共查询到20条相似文献,搜索用时 31 毫秒
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民航飞机在LTO起降阶段的飞行中,发动机污染物排放的源强和空间位置是动态的.为准确定量评估其影响,构建了飞机LTO污染排放影响评估耦合模型.首先利用飞行动力学模型,模拟飞机LTO飞行轨迹,并获得轨迹中每一位置点的性能参数(实时燃油流量);再通过排放计算模型,确定每一位置点的污染物排放量(源强);在此基础上,基于拉格朗日烟团模型,针对飞机烟团排气特点进行修正,实现污染扩散模拟.最后采集了一架典型飞机在一个完整LTO飞行过程中的机载数据,结合实时气象参数,进行了实例应用研究.结果显示.在LTO过程中NOx、SO2、CO、PM和HC的平均排放速率分别为17.71、2.21、1.05、0.20和0.03g/s;飞机在起飞离地时刻,烟团扩散范围集中于跑道附近及侧向300m、纵向3000m范围内,NOx地面最大浓度超过100mg/m3;当飞机爬升至混合层顶完成起飞时,地面污染物扩散至侧向1200m范围,NOx浓度降至298.5μg/m3,依然较为严重,其他污染物地面浓度相对较低. 相似文献
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以移动烟团积分模式为基础,采用数学模型分析法,从理论上导出了小风和静风状态下的TSP大气扩散模式。该模式描述了重力沉降和地面不完全反射对颗粒物大气扩散过程的影响;与现有的大气扩散模式体系完全相容,可以方便地应用于小风和静风状态下TSP地面浓度的预测计算 相似文献
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为了预测汽车排放污染物的浓度,应用简化的高斯烟团模式得到静风条件下的线源扩散预测模式。并结合高斯烟流扩散模式,建立了预测汽车污染物在任意风向下和年平均浓度的预测模式,考虑车道上存在车辆行驶的强烈机械扰动湍流和把繁忙的公路视为线源两个因素,提出了计算初始扩散参数的方法。然后,运用Turner和Pasquill扩散参数,建立了线源扩散参数的确定方法。该模式应用于预测高速公路沿途汽车污染物的浓度表明,计算值与监测值吻合较好,可用于我国公路环境影响的评价。 相似文献
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Regionalairqualitypredictionmodelsusingtheknowledge-basedsystemapproachDuMin;BaiNaibin;YaoGuian(ResearchcenterforEco-Environm... 相似文献
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SRDAAR-QNPP:a computer code system for the real-timedose assessment of an accident releasefor Qinshan Nuclear Power Plant 总被引:2,自引:0,他引:2
SRDAAR-QNPP:acomputercodesystemforthereal-timedoseassessmentofanaccidentreleaseforQinshanNuclearPowerPlantHuErbang;WangHan(Ch... 相似文献
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《Atmospheric Environment. Part A. General Topics》1992,26(14):2523-2535
A simple Lagrangian puff trajectory model and its software implementation, STRALE, are described. Standard meteorological data are used as input for the simulation of the three-dimensional atmospheric transport and dispersion of a pollutant released by a point source. The schemes adopted to describe the vertical diffusion and the interaction with the mixing layer are discussed on the basis of the comparison between simulated and measured 137Cs activities for the Chernobyl nuclear accident. 相似文献
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研究表明:CALPUFF模式是运用于广域的大气扩散模型,在区域范围较大的复杂地形条件下的应用具有突出的优势.利用CALPUFF大气扩散模型模拟漳州市2009年气象场和污染物浓度场,采用监测值对模拟结果进行验证表明模型的适用性;基于现状污染源,建立大气污染物传递系数矩阵,结合线性优化法测算了不同环境空气质量标准下漳州市大气环境容量. 相似文献
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《Atmospheric Environment. Part B. Urban Atmosphere》1993,27(1):105-120
A time-dependent finite difference model in three levels combined with a puff model to account for subgrid effects close to single sources was used to calculate hour-to-hour concentration distributions. Measurements from several selected stations were used to account from time variation in background concentrations. For each hour, weight was given to observed values in areas that were not influenced by local sources.Results of concentration calculations based on hourly data on emission and dispersion are validated by measured time series of SO2 and NOx at five stations. A combination of hourly nephelometer readings and 12-h measurements of small particles at three stations are compared with calculated values.Hourly observed and calculated values from two periods (3 January–15 March 1988 and 18 April–24 June 1988) were used for the evaluation of the model for calculating hourly pollution concentrations in each square kilometre. The results showed that