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This paper presents a separate ε - NTU calculation method. This method can be used not only in calculating the inlet and outlet status parameters of cold and hot fluid streams in the intercooler, but also in calculating many thermal parameters such as all the status parameters of cold and hot fluid streams, wall temperature, heat flux, and convective heat transfer coefficients. As an example, the authors simulate the temperature distributation in the intercooler of 6130Q turbo - intercooled diesel engine. The law of fluid flow and heat transfer process is revealed.

Butanol, which is a renewable biofuel, has been regarded as a promising alternative fuel for internal combustion engines. When blended with diesel and applied to pilot ignited natural gas engines, butanol has the capability to achieve lower emissions without sacrifice on thermal efficiency. However, high blend ratio of butanol is limited by its longer ignition delay caused by the higher latent heat and higher octane number, which restricts the improvement of emission characteristics. In this paper, the potential of increasing butanol blend ratio by adding hot exhaust gas recirculation (EGR) is investigated. 3D CFD model based on a detailed kinetic mechanism was built and validated by experimental results of natural gas engine ignited by diesel/butanol blends. The effects of hot EGR is then revealed by the simulation results of the combustion process, heat release traces and also the emissions under different diesel/butanol blend ratios.

In recent years, with the development of CFD technology, numerical simulation is becoming an important method to study the in-cylinder spray and combustion process of internal combustion engine. Consequently the appropriate selection of mathematical models is very important, which will determine directly the accuracy of calculation results in IC engine numerical simulation. In this paper, the EDC and ECFM-3Z combustion model was introduced respectively, and the latter was emphasized on. Finally it was decided to use ECFM-3Z model to simulate the combustion process of a 4-valve DI diesel engine for its advantages. Through comparison and analysis, it is found that the computation results of the in-cylinder pressure peak, RoHR and emission products have excellent agreement with experimental data. Accordingly the research results show that the ECFM-3Z model reveals the DI diesel combustion process closely, and forecasts the formation of exhaust emissions accurately.

In the present study, an improved multi-dimensional CFD code has been used to simulate the mixture formation and combustion process of a DI diesel engine. WAVE breakup model constants C0 and C1 are modified according to a linear expression, which is a function relation to the gas pressure in-cylinder. Reasonable agreements of the measured and simulated data of in-cylinder pressure, mean temperature, NOx and soot emissions were achieved for different engine operation conditions. At the same time, the effects of different spray angles on the diesel engine mixture formation and combustion have been further simulated based on the improved multi-dimensional fuel spray and combustion models. The influence of different testing conditions mentioned above on the PM and gaseous pollutant was also discussed in this paper. Predicted trends of soot and NOx formation are also presented together with the corresponding measured data.