Question

In case of parallel pipes a the head loss for all the pipes is same b the total discharge is equal to the sum of discharges in the various pipes c the total head loss is the sum of head losses in the various pipes d both (1) and (2)

Answer 1

When two or more pipes are connected, as shown in Fig. 36.3, so that the flow divides and subsequently comes together again, the pipes are said to be in parallel.In this case (Fig. 36.3), equation of continuity gives(36.5)

where, Q is the total flow rate and  and  are the flow rates through pipes A and B respectively.

Loss of head between the locations 1 and 2 can be expressed by applying Bernoulli's equation either through the path 1-A-2 or 1-B-2. 
Therefore, we can write



Fig 36.3 Pipes in Parallel

     

 

and     

 

Equating the above two expressions, we get -

          

(36.6)
where,   
           

Equations (36.5) and (36.6) give -

(36.7)

where,    

(36.8)The flow system can be described by an equivalent electrical circuit as shown in Fig. 36.4.