Closure to “Discussions of ‘A Better Method of Representing and Studying Water-Turbine Performance’” (1946, Trans. ASME, 68, pp. 682–684)

Abstract

FIG. 8 REGULATION CONSTANT AVAILABLE FOR NORMAL WW OF GENERATORS the water column to that of the unit, when instability occurred, was about 0.2. This ratio is obviously not the only factor involved, but is believed to be an important one, and the author suspects, from a study of other plants, that not a few units which now operate very sweetly on the line would be unstable if supplying a rheostat load. The problem is analogous to but more complicated than the stability of surge tanks; and the author wishes at this time to bring the phenomenon into the open for discussion. ACKNOWLEDGMENTThe author's thanks are due to Mr. L. F. Harza, who greatly stimulated his interest in turbine performance, and to Mr. George A. Jessop, for suggestions and data. Di iscussionL. F. IIARZA. 8 The author has urged the use of a valuable form of diagram in which to present hydraulic-turbine test data designed to display the characteristics of the turbine vividly and clearly. This form of turbine characteristic curves was used extensively in the first and subsequent editions of a text by Daniel W. Mead, 9 first published in 1908, on which the writer collaborated, except with a natural instead of logarithmic horizontal scale. The logarithmic scale adds little, if anything, to the diagram except the N, lines become straight instead of curved.Many years ago the writer developed standard platting paper for this type of curve with a sufficient range of horizontal and vertical scales so that any turbine then being built could be platted on this paper. 10 The N, lines were curved because of natural scale. The position of the set of turbine curves on the sheet indicated the type of turbine. Thus a turbine of high 8