發(fā)布時間：2018-08-28 05:57

【摘要】：近年來,灰霾天氣頻發(fā),對環(huán)境及人體健康造成了嚴重的危害。病理學研究表明灰霾顆粒對環(huán)境及人體健康的危害程度一方面取決于顆粒尺度,另一方面取決于顆粒組分及形態(tài)。故而,簡單的單組分顆粒群模型已經(jīng)不能充分的揭示灰霾顆粒的復雜性。本文正是在這樣背景下,利用理論分析及數(shù)值模擬來研究二組分顆粒群尺度及組分分布規(guī)律。首先,論文分析二組分顆粒群平衡方程在與組分有關凝并核情形時的解析解。這里分析組分的凝并率,并主要關注與組分有關的凝并核模型(,;',')(,'')a b a b a b a bK v v v v?k?v?v?v?v。利用拉普拉斯變換及LagrangeCharpit方法,得到了與組分有關的加法核以及乘法核時方程的解析解。通過對與組分有關加法核解的分析,我們發(fā)現(xiàn)在給定的顆粒類中,顆粒越大組分混合的越好,并且在較大顆粒類中,a組分趨于正態(tài)分布,在長時間演化后其分布與參數(shù)?無關。而對乘法核解析解分析發(fā)現(xiàn),在凝膠化發(fā)生前后,參數(shù)?對顆粒組分分布的影響有明顯的差異。其次,論文研究顆粒在長時間演化后尺度及組分的分布規(guī)律。對與組分無關及與組分有關的經(jīng)典凝并核,分別研究了在scaling極限(時間趨于無窮,平均尺度趨于無窮時使得scaling變量為常數(shù))下二參數(shù)scaling函數(shù)。發(fā)現(xiàn)對與組分有關的加法核,二參數(shù)scaling函數(shù)也滿足Vigil-Ziff猜想。這一結果將Vigil-Ziff猜想推廣至凝并與組分有關的情況。再次,論文對二組分顆粒群凝并的數(shù)值方法做了思考。在Simmel的單組分線性離散法(LDM)的基礎上,論文發(fā)展了二組分線性離散法。用發(fā)展的二組分線性離散法模擬了兩種典型工況,并把模擬結果與理論結果進行比較,二者擬合的較好。這一方法彌補了Bott發(fā)展的二維線性流量法(TFM)只能處理單組分顆粒占優(yōu)的工況這一缺陷。最后,論文通過數(shù)值模擬分析亞微米灰霾顆粒的組分分布�？疾炝藖單⒚最w粒(PM1.0)在布朗凝并機理下,痕量重金屬元素在灰霾顆粒中的組分分布形式。發(fā)現(xiàn)在較大灰霾顆粒類中重金屬物質(zhì)含量逐漸增加并且其粒徑分布趨于正態(tài)分布;較小粒徑的灰霾顆粒中重金屬物質(zhì)質(zhì)量百分比滿足冪律關系。本文對經(jīng)典核所得到的理論分析及數(shù)值模擬結果,可以為現(xiàn)實條件下凝并對灰霾顆粒尺度及組分分布的影響研究提供參考。
[Abstract]:In recent years, haze weather frequent, to the environment and human health caused serious harm. Pathological studies show that the degree of haze particles harm to the environment and human health depends on particle size on the one hand and on particle composition and morphology on the other. Therefore, the simple one-component particle swarm model can not fully reveal the complexity of haze particles. In this paper, theoretical analysis and numerical simulation are used to study the size and distribution of two-component particle groups. Firstly, the analytical solution of two-component particle group equilibrium equation in the case of conucleation is analyzed. In this paper, the coagulation rate of the components is analyzed, and the major concern is the coagulation and nucleation model () a b a bK v'). By using Laplace transform and LagrangeCharpit method, the analytical solutions of the additive kernel and the multiplicative kernel are obtained. Through the analysis of the additive kernel solutions related to the components, we find that the larger the particles are, the better the mixing of the components is, and the larger the particles are, the more the components tend to be normal distribution, and the distribution and the parameters of the larger particles tend to be normal after a long period of evolution. Nothing. The analysis of the analytic solution of multiplicative kernels shows that before and after gelation, the parameters? There are obvious differences on the distribution of particle components. Secondly, the size and component distribution of particles after long time evolution are studied. In this paper, we study the two-parameter scaling function under the scaling limit (when the time tends to infinity and the mean scale tends to infinity) for the classical conjunctive kernels which are independent of components and are related to components. It is found that the two-parameter scaling function satisfies Vigil-Ziff 's conjecture for additive kernels related to components. This result extends Vigil-Ziff 's conjecture to the case of coagulation and component-related conditions. Thirdly, the numerical method of two-component particle agglomeration is discussed in this paper. Based on Simmel's one component linear discretization method (LDM), a two component linear discretization method is developed in this paper. Two typical conditions are simulated by using the developed two-component linear discrete method. The simulation results are compared with the theoretical results and the results are fitted well. This method makes up for the defect that the two-dimensional linear flow method (TFM) developed by Bott can only deal with the condition where single component particles are dominant. Finally, the composition distribution of submicron haze particles is analyzed by numerical simulation. The distribution of trace heavy metal elements in haze particles under Brownian condensation mechanism of submicron particles (PM1.0) was investigated. It was found that the content of heavy metals in the larger haze particles increased gradually and the particle size distribution tended to be normal, and the mass percentage of heavy metals in the haze particles with smaller particle size satisfied the power law relationship. The theoretical analysis and numerical simulation results obtained from the classical nuclei can provide a reference for the study of particle size and component distribution of haze in practical conditions.
【學位授予單位】：上海大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：X513;O211.3

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