THEORY OF TURBINE DESIGN 



553 



cutting off equal areas r 2 di, Ci d, etc., from the triangle. Circles drawn 

 through ci, c 2 , etc., will now, by their intersections with the equidistant 

 vanes, give points on the path V in' of a particle. 



These curves may be utilized to obtain the absolute velocity of the 

 water and the relative velocity of water and vane at any radius, for 

 if at any point P of radius r, P q be drawn perpendicular to P and 

 equal to w r, and if q k be drawn parallel to the tangent to the vane at 











FlG. 259. Sketch showing actual path of particles of water through an Inward 

 Radial Flow Turbine. 



P and P k be drawn tangential to the curve at P, then since the actual 

 velocity of the particle at P is compounded of the velocity of the vane at 

 P, i.e., of co r, and of its velocity relative to the vane, and since its actual 

 velocity is tangential to the curve at P and its relative velocity is parallel 

 to the vane, P q k serves as the triangle of velocities at P, and P k = 



