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Turbocharging industry mainly employ steady method in the design and development process in present. However, the unsteady method is becoming more important for the exploration of the advanced turbocharging technique. This paper discusses the influences of A/R value on unsteady performances of a double-entry turbocharger turbine. In the study, numerical simulation has been done by ANSYS CFX software, The turbine have three kinds of A/R values that change in order, and the three schemes has the same unsteady flow boundary conditions. The simulation results show that the unsteady turbine performances have the characteristics loops representing filling and emptying effects. And the unsteady performances of the three schemes have some regular differences. The mean unsteady turbine efficiency decreases with increasing A/R value in the involved range, but the overall entropy of the turbine in a pulse period has no significant differences.

In this paper, on the basis of multi -zone combustion modeling concept, a developed quasi-dimensional multi-zone model for emissions prediction of DI diesel engine is put forward. In the model, the fuel spray is divided into many zones. Each zone goes through such processes as fuel spray broken, droplet evaporation, air involvement, mixed air - fuel combustion, etc. The influence of spray touching the wall and the swirl are considered. The heat transfer formula from each zone to combustion chamber wall has been improved and the space distribution ununiformity of the diameter of fuel droplets has been considered. Based on the chemical equilibrium calculation, Zeldowich disequilibrium theory is used to predict the emission of NOx. For C, CO and HC, the kinetics reactions are adopted. In addition, an simplified model for rough prediction of particulate emission is provided.

The heat transfer and fluid flow in an air-to-air tube-bend intercooler are tested by an infrared imagine system and a hot-wire anemometer separately. The results show that: it is helpful to improve heat transfer performance of the intercooler by changing the corners with circular beads, selecting suitable tube thin and the plate thin between two hot air ducts, and adding some device at the inner of cooling boundary in the ducts.

An axially movable vane turbocharger has been modified based on the basic aerodynamic design principles, and good performance is obtained. The details of design and engine bench testing results of several vane variations are presented, and the most suitable assembly nozzle with two separate vanes is then developed. These have produced a simple design with a minimum number of the moving parts. Experimental data also show that the new turbocharger efficiently expands the effective torque band and get the low fuel consumption at a wide engine speed range.

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.