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Ultra-Downsizing (UD) was introduced as an even higher level of downsizing for Internal Combustion Engines ICEs, see [2] SAE 2015-01-1252. The introduction of Ultra Downsizing (UD) aims to enhance the power, efficiency, and sustainability of ICEs while maintaining the thermal and mechanical strain within acceptable limits. The following approaches are utilized: 1 True Atkinson Cycles are implemented utilizing an asymmetrical crank mechanism called Variable Compression and Stroke Ratios (VCSR). This mechanism allows for extended expansion stroke and continuous adjustment of the Volumetric Compression Ratio (VCR). 2 Unrestricted two or more stage high-pressure turbocharging and intensive intercooling: This setup enables more complete filling of the cylinder and reduces the compression work on the piston, resulting in higher specific power and efficiency. 3 The new Load Control (LC) approach is based to continuous VCR adjustment.

The downsizing of Internal Combustion Engines (ICE) is already recognized as a very suitable method for the concurrent enhancement of Indicated Fuel Conversion Efficiency (IFCE) and the lowering of CO2 and NOx emissions. In this report, ultra-downsizing is introduced as an even higher stage of development of ICE. Ultra-downsizing will be implemented here by means of real Atkinson cycles using asymmetrical crank mechanisms, combined with multi-stage high-pressure turbocharging and very intensive intercooling. This will allow an increase of ICE performance while keeping the thermal and mechanical strain strength of engine components within the current usual limits.

The downsizing of internal combustion engines (ICE) is already recognized as a very suitable method for the concurrent enhancement of indicated fuel conversion efficiency (IFCE) and the lowering of CO₂ and NOx emissions. In this report, ultra-downsizing is introduced as an even higher stage of development of ICE. Ultra-downsizing will be implemented here by means of real Atkinson cycles using asymmetrical crank mechanisms, combined with multi-stage high-pressure turbocharging and very intensive intercooling. This will allow an increase of ICE performance while keeping the thermal and mechanical strain strength of engine components within the current usual limits.

Most recent implementations of the Atkinson cycle are not ideal from the point of view of thermal conversion efficiency ( TCE ). For example, Toyota has put a gasoline engine in its Prius II which should achieve high efficiency by using a modified Atkinson cycle based on variable intake valve timing management. Firstly, this implementation of the Atkinson cycle is not the ideal solution because some of the air is first sucked from the intake manifold into the cylinder and subsequently returned back there. Consequently, the oscillating air stream reduces the thermal conversion efficiency of this cycle to a considerable extent. Secondly, this implementation of the Atkinson cycle only reaches low levels of indicated mean pressure ( IMEP ) and, thirdly, it is not suitable for part load engine operating points ( EOP ) because of the lower TCE.

The paper focuses on a system and an appropriate controller concept for advanced air management of a turbo-charged passenger car diesel engine. The proposed air management system consists of a VTG turbocharger and two separate Exhaust Gas Recirculation (EGR) loops, a cooled or non-cooled high-pressure EGR (HP EGR) and a cooled low-pressure EGR (LP EGR) loop. In the LP EGR loop, the exhaust gas leaving the particulate filter is mixed with fresh air just in front of the compressor inlet. A main model (MM) was created in Simulink to design a Nonlinear Model-based Predictive Controller (NMPC). This model is mainly founded on physical equations, allowing easy adaptation to various systems. MM is a detailed model which was developed first and which is also used for software-in-the-loop (SIL) tests of the controller with the simulated engine.

The present paper focuses on a system and an appropriate controller concept for an advanced air management system of a turbocharged passenger car diesel engine. The proposed air management system consists of a VTG turbocharger, two separate EGR loops, a non-cooled high-pressure EGR and a cooled low-pressure EGR loop. In the low pressure EGR loop, the exhaust gas leaving the particulate filter is mixed with fresh air just in front of the compressor inlet. The first step consisted of developing a sensor and actuator concept. Prior to conducting engine tests on this system, GT power simulations were performed. Additionally, a MATLAB/Simulink model was created to design a model-based predictive controller. This model is mainly founded on physical equations, allowing for easy adaptation to various systems. At the beginning of the engine test stage, stationary measurements were conducted to examine the influence of variations of the EGR rate, boost pressure, fresh air mass, etc.

So far the simulation of the gas exchange, air/fuel mixture formation and burning processes in ICE was usually done, for cost reasons, by a combination of 1D models for the intake and exhaust manifold and 3D models for the cylinder. In order to implement the modeling of the pipe flow more exactly, and also economically at the same time, a new method is presented here, called the quasi-3D method. After the presentation of the theoretical basis and the detailed description of the modeling technique, the quasi 3D method for one-cylinder research engine is applied. The simulation results of this application are compared with pressure measurements, followed by an evaluation and discussion of their accuracy.

For ECU (Electronic Control Unit) development of LuK Electronic Clutch Management a hardware-in-the-loop application was generated from an existing off-line simulation environment. The development process, the HIL-structure, models, problems in implementing real-time-models, evaluation of models and comparison of numerical integration methods are described.

The use of the finite elements (FES) method for the computation of unsteady gas flow through the intake and exhaust pipes of a multi-cylinder engine set forth by the authors at the Congress of CIMAC’87 has been further developed by adapting a model with hybrid FEs; the model is based on the continuity-discontinuity duality. The state parameters of gases in a finite element (FE) have been broken into 1) field variables and 2) variables independent of spatial coordinates; the former allow continuity conditions in the knots whereas the latter do not; 3) compound variables. Gas state along the intake and exhaust lay-out has been defined as a system of four differential equations with partial derivatives of hyperbolic type which consider the fluid as compressible, viscous, in unsteady flow, with varying composition throughout its lay-outs.