:01
Here we will first write the head loss equation.
00:05
By bernoulli equation we can write the head loss equation.
00:07
So it will be p1 divided by row plus alpha 1 multiplied by v1 squared divided by 2 plus gz1 minus p2 divided by row plus v2 plus alpha 2 multiplied by v2 plus gz2 plus gz2 is equal to head loss due to friction which can be written as f l v f l v square f l v2 square divided by 2d plus head loss due to head loss due to sudden contraction which can be written as kv square kv2 squared divided by 2 here since the 5 is horizontal so we can write we can write z1 is equal to z2 also let us assume the kinetic kinetic kinetic kinetic energy correction factor is equal to 1 so alpha 1 will be equal to alpha 2 alpha 1 will be alpha 2 so we can write we can write from above equation v1 squared divided by 2 plus g z 1 gz 1 minus v2 squared divided by 2 is equal to kv2 square divided by 2 let this is equation number 2 and this is equation number 1 this is equation number 1 now from the now since the flow is re -interrant type, hence from the table of minor loss coefficient for the pipe entrance, we can write k is equal to 0 .78.
01:44
Also, also, from continuity equation, we can write a1 v1 is equal to a2 v2, hence the velocity v1 will be equals to v2 multiplied by a2 divided.
02:00
By a 1 a 2 divided by a 1 now from equation 2 from equation 2 we can write we can write v2 square v2 divided by 2 multiplied by a 2 divided by a 1 whole square whole square plus g z 1 is equal to minus minus v2 squared divided by 2 is equal to kv2 squared divided by 2 so from here we can write v2 square is equal to 2 g z1 divided by 1 plus k minus a 2 by a 1 whole square so we will put all the values and we will get 2 multiplied by 9 .81 1 multiplied by 0m .8 is 1 meter divided by 1 plus the value of k is 0 .78 minus a 2 is 350 and a 1 is 3 ,500 this is square so from here we get the value v2 is equal to 3 .3 meter per second hence discharge q can be written as a2 multiplied by v2 a2 is given as 350 multiplied by 10 to the power of minus 6 multiplied by 3 .33 3 .33 so it will come out to be 1 .1 1 .17 multiplied by 10 to the power of minus 3 meter cube per second minus 3 meter cube per second so so so if if a large flow rate is required if q to be large to be large then then the outlet area then the outlet area or the outlet pipe diameter a2, a2 must be increased.
04:10
A2 has to be increased.
04:15
Has to be increased...