Vízügyi Közlemények, 1962 (44. évfolyam)

4. füzet - IX. Könyvismertetés

(86)* 4. Измерение расходов воды но методу Браславского. По статье Procházka; Meranie priehokoz vodij podVa Braslavského излагает Ф. Ивичич. Во время паводков измерение скорости в 3 — 4 вертикалях дает достаточно точный результат, если расчет ведется по приведенной в статье таблице. НОВЫЕ КНИГИ 1. Кезди А. и Марко И.: Защита и обезвоживание земляных сооружений. Книгу рецензирует П. Шаламин. В этом году была издана в Будапеште названная книга, имеющая 100 стр. 281 рисунка, 58 таблиц. I. глава книги занимается изысканием почвы, II. глава с определением устойчивого и экономичного наклона откосов, III. глава с вопросами основания дамб, IV. глава с методами опирания земляной массы у поверхности, V. глава с вопросами обезвоживания территории и земляных сооружений с ценным иллюстративным материалом. BRIEF PUBLICATIONS 1. Testing Pumps for Sprinkling Irrigation, by Á. Gerencsér (For the Hungarian text see ' pp. 576). Sprinkling irrigation in Hungary was practiced on 2600 hectares in 1956, and on 52 000 hectares in 1961. Instead of the pumps previously applied, and designed for other purposes, series of pumps meeting the demands better and more economically must be developed. Internal combustion engines series-produced in Hungary are listed in Table I, while agricultural tractors are compiled in Tables II through IV and Figs. 3 and 4. The pressure resulting with the 4 at. sprinkler nozzle, i.e. a manometric delivery head of 55 to 90 m, had to be adopted as design basis for the new pumps. The attainable efficiency could be improved by increasing the specific speed, or in other words single-stage, high-speed, or multi-stage pumps were called for. Such with a steep Q — H rating curve (Fig. 5J were found preferable. Rated outputs of pumping sets suggested for sprinkling equipment are given in Table VIII. 2. Simple Means for Processing Stage Data of Reeording Gages, by L. Pgber (For the Hungarian text see pp. 585). The processing of record bands of gages located on small watercourses and irrigation canals is -very time consuming. In previous practice the daily mean discharge was therefore determined a) from the mean stage, or b) on the basis of n actually observed discharges. In* order to facilitate processing work a template has been developed at the Research Institute for Water Resources, Budapest, by which the momentary discharge can be determined and the stage hydrograph can be transformed into a discharge hydrograph. The template is shown in Fig. 2, the plastic rule serving the plotting of discharges and designed for each gage specially in Fig. 4, while its use is illustrated in Figs. 4 and 5. 3. Flap Valve and Air Vent for Preventing Water Hammer in Long«Distance Pipelines, or Mains, by Sz. Schneider (For the Hungarian text see pp. 592). Water hammer in pipelines, or longer mains, following the shut-down of pumps can be avoided by resolving the line into sections by flap-vales, or automatic air vents. The lowest gradient line occurring in lines equipped with flap valves is illustrated in Fig. 1. In the case of incompressible fluids the phenomenon shown in Fig. 2. follows the shut-down of the pump. Elastic deformations of the water and the pipe wall can be allowed for as shown in Fig. 3, while the effect of automatic air vents, the reduction of the dynamical pressure gradient down to the static one is shown in Fig. 4. The simplified assumptions made in the paper must be verified by future investigations.