IMPROVED PROPORTIONAL V-NOTCH WEIRS.

This paper is concerned with an improved design of proportional V-notch weirs incorporating two additional features, viz, (i) Equal slope at the junction of the base weir and the complimentary weir, and (ii) Constant indication accuracy. In first two designs, these features have been incorporated independently by taking the bases in the form of y//1 equals C//1 plus C//2x//1**3**/**2 and y//1 equals C//1 plus C//2x//1**2. It has been shown that, with the above bases, it is not possible to obtain these features simultaneously, whereas it has been obtained in a third design having the base in the form of y//1 equals C//1 plus C//2x//1**3**/**2 plus C//3x//1**2. The analysis has been done using the slope-discharge continuity theorem. The problem is soved as a solution of Volterra's integral equation in the Abel's form. Experiments with the weir of third design show excellent agreement with the theory by giving a constant average coefficient of discharge of 0. 60.