Assessment of vehicle emissions projections in Madrid (Spain) from 2004 to 2012 considering several control strategies

Road transport is a major source of air pollutant emissions in European cities. Moreover, vehicle exhaust emissions have been the cause of much concern about the effects of urban air pollution on human health. Local authorities need to develop strategies to control vehicular emissions through technological and socioeconomical measures. For this reason, an efficiency assessment of possible future measures to reduce air pollution is required for future traffic planning, regulatory and fiscal initiatives. This paper presents the assessment of several mobility and technology scenarios that can be used for emission reductions in Madrid (Spain) in the period 2004–2012. Pollutants considered are those related to typical air quality problems in urban areas in Europe (SO2, NOx, NMVOC, heavy metals, CO and particulate matter) and CO2 as a greenhouse gas. Results show an expected increase in mobility but a decreasing trend in future traffic-related emissions, except for CO2. This reduction is due to technological improvements linked to European Legislation for road vehicles (Euro Standards). CO2 emissions are expected to increase because the technological improvements will not be able to counteract the effect of the large mobility increase. With regard to control strategies, the most effective measure for emission reductions is fleet renewal. According to the hypotheses made in the paper, this would reduce, on average, the pollutant emission by 16.04%. With regard to CO2 emissions, the use of biofuels and the decrease in mobility are the most effective measures

Mixing performance of viscoelastic fluids in a kenics km in-line static mixer

AbstractThe mixing of ideal viscoelastic (Boger) fluids within a Kenics KM static mixer has been assessed by the analysis of images obtained by Planar Laser Induced Fluorescence (PLIF). The effect of fluid elasticity and fluid superficial velocity has been investigated, with mixing performance quantified using the traditional measure of coefficient of variance CoV alongside the areal method developed by Alberini et al. (2013). As previously reported for non-Newtonian shear thinning fluids, trends in the coefficient of variance follow no set pattern, whilst areal analysis has shown that the >90% mixed fraction (i.e. portion of the flow that is within ±10% of the perfectly mixed concentration) decreases as fluid elasticity increases. Further, the >90% mixed fraction does not collapse onto a single curve with traditional dimensionless parameters such as Reynolds number Re and Weissenberg number Wi, and thus a generalised Reynolds number Reg=Re/(1+2Wi) has been implemented with data showing a good correlation to this parameter