CORRECTION OF FORMULA. 



The reason for the difference between the computed and observed maximum 

 discharges lies in the fact that the curve for the observed discharge is not 

 a true sinusoidal curve as it was considered to be in the first assumption.. 

 Since the hydraulic flow through an inlet is due to turbulent forces, it is 

 expected that the true curve of the discharge has other harmonics. This is 

 known to be true since the simple sine curve used as the first assumption 

 applies only when the flow through an inlet is viscous. This can be shown 

 very easily, 



Suppose that a small reservoir is connected with a large reservoir 

 through a capillary connection. 



h, 



£ 



T~ 



MEAN WATER LEVEL 



~1 



FIGURE 2 



Let h]_ and h2 be the fluctuations of the surface elevations above and below 

 the mean water level in the small and large reservoirs respectively (figure 

 2)„ Inasmuch as the flow in this case is due to viscous forces the discharge 

 q is proportional to the difference , h2 - h^ 3 that is! 



where 



in which 



q= a(h 2 -hj ) 



(6) 



r = the radius of the capillary tube 



fj. = the viscosity of the fluid 



t = the length of the capillary tube 



p = the density of the fluid 



Letting the surface area of the small reservoir equal A 



dh. 



q= A 



df 



Equating the right hand members of equations 6 and 7 



dh, 

 dT 



Att- =a(h 2 -h,) 



This equation may be written 



dh, 



— = Ch 2 -Ch, 



18 



(7) 

 (8) 

 C9) 