prediction of short-term average concentrations (e.g. hourly data) are usually poorly correlated with observations at the same time and location. Slight displacement errors may cause point-to-point correlation to be poor as a result of errors in input data.The pattern of NOx concentration variation with time was reproduced well at all stations. A subgrid model taking into account the influence of nearby roads would probably improved the model for NOx at some stations. For SO2 and small particles, industrial sources have the dominant influence and the correspondence between observed and calculated values were improved by taking into account spatial uncertainty and an hourly variation in background concentrations. 相似文献
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《Atmospheric Environment. Part A. General Topics》1992,26(9):1771-1781
Three-dimensional numerical models were used to simulate wind and turbulence distributions in the Mohave Valley and plume transport from the Mohave Power Project, located at approximately 120 km south-south-east of Las Vegas, NV. The Modeled meteorological variables were input to a three-dimensional random-puff diffusion model to simulate observed tetroon trajectories and ground-level concentrations of SO2 in the Valley. Numerical simulations indicated that hourly averaged surface concentrations could differ considerably, even when the mean and turbulence variables of the airflows were kept statistically identical. The concentration variations resulted from the differences in initial turbulence velocity and inhomogeneous distributions of airflows that each puff encountered during transport. Because the range of variations is, in general, unknown for both measurements and simulations, it is difficult to assess the representativeness of the observed and simulated values, and therefore to evaluate quantitatively the modeled concentrations against observations. 相似文献
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大气环境质量预测模型研究 总被引:9,自引:0,他引:9
为适应青岛和贵阳地区地形和大气流场复杂的特点,吸收高斯烟云模式和烟团模式的优点,建立高斯轨迹烟云模式,模式同时考虑静风条件下的扩散。应用青岛和贵阳的实测数据对模式的性能进行检验,结果证明,该模式可适用于地形和流场复杂的地区。该模式是环境决策支持系统的一部分。 相似文献
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利用CALPUFF空气质量扩散模型模拟了三明市2011年气象场和二氧化硫、二氧化氮和可吸入颗粒物浓度场,利用监测值对模拟结果进行验证表明了模型的适用性;并基于三明市现状污染源,建立大气污染物传递系数矩阵,结合线性优化模型分别测算了三明市现状环境空气质量标准和新标准下的大气环境容量,并进行比较。研究结果表明,目前三明市主要大气污染物尚有较大的环境容量,但是需要严格控制大气污染物特别是工业和机动车尾气产生的氮氧化物的排放。 相似文献
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圆筒形电化学反应器中有机物电催化的传递特性研究 总被引:1,自引:0,他引:1
研究了圆筒形电化学反应器内有机物在电化学降解过程中的传递特性.假设废水以平推流方式通过圆筒形反应器,由电催化过程的质量守恒和法拉第定律导出浓度、电流强度随废水停留时间的变化规律.根据废水中有机物的电化学降解和有机物氧化分解的关系将浓度分布转换成COD分布,并考察了扩散对COD、电流强度分布的影响理论模型和实验数据表明,在传质控制条件下忽略与不忽略扩散的影响,COD、电流强度的分布遵循不同的指数关系.理论模型与实验数据的平均误差为8.6%;极限电流随电解质流量的变化而改变. 相似文献
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佛山市中心城区工业污染源排放的数值模拟 总被引:6,自引:3,他引:3
以广东省佛山市中心城区为研究区域,在分析城区工业污染源排放与分布特征的基础上,应用中尺度气象模式MM5耦合空气质量模式CALPUFF的方法,模拟了中心城区工业污染源排放SO2的扩散传输过程. 在考虑周边污染源及本地污染物的情况下,发现ρ(SO2)模拟值与实测值的变化趋势一致,表明模拟方案可较好地反映ρ(SO2)的时空分布特征. 分析中心城区工业源排放时空分布模拟结果发现,工业污染源排放与分布特征和气象环境是影响城区工业源排放SO2的时空分布的重要因素. 相似文献
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北京地区FLEXPART模式适用性初步研究 总被引:6,自引:3,他引:3
FLEXPART是挪威大气研究所开发的拉格朗日粒子扩散模式.为客观地评价该模式在北京地区的适用性,以北京上甸子大气本底站为例,模拟了CO浓度变化及其源区分布特征,并与该站实测CO浓度和2006年排放源清单进行了比对.结果表明:①模式模拟的CO浓度变化趋势可以较好地反映上甸子地区CO浓度的日变化规律,CO浓度的模拟值与实测值的相关系数在春夏两季分别达到0.42和0.41;②春夏两季北京市污染气团主要源地分布在西-西南和西西南-南-南南东扇区,模式结果较好地体现了北京及周边地区CO源区的分布特征.初步研究表明,FLEXPART模式在北京地区是基本适用的. 相似文献