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The flow produced by an experimental high-swirl intake port was studied by several techniques. These included measurements of flow rate and swirl as a function of valve lift on a steady state bench rig, hot-wire measurements of flow issuing from the valve, and flow visualization in water and air. By applying these techniques together to a single port, a body of data was generated which is presented as an addition to what is known about intake port flows and swirl generation. Data include flow and swirl coefficients, information on the effects of valve offset and port orientation angle, swirl generation by velocity non-uniformity around the valve, swirl decay in the rig due to air friction on the walls, and forward/backward flow coefficients. The definition of the appropriate dimensionless parameters for port flow characterization is also discussed.

A combined experimental/analytical study was made of a 2.2ℓ production engine. The objective was to characterize the performance of the engine and the pressure wave dynamics in its manifolds, and to compare the data/predictions obtained using an engine simulation program. Description of the computer program is given, providing an overview of its capabilities and of the models it contains. The data was obtained at wide open throttle, at four engine speeds from 1600 rpm to 4800 rpm. The comparisons showed the ability of the simulation to predict the major features of the wave dynamics, including the amplitude, frequency and phasing of the waves, and their tuning and de-tuning at the various engine speeds.

The use of engine simulation is rapidly increasing throughout the engine industry. In the present paper, the major contributing factors which drive this trend are discussed. These include the increasing sophistication of the simulations, both in the area of high accuracy and in user-friendliness. Also, the decreasing cost of engineering computer workstations places them on the desktop of engineers and makes them readily available. Furthermore, the steadily rising computer processing power now provides the response needed in the engine development environment. The advances seen in simulations now open a new area for their application--as a tool fully complementary to test and measurement in a “concurrent test and simulation” process. The wide-ranging benefits and opportunities offered by the process are described in detail.

An increasing emphasis is being placed in the vehicle development process on transient operation of engines and vehicles, and of engine/vehicle integration, because of their importance to fuel economy and emissions. Simulations play a large role in this process, complementing the more usual test-oriented hardware development process. This has fueled the development and continued evolution of advanced engine and powertrain simulation tools which can be utilized for this purpose. This paper describes a new tool developed for applications to transient engine and powertrain design and optimization. It contains a detailed engine simulation, specifically focused on transient engine processes, which includes detailed models of engine breathing (with turbocharging), combustion, emissions and thermal warm-up of components. Further, it contains a powertrain and vehicle dynamic simulation.