本研究得到了國家重點研究開發(fā)項目(編號2016YFC0400202)和江蘇省現(xiàn)代農業(yè)重點研究開發(fā)項目(編號BE2018313)的資助。噴灌設備裝置的性能評價過程中用到了很多種性能指標,這些指標均為描述噴灌系統(tǒng)狀況和運行狀況,并且是可以進行測量的變量或者是可以計算的系數(shù)。噴頭是影響噴灌質量的關鍵因素,隨著低壓噴灌在世界范圍內的發(fā)展,世界上的發(fā)達國家和發(fā)展中國家都致力于研究和開發(fā)低壓高效運行的噴灌用噴頭之中。在本研究中,開發(fā)出了一種新型結構和新型工作原理的由水力驅動進行旋轉的射流式噴頭,以改善現(xiàn)有的全射流噴頭在低壓條件下的水力性能。本研究中在不同工作壓力下,對不同類型的噴嘴結構進行了眾多的試驗研究。本文的主要內容和創(chuàng)新點如下:(1)現(xiàn)有全射流噴頭的流體組成結構進行了優(yōu)化得到新型結構的射流式噴頭,并對新型噴頭進行了優(yōu)化組合研究。設計并制造出了一種由水力驅動進行旋轉的射流式噴頭和系列不同噴嘴直徑的樣機做為試驗對象。本研究中的射流式噴頭的重要結構參數(shù)包括導管長度、工作壓力、導管直徑、噴嘴直徑,并分別由因子A、B、C和D來進行表示。研究中采用了四因素三水平正交試驗設計開展了試驗研究,并采用直接分析...

【文章頁數(shù)】：154 頁

【學位級別】：博士

【文章目錄】：
ABSTRACT
摘要
CHAPTER 1: INTRODUCTION
    1.1 Research background
    1.2 Objectives, scope and structure of research
    1.3 Area equipped for irrigation
    1.4 Sprinkler
    1.5 Types of sprinklers irrigation
        1.5.1 Impact sprinkler
        1.5.2 Complete fluidic sprinkler
        1.5.3 Hand-move sprinkler system
        1.5.4 Solid set and permanent systems
    1.6 Equipment and design
    1.7 Wind drift and droplet evaporation
    1.8 Sprinkler hydraulic performance parameters
        1.8.1 Sprinkler discharge
        1.8.2 Patterns radius (throwing distance)
        1.8.3 Water application rate or intensity
        1.8.4 Distribution pattern
        1.8.5 Sprinkler droplet size
        1.8.6 Sprinkler irrigation uniformity
        1.8.7 Methods of measuring droplet size distributions
CHAPTER 2: OPTIMIZATION OF THE FLUIDIC COMPONENT OF COMPLETE FLUIDIC SPRINKLER AND TESTING OF THE NEW DESIGNED SPRINKLER
    2.1 Design of newly dynamic fluidic sprinkler head and working principle
        2.1.1 Design of the Nozzles
        2.1.2 Experimental setup and procedure
    2.2 Results and analysis of orthogonal tests
        2.2.1 Comparison of operating pressure and discharge
        2.2.2 Summary results of the orthogonal test
        2.2.3 Simulation of water distribution
    2.3 Brief summary
CHAPTER 3: NUMERICAL SIMULATIONS AND EXPERIMENTAL STUDY ON INTERNAL FLOW CHARACTERISTIC OF DYNAMIC FLUIDIC SPRINKLER
    3.1 Numerical simulation
        3.1.1 Mathematical model
        3.1.2 Rotation speed
        3.1.3 Grid sensitivity analysis
        3.1.4 Boundary conditions
        3.1.5 Experimental procedure
    3.2 Results and discussion
        3.2.1 Relationship between velocity distribution and nozzle sizes
        3.2.2 Relationship between velocity and length of the tube
        3.2.3 Comparison of the numerical simulation, calculated and experimental results
        3.2.4 Comparison of rotation speed and the nozzle sizes
        3.2.5 Relationship between rotation speed and length of the tube
        3.2.6 Effect of internal velocity distribution on hydraulic performance
    3.3 Brief summary
CHAPTER 4: EVALUATION OF HYDRAULIC PERFORMANCE CHARACTERISTICS OF THE DYNAMIC FLUIDIC SPRINKLER
    4.1 Structure and working principle of 2d-video distrometer
    4.2 Experimental procedures
    4.3 Results and discussion
        4.3.1 Comparison of water distribution profiles
        4.3.2 Comparison of computed uniformity coefficient
        4.3.3 Droplet size distributions
        4.3.4 Droplet characterization statistics
    4.4 Brief summary
CHAPTER 5: DEVELOP A MODEL TO SIMULATE THE EFFECT OF RISER HEIGHT ON ROTATION UNIFORMITY AND APPLICATION RATE OF THENEWLY DESIGNED DYNAMIC FLUIDIC SPRINKLER
    5.1 Experimental procedures
        5.1.1 Evaluation of sprinkler performance
        5.1.2 Overlap water distribution
    5.2 Results and discussion
        5.2.1 Quadrant completion time
        5.2.2 Deviation in water application intensity
        5.2.3 Comparison of water distribution profiles
        5.2.4 Overlap distribution analysis
    5.3 Brief summary
CHAPTER 6: COMPARATIVE EVALUATION OF HYDRAULIC PERFORMANCE OF A NEWLY DESIGNED DYNAMIC FLUIDIC, COMPLETE FLUIDIC, AND D#3000 ROTATING SPRAY SPRINKLERS
    6.1 Structure and the working principle of three different sprinkler heads
        6.1.1 Experimental setup and procedure
        6.1.2 Calculation of combined CUs, droplet sizes, and velocities
    6.2 Results and discussion
        6.2.1 Comparison of a radius of throw and coefficient of discharge at different operatingpressures
        6.2.2 Relationship between rotation speed for three different sprinkler heads
        6.2.3 Comparison of water distribution profiles
        6.2.4 Comparison of the computed uniformity coefficient
        6.2.5 Spray distributions in the middle and end of the range
        6.2.6 Droplet size distribution
        6.2.7 Droplet characterization statistic
        6.2.8 Droplet velocity distribution
    6.3 Brief summary
CHAPTER 7: CONCLUSIONS AND RECOMMENDATIONS
    7.1 Conclusions
    7.2 Recommendations for further research
REFERENCES
ACKNOWLEDGMENTS
PUBLICATIONS
RESEARCH PROJECTS
APPENDIX



本文編號：3842582