Simulation of chemical interaction of combustion products with air behind the exit section of nozzles aircraft engine

One of important operational phases of planes is an engine runup - check of operability of engine aircraft power units on the platforms which are specially equipped with blast fence. Duration of this stage depends on the engines installed on planes and can reach 30 minutes, such as for the An-12 plane considered in this article. Thus the pollutants formed as the result of fuel combustion cover the territory of a place for approbation of engines and cause the considerable environmental loss. Objective of this research is model construction for the analysis of behavior of streams of combustion gases at collision with a blast fence and the analysis of possible chemical reactions of products of fuel combustion with air oxygen. In this work I have received the qualitative and quantitative results using mathematical model of operation process of approbation of engines. As geometrical model I accepted the two-dimensional model of the plane in the plan and places for engines runup. The kinematic model describes the maximal mode of the considered process characterized by the complete combustion of fuel. Possible chemical reactions of combustion gases with oxygen of air are constructed under this condition. This task is solved by means of the Ansys Fluent software product solved. Results of calculation show that combustion gases undergo change of a trajectory (dispelling) and loss of speed when interacting with of a blast fence. Thus, the mass fractions of products of fuel combustion reach its maximum number on a nozzle exit. And the mass fractions of the substances formed during reactions with air oxygen reach its maximum number on border of streams with environment. Reaction behavior also promotes increase in area of distribution of the pollutants received as a result of oxidation in comparison with the substances set on a nozzle exit. The received analysis of processes allows to conduct the further research directed on decrease of pollution of territories for engine runup. In the future they can be applied in the airfields supplied with platforms for engine runup for the purpose of decrease of concentration of pollution concentration on aerodrome environs.