本文選題：散粒體　切入點(diǎn)：離散元法　出處：《東北農(nóng)業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：水田化肥深施技術(shù)可以有效提高水稻產(chǎn)量,減少肥料損失和環(huán)境的污染。水田深施肥過程中容易出現(xiàn)肥料架空、板結(jié),造成排肥堵塞,影響施肥質(zhì)量。掌握肥料在施肥裝置中的流動規(guī)律可以有助于設(shè)計合理、高效的水田深施肥裝置。肥料顆粒是農(nóng)業(yè)散粒體物料,離散元法是研究散粒體受力、運(yùn)動等方面的一種重要方法,本文采用離散元法對肥料在水田深施肥裝置中運(yùn)動過程進(jìn)行研究。根據(jù)離散元法計算要求,以大顆粒尿素肥料為研究對象,測試分析了肥料的物理力學(xué)特性參數(shù),得到肥料顆粒的離散元模型;建立了水田深施肥裝置離散元邊界模型,并確定邊界接觸類型。仿真肥料顆粒在水田深施肥裝置的不同工作狀態(tài)下的運(yùn)動過程。借助高速攝像拍攝肥料在深施肥裝置的運(yùn)動形態(tài),將試驗(yàn)結(jié)果與仿真結(jié)果進(jìn)行對比分析。主要研究工作如下:(1)通過物理力學(xué)特性測試試驗(yàn)測量了肥料顆粒的三軸尺寸、等效直徑、球形率、密度等基本物理參數(shù);得到了肥料顆粒的彈性模量、靜摩擦系數(shù)、滾動摩擦系數(shù)、碰撞恢復(fù)系數(shù)并分析了各自主要影響因素的關(guān)系,為顆粒仿真分析提供了參數(shù)依據(jù)。(2)采用仿真與試驗(yàn)結(jié)合的參數(shù)標(biāo)定法,通過分析球形顆粒和手動填充的不規(guī)則球形顆粒的休止角及不同參數(shù)的影響關(guān)系,驗(yàn)證了單個肥料顆粒參數(shù)測量對群體顆粒運(yùn)動仿真建模的有效性。綜合仿真效率,得到了肥料顆粒離散元模型。(3)以安裝有螺旋鋼絲為擾動部件的水田深施肥裝置為研究對象,為仿真試驗(yàn)設(shè)計了簡化的肥箱結(jié)構(gòu),確定了肥箱的運(yùn)動參數(shù)和材料屬性,建立了水田深施肥裝置的離散元分析實(shí)體邊界模型。選擇顆粒之間、顆粒與深施肥裝置模型之間的接觸計算方法。(4)仿真分析了肥料在有無轉(zhuǎn)動螺旋鋼絲情況下的落肥過程以及螺旋鋼絲的結(jié)構(gòu)參數(shù)對肥箱排肥的影響仿真、肥箱開口直徑對肥箱工作狀態(tài)的影響仿真。觀察肥料顆粒在不同工作條件下的流動形態(tài),分析了不同裝置結(jié)構(gòu)對顆粒流動的影響。(5)采用高速攝像技術(shù)對肥料顆粒運(yùn)動過程進(jìn)行判別分析。將試驗(yàn)分析結(jié)果與仿真結(jié)果進(jìn)行對比,初步證明了肥料顆粒計算參數(shù)選取的合理性和采用離散元法分析肥料顆粒與施肥裝置機(jī)械部件接觸作用的可行性,為肥料顆粒建模、水田深施肥裝置的設(shè)計建立了一種新方法。
[Abstract]:Deep application of fertilizer in paddy fields can effectively increase rice yield, reduce fertilizer loss and environmental pollution. Mastering the flow rule of fertilizer in fertilizer plant can be helpful to design rational and efficient deep fertilizing device in paddy field. Fertilizer particle is agricultural granular material, discrete element method is to study the force of loose grain. In this paper, a discrete element method is used to study the movement process of fertilizer in a paddy field deep fertilizing plant. According to the requirements of discrete element method, a large granular urea fertilizer is used as an object of study. The parameters of physical and mechanical properties of fertilizer were measured and analyzed, and the discrete element model of fertilizer particle was obtained, and the discrete element boundary model of paddy field deep fertilization device was established. The boundary contact type was determined, and the movement process of fertilizer particles in different working states of paddy field deep fertilization device was simulated. The motion pattern of fertilizer in deep fertilization device was photographed by high speed camera. The main research work is as follows: 1) the basic physical parameters such as triaxial size, equivalent diameter, spherical rate, density and so on are measured by physical and mechanical properties test. The elastic modulus, static friction coefficient, rolling friction coefficient and impact recovery coefficient of fertilizer particles were obtained. The parameter calibration method combined with simulation and experiment is used to analyze the angle of repose of spherical particles and the influence of different parameters on the angle of repose of spherical particles and the irregular spherical particles filled by hand. The effectiveness of single fertilizer particle parameter measurement on simulation modeling of mass particle motion was verified. The discrete element model of fertilizer particle was obtained by synthesizing the simulation efficiency. The paddy field deep fertilizing device with spiral steel wire as disturbance component was used as the research object. The simplified fertilizer box structure was designed for the simulation test, the motion parameters and material properties of the fertilizer box were determined, and the discrete element analysis entity boundary model of the paddy field deep fertilization device was established. The contact calculation method between particle and deep fertilization device. (4) Simulation analysis of fertilizer falling process under the condition of rotating spiral steel wire and the influence of structural parameters of spiral steel wire on fertiliser discharge. Simulation of the influence of the opening diameter of the fertiliser box on the working state of the fertiliser box. The effect of different device structures on particle flow is analyzed. (5) High-speed camera technology is used to discriminate and analyze the motion process of fertilizer particles. The experimental results are compared with the simulation results. The rationality of calculating parameters of fertilizer particles and the feasibility of using discrete element method to analyze the contact between fertilizer particles and mechanical parts of fertilizer plant were preliminarily proved. A new method was established for modeling fertilizer particles and designing a deep fertilizing device in paddy fields.
【學(xué)位授予單位】：東北農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S224.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 袁釗和;水田化肥深施技術(shù)的研究[J];中國農(nóng)機(jī)化;1996年05期

2 張福鎖,陳新平,馬文奇;“現(xiàn)代農(nóng)業(yè)”時代談化肥[J];磷肥與復(fù)肥;2003年01期

3 奚振邦;化肥與農(nóng)業(yè)——簡析化肥對現(xiàn)代農(nóng)業(yè)的作用[J];磷肥與復(fù)肥;2003年02期

4 陳遠(yuǎn)鵬;龍慧;劉志杰;;我國施肥技術(shù)與施肥機(jī)械的研究現(xiàn)狀及對策[J];農(nóng)機(jī)化研究;2015年04期

5 楊青林;桑利民;孫吉茹;季志強(qiáng);袁文利;郭玉煒;蓋顏欣;;我國肥料利用現(xiàn)狀及提高化肥利用率的方法[J];山西農(nóng)業(yè)科學(xué);2011年07期

6 倪自豐;錢善華;羅勇;;接觸面積對天然軟骨摩擦行為的影響[J];潤滑與密封;2012年07期

7 涂仕華;化肥在農(nóng)業(yè)可持續(xù)發(fā)展中的作用與地位[J];西南農(nóng)業(yè)學(xué)報;2003年S1期

，

本文編號：1578165