Mathematical model of pollution compounds calculus in function of traffic capacity from urban areas STELIAN TARULESCU, RADU TARULESCU, ADRIAN SOICA Department of Mechanical Engineering Transilvania University of Brasov Eroilor Boulevard, No 29, Brasov ROMANIA s.tarulescu@unitbv.ro Abstract: - The Brasov city is one of the biggest towns in Romania. In the central area of the Brasov city can be found the biggest concentration of the carbon monoxide, nitrogen oxides, the ozone and the volatile organic compounds. For intersection’s analysis there were collected data about the road traffic and data about the chemical pollution in the neighborhood of the road. In order to realize the model there were made tables with the traffic values and the values of the three pollutants, in function of the intersections of the analyzed route. For calculus were used the equations corresponding to the determined polynomial curves, for each pollutant, using the values obtained experimentally. The working page of the mathematical model was made grouping the four analyzed situations. Key-Words: - Chemical, pollution, traffic, mathematical, model, etalon vehicle 1 Introduction The human activity generates the emission of many gaseous pollutants into the atmosphere. The vehicles give many pollutants, and the studies made at international level allow quantification of the pollutants from the traffic flow. From all the primary pollutants made by the internal combustion engines, there are distinguished seven significant atmospheric pollutants, brought under regulation in Europe: • sulphur dioxide (SO 2 ); • particles (with a diameter <10 μm); • lead (Pb); • nitrogen oxide (NO x ); • carbon monoxide (CO); • unburned hydrocarbons (H n C m ) – benzene; • the ozone (O 3 ) from atmosphere, in concentrations of 0.5-10[ppm] [5]. A synthesis of the traffic flow development shows three significant travel phases: - daily travels to and from work; - afternoon travels to different centers (commercial, social-cultural, of individual or group meetings); - going to and especially coming back from the week-end, generally outside the city, in order to relax. The simple enunciation of these three main phases of travel present in city’s life can prove the variety of the urban traffic flow structure and intensity, where the vehicle has the main role, having the purpose to assure the maximum comfort of the travels, by its accessibility from “door to door”. The essence of the problem is the mutual accommodation city-vehicle, its solution not being the sacrifice of one for the other. If at the big traffic flow volume of the small vehicles we add the common transportation (which in many cities has the first place in order to satisfy the travel necessary of the habitants) and the transportation of goods and services, it can be said that the traffic flow needs two categories of measures in the urban areas: - the adequate arrangement of a main road network, which can satisfy the traffic flow which is increasing continuously, but also which does not disturb the urban ambience; - the organization, regulation and control of the traffic flow in intersections, which represents for the urban traffic real intake and exhaust valves, being for the streets network their strangulation points, the ones which determine the intrinsic capacity of the traffic flow [6]. The region of Brasov is situated in a mountainous area in the centre of Romania. In Brasov County there are 4 municipalities and 5 towns, 43 communes and 150 villages. The county population registered is 626499 inhabitants, from which in the urban environment 472620 inhabitants and in rural environment 153879 inhabitants. In the central area of the Brasov City can be found the biggest concentration of the carbon monoxide, where the majority in traffic is composed by the vehicles equipped with gasoline engines, where the WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT Stelian Tarulescu, Radu Tarulescu, Adrian Soica ISSN: 1790-5079 350 Issue 4, Volume 4, April 2008