Research On Interior Flow-field And Performance Testing Of Irregular Area Spraying Adjustor

With the intension of world water resources shortage, water-saving irrigation techniques including the sprinkler irrigation have been the inevitable one to reduce the crisis of water shortage and to achieve the modernization of agriculture. Irregular Wetted Area Precision Sprinkler Irrigation, which is a new sprinkler irrigation technology, uses the High Uniformity Sprinklers for Irregular Wetted Area spaced together, which can eliminate the adverse influences from the circle wetted area contour on the spacing of sprinklers. This paper conducts a systematical research on the Irregular Wetted Area Precision Sprinkler Irrigation and analyzes the relation between configuration and energy losing with CFD technology. The results of this research provide theoretical basis for the design of high uniformity sprinkler for irregular wetted area.The term "High uniformity sprinklers for irregular area" is used by the authors to describe the precision irrigation sprinklers that can spray according to the continuous change of the irrigated area profile. A survey on high uniformity sprinklers for irregular spraying area was made by analyzing the present mechanism at home and abroad in this paper. The major models and components of these sprinklers were discussed. The problems which existed in the development and practice of this field in China were put forward. The realization of high uniformity sprinklers for irregular wetted area was researched by theoretical analysis in this paper. The general construction and principle of the spray distance and flow rate adjustor for the sprinkler are given by analyzing the present mechanism at home and abroad. And with examples given, both the variation principle, which describes the spray distance, and the equation, which describes the internal connection of the spray distance, flow rate and rotation speed ware derived. The equations indicate that the flow rate is proportional to the product of rotation speed and square spray distance.Based on analysis of the current state of the flow pattern modeling abroad and at home, the meaning of the mathematical simulation of the flows in the Irregular Area Spraying Adjustor is given. This paper discusses the three dimensional turbulent flow fields, using methods of mathematical analyze and CFD simulation. The flow characteristics of the adjustor are numerically studied using Realizable k-e turbulent model combined with 3D time-averaged N-S equation through commercial CFD software package FLUENT, and the results give the distribution figures of velocity, pressure, etc. in the whole flow field are obtained.After reviewing the current researches, Irregular Area Spraying Adjustor, the key component for the high uniformity sprinklers for irregular area achieving variable rate and contoured controlled is designed. The main constructional parameters are analyzed under Water Movement Partial Resistance Theory. The index system for evaluation of sprinklers' performance is given. The hydraulic parameters of the sprinkler installed with adjustor are tested, such as working pressure, water flux, the range of the sprinkler, characteristic of water distribution, etc. The experimental results indicate that the high uniformity sprinklers for irregular area not only ensure the consistency with the common standard, but also the special standard for Irregular Area Spraying.