Vízügyi Közlemények, 1963 (45. évfolyam)

4. füzet - VIII. Könyvismertetés

"(14) 2. Hankó Z.: Determination oî gage relationship for closely spaced gages on natural watercourses. (For the Hungarian text see pp 74) Steady regimes are infrequent on natural watercourses, but Chézy'S formula remains valid if applied to the slope of the energy gradient. The differential stage between two gages can accordingly be determined from Eq. (1/a), for which the constant Q can be obtained by Eq. (2/a). For illustrating the method let us consider the Nagymaros Section of the Danube River (Fig. 1), where extensive investigations are carried out in the interest of hydroelectric development. On the basis of observation data (Fig. 2) the relationship A = f(H) constructed from these data and plotted in Fig. 3 can be calculated also from Eqs. (14) and (15). The relationship expressed in Eq. (1/a) for the differential stage zl between the two adjacent gages is seen to be corroborated by the derivation introduced by Eqs. (9) to (15). 3. Hernádi) A.: Operating criteria for automatic headwater regulators (For the Hungarian text see pp. 80) The forces acting on the headwater regulator designed for controlling automatically the water level in irrigation canals are shown in Fig. 1. The effect of forces resulting from differential head can be eliminated if their resultant can be controlled on the basis of the equilibrium Eqs (1) and (2) to make the magnitude of ensuing moments a function of the tilting angle a of the gate. From among the terms included in the operation equation G

3 с sin a = = F (a + Л a) cos a, it is Sin a which varies with gate opening and which is of decisive importance. In order to provide operating stimulus for Lhe installation full opening should occur at about a = 0,5 to 1 deg., rather than in lhe horizontal position. The dimensions of the float should be selected with the help of Fig. 8. Particular care Should be exercised during installation to satisfy accurately the operating conditions. As a further development of the equipment a watersurface regulator equipped with downstream floats as well has been constructed (Fig. 10) which is being tested. REVIEW 1. Tidal power stations and tiie application oi tubular turbines in France. Reviewed by L. Muszkalay after papers presented in Mémoires et Travaux de la Société Hijdrotechnique de France, Vol. I., 1962. A decisive step in harnessing tidal energy has been the development of tubular turbines, which can be associated mainly with the firm Neyrpic. The first tidal power station will be realized at the mouth of the Ranee River, where it discharges into the English Channel. In view of the theoretical significance of tidal power development a great number of detailed experiments were carried out in connection with the project, the results of which, together with the construction work, are described. 2. The "Limniphon" tele-reporting gage. Reviewed by I. Zsuffa, after Lugiez, F. and André, H. The new gage introduced in France is connected to the telephone network and can be dialled from any Station. It announces the momentary and immediately precedent stages. 3. Hydroelectric development in the Nile \alley. Reviewed by M. Merényi, after Keller, E. in Water Power. The main basis of the economy in Soudan and Egypt has been the water of the Nile, which has so far been utilized for irrigation only. The power stations of 350 and 15 MW capacity constructed in combination with the Asswan and Sennar dams, respectively, consitute the first step towards hydroelectric development.