The atmospheric aerosol dynamics model (AADM) has been widely used in both comprehensive air quality model systems and chemical transport modeling globally. The AADM consists of Smoluchowski's coagulation equation (SCE), whose solution undergoing Brownian coagulation in the free molecular regime is a challenge because it is inconsistent with aerosols whose size distribution cannot exactly follow the lognormal size distribution. Thus, a new method for solving the SCE without assuming lognormal size distribution is proposed and developed. The underlying principle of this method is that the hybridization of the well‐established method of moments with the assumed lognormal size distribution (log MOM) and Taylor‐series expansion method of moments (TEMOM) is implemented. This method shows excellent agreement with the sectional method (SM) which is used as reference. The accuracy of these two specific models closely approaches that of the TEMOM, but overcomes the limitation of the classical log MOM. The computational time of this scheme is considerably lower than that of the SM. The new method was successfully implemented to reveal the formation and growth of secondary particles emitted from a vehicle exhaust tailpipe. It was found that the formation of new particles only occurs in the interface region of the turbulent exhaust jet (which is very close to the tailpipe exit), whereas no new particles are formed in the mixture of the exhaust jet plume and the surrounding cold air downstream. The new method is verified as an efficient and reliable numerical scheme for studying atmospheric aerosol dynamics.

中文翻译：

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模拟大气气溶胶生长的矩的有效方法：模型描述，验证和应用

大气气溶胶动力学模型（AADM）已在全球范围的综合空气质量模型系统和化学物质运输模型中广泛使用。AADM由Smoluchowski的凝结方程（SCE）组成，其溶液在自由分子状态下经历布朗氏凝结是一个挑战，因为它与气溶胶的大小分布不能完全遵循对数正态大小分布不一致。因此，提出并开发了一种在不假设对数正态分布的情况下求解SCE的新方法。该方法的基本原理是，将完善的矩量方法与假定的对数正态尺寸分布（log MOM）和泰勒级数矩量展开方法（TEMOM）进行混合。此方法与用作参考的分段方法（SM）表现出极好的一致性。这两个特定模型的准确性非常接近TEMOM的准确性，但克服了传统log MOM的局限性。该方案的计算时间大大低于SM的计算时间。成功实施了新方法，以揭示从车辆排气尾气管排放的二次颗粒的形成和生长。发现新颗粒的形成仅发生在湍流排气口（非常靠近排气管出口）的界面区域中，而在排气羽流和周围冷空气的混合物中没有形成新颗粒。下游。验证了该新方法是研究大气气溶胶动力学的有效且可靠的数值方案。