92 



HYDRAULICS AND ITS APPLICATIONS 



96 per cent, (in circular pipes) of the minimum possible loss in a 

 uniformly tapering pipe undergoing the full enlargement section. By 

 designing the pipe 

 from AI to A 3 with 

 curved boundaries, the 

 loss may be still further 

 reduced. In the 

 majority oi cases 

 occurring in practice, 

 however, the addi- 

 tional trouble of cal- 

 culation and cost of 

 template will not be 

 counterbalanced by 

 the slight increase in efficiency which they render possible. 



Effect of projecting Smaller Pipe into Space bounded by Diverging Walls. 

 For the purpose of examining this effect, a thin sleeve of internal 

 diameter "90 inch and external diameter 1*0 inch was prepared and used 

 inside the various 1-inch pipes, as shown in Fig. 44. 



The results of the experiments are as follow : 



FIG. 44. 



Percentage Loss of Head. 



In every case the effect of the projection is to increase the loss, the 

 effect being greater the greater the length of the projection and also the 

 less the angle of divergence of the conical sides. The loss is, in fact, 

 greater in every case than would be experienced if the pipe walls were 

 tapered off from the extremity of the projecting pipe, as shown by the 

 dotted lines in the sketch 



