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The paper presents an analytical two-dimensional model of two-phase turbulent jets with focus on fuel sprays in internal combustion engines. The developed model allows prediction of the fuel spray parameters including local fuel concentration and mixture velocity. The model proposed in this paper is based on the single-phase steady-state laminar axisymmetric jet flow field solution by Schlichting. This solution is amended to include transport of the discontinuous fuel phase in a stagnant air in the limit of a dilute fuel concentration. This two-phase jet flow model admits a closed form analytical solution for the fuel concentration distribution. This solution is then applied to turbulent jet flow as per the approach described by Schlichting and in other studies, and used to predict point-wise properties of fuel sprays in internal combustion engines. The results of model simulations are compared with the available experimental data.

Many motor vehicles (fire-fighting cars and trucks, helicopters, airplanes, etc.) are used for conflagration extinguishing purposes. It is clear that their engines aspirate air containing combustion inhibitors, which are used for flame suppression, but until now there is no available information about the influence of this fact on engine performance. This paper presents results of an experimental study on the influence of combustion inhibitors, such as Halon 1301 (CF₃Br) and CO₂, contained in the ambient air, on the performance of compression ignition (CI) and spark ignition (SI) engines. Substantial differences in the response of CI and SI engines to the inhibitor presence in the aspirated air are revealed. Starting from relatively small concentrations of CF₃Br, an increase of the CI engine speed and a simultaneous decrease of the brake specific fuel consumption are observed. The speed rise may attain up to 80% of its initial value.

At present the market of Wankel engines is limited to some special applications. This fact explains absence of commercial software products specially developed for this engine simulation and prediction of its performance. Conversely, there are available and widely used software products for simulation of reciprocating-piston engines performance. Some attempts are known in using this software for prediction of Wankel engine performance. This paper details an approach used in these attempts. Main differences between both types of engines are summarized and principles of a virtual reciprocating-piston engine compilation are developed. A method of virtual blowing was developed for assessment of discharge coefficients for intake and exhaust ports. Comparison of simulation results with the measured performance of two UAV Wankel engines showed sufficient accuracy of the suggested approach.