Vízügyi Közlemények, 1962 (44. évfolyam)
4. füzet - IX. Könyvismertetés
(48)* areas for a nozzle pattern designed in terms of Rh, for a square one with an overlap corresponding to the pipe lengths, and for a triangular one are shown in Figs. 19, 20 and 21, respectively. Spray patterns and effectively irrigated areas obtained with a rectangular nozzle pattern in the case of full-circle spraying is illustrated in Fig. 22, while with 240 degree sector spraying in Fig. 23. The same data for 240 degree sector spraying in a triangular nozzle pattern are given in Fig. 24. Characteristic values obtained for the Sz — 2 type nozzle have been compiled in Table III. As to be seen clearly from the figures and tables introduced, the uniform distribution of irrigation water over the area, which has been repeatedly claimed as an advantage of sprinkling irrigation, is usually not realized, although irrigation under calm conditions has been assumed. On windy days the results are considerably worse . The value of the coefficient ß is most favourable in the case of full-overlap triangular, rectangular, and full-overlap spuare nozzle patterns. Yet the labour requirement, respectively, in the case of permanent pipe installations, the necessary pipe length, are excessive for the full-overlap patterns. In the case full-circle spraying, the highest value for the coefficient y is obtained with a rectangular nozzle pattern. In view of the above considerations, the nozzle types MR—SO and Sz—2 r having the i—R diagrams investigated, are preferably applied for full-circle spraying in a rectangular nozzle pattern. It has been demonstrated by these studies that a more uniform spray distribution can be attained only if the nozzle pattern is selected with due regard to the shape of the i—R diagram, and vice versa. It is suggested that subsequent nozzle designs should not be prepared until the most suitable nozzle pattern, and the necessary shape of the i—R diagram for the selectednozzlepattern have been determined to ensure over the irrigated area an appreciably more uniform spray distribution, with due allowance for overlaps. A nozzle ensuring the desired shape of the i—R diagram should be designed. Typical sections and spray patterns obtained with improved diagrams for a square nozzle pattern are shown in Figs. 26 to 28, while for a triangular one in Fig. 30. (Translated by Z. Szilvdssy ) LA REPARTITION DES PRECIPITATIONS DE L'IRRIGATION EN PLUIE EN FONCTION DE LA JUXTAPOSITION DES SURFACES D'ASPERSION DES ARROSEURS par F. Liptdk (Voir texte hongrois p. 369) Les avantages de l'irrigation en pluie ne peuvent être mis à profit qu'en employant des installations d'aspersion de construction adéquate aux points de vue hydraulique et mécanique, en choisissant une juxtaposition adéquate des surfaces d'aspersion des arroseurs et avec une exploitation rationelle. Pour qu'une irrigation en pluie puisse se qualifier de satisfaisante il faut que la répartition des précipitations sur le terrain soit autant que possible uniforme. L'auteur s'occupe des divers modes de la juxtaposition des surfaces d'aspersion des arroseurs et expose d'une part une méthode pour déterminer les modes de juxtaposition — assurant la répartition la plus uniforme des précipitations — à employer dans la pratiqué et propose d'autre part au constructeur de fabriquer des arroseurs, dont la courbe caractéristique i—R assure une répartition des précipitations considérablement plus uniforme que jusqu'à présent. L'étude examine les indices rencontrés jusqu'ici dans la littérature et en propose l'introduction de quelques nouveaux, plus caractéristiques que ceux employés jusqu'ici.
