期刊名称：Bulletin of the Institute of Heat Engineering
印刷版ISSN：2083-4187
出版年度：2017
卷号：97
期号：1
页码：1
语种：English
出版社：Warsaw University of Technology
摘要：In this study n-heptane spray in supercritical environments was simulated using commercial CFD (Computational Fluid Dynamic)software AVL Fire. The numerical results were analyzed in terms of global spray parameter, and spray penetration.The results obtained were compared with experimental data available at Sandia National Laboratories. N-heptane spray simulationswere performed in the same conditions as in the Sandia experiments. The goal of the study was to assess whetherthe Lagrangian approach performs well in engine relevant conditions in terms of spray global parameters. Not included inthis assessment was the influence of supercritical mixing on liquid-gas interphase. The major element was the potential forpractical application of the commercial CFD code in terms of properly representing global spray parameters and thus mixtureformation in supercritical conditions, which is one of the core aspects in whole engine process simulation. The key part ofthe study was mesh optimization. Therefore, the influence of mesh density on both the accuracy of calculations and thecalculation time was determined, taking into consideration detailed experimental data as initial conditions for the subsequentcalculations. This served as a basis to select the optimal mesh with regard to both accuracy of the results obtained and timeduration of the calculations. As a determinant of accuracy, the difference within a range of evaporated fuel stream was used.Using selected mesh the set of numerical calculations were performed and the results were compared with experimental onestaken from the literature. Several spray parameters were compared: spray tip penetration, temperature of the gaseous phaseand mixture fraction in the gaseous phase. The numerical results were very consistent in respect of spray tip penetration. Theother parameters were influenced by specific features of the Lagrangian approach. Nevertheless the results obtained showedthat the Lagrangian approach may be used for engine relevant conditions.
其他摘要：In this study n-heptane spray in supercritical environments was simulated using commercial CFD (Computational Fluid Dynamic) software AVL Fire. The numerical results were analyzed in terms of global spray parameter, and spray penetration. The results obtained were compared with experimental data available at Sandia National Laboratories. N-heptane spray simulations were performed in the same conditions as in the Sandia experiments. The goal of the study was to assess whether the Lagrangian approach performs well in engine relevant conditions in terms of spray global parameters. Not included in this assessment was the influence of supercritical mixing on liquid-gas interphase. The major element was the potential for practical application of the commercial CFD code in terms of properly representing global spray parameters and thus mixture formation in supercritical conditions, which is one of the core aspects in whole engine process simulation. The key part of the study was mesh optimization. Therefore, the influence of mesh density on both the accuracy of calculations and the calculation time was determined, taking into consideration detailed experimental data as initial conditions for the subsequent calculations. This served as a basis to select the optimal mesh with regard to both accuracy of the results obtained and time duration of the calculations. As a determinant of accuracy, the difference within a range of evaporated fuel stream was used. Using selected mesh the set of numerical calculations were performed and the results were compared with experimental ones taken from the literature. Several spray parameters were compared: spray tip penetration, temperature of the gaseous phase and mixture fraction in the gaseous phase. The numerical results were very consistent in respect of spray tip penetration. The other parameters were influenced by specific features of the Lagrangian approach. Nevertheless the results obtained showed that the Lagrangian approach may be used for engine relevant conditions.
