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In modern vehicle air conditioning concepts, the temperatures at the outlets of the Heating Ventilation and Air Conditioning (HVAC) unit are controlled using temperature sensors in combination with an Automatic Climate Control (ACC) system. A novel coupled Proper Orthogonal Decomposition (POD) and Flow Resistance Network (FRN) model approach is proposed to accurately predict the temperatures at the outlets of a HVAC unit for real-time model based control. The integral enthalpy flow rates at the outlets, which result from a complex mixing process in the mixing chamber of the HVAC unit, are approximated by a linear combination of orthonormal POD modes. A FRN is established to compute the volume flow rates at the outlets. By combining the classical FRN with the POD model the weighting coefficients for the POD modes can be determined from the volume flow rates estimated by the network model.

Cabin heating and cooling loads of modern vehicles, notably electrically driven, represent a major portion of the overall vehicle energy consumption. Various concepts to reduce these loads have thus been proposed but quantitative experimental analysis or numerical predictions are scarcely available. Conventional 1D or zonal cabin models do not account adequately for strongly inhomogeneous cabin climate conditions. In this paper a new cabin model is presented, which delivers both temporally and spatially resolved data. The model uses a dynamic coupling algorithm including a CFD simulation of the cabin airflow, a model of the cabin structure and the detailed passenger Fiala Physiological Comfort (FPC) model.

In this project funded by the Bayerische Forschungsstiftung two fundamental investigations had been carried out: first a new N-rich liquid ammonia precursor solution based on guanidine salts had been completely characterized and secondly a new type of side-flow reactor for the controlled catalytic decomposition of aqueous NH₃ precursor to ammonia gas has been designed, applied and tested in a 3-liter passenger car diesel engine. Guanidine salts came into the focus due to the fact of a high nitrogen-content derivate of urea. Specially guanidinium formate has shown extraordinary solubility in water (more than 6 kg per 1 liter water at room temperature) and therefore a possible high ammonia potential per liter solution compared to the classical 32.5% aqueous urea solution (AUS32) standardized in ISO 22241 and known as DEF (diesel emission fluid), ARLA32 or AdBlue® .

The application of homogeneous charge compression ignition in engines requires the limitation of high pressure rise rates at high loads and ignition timing control. Both effects can be influenced by the addition of water: The cooling effect based on its high latent heat of vaporization can be used to control ignition timing. Too early heat release at high compression ratios can be retarded towards TDC. Pressure rise rates can be reduced by inhomogeneous cooling and the dilution of the charge by steam. The paper discusses the effects of Diesel-water emulsions. The results are compared to the separate direct injection of fuel and water. The experiments were carried out on a rapid compression and expansion machine. Optical measurements were conducted using the shadowgraph technique in order to visualize spray penetration as well as combustion in the same cycle. A heat release analysis was performed on basis of the pressure indication. Gaseous emissions were electrochemically measured.

This paper discusses a new kind of diesel engine with tumble charge motion, pent-roof combustion chamber and piston with pot recess. At the Robert Bosch GmbH, a conventional single-cylinder test engine and an identical optical access engine were built up to study this new engine concept. In this paper, a first attempt to run homogeneous diesel combustion on this engine is presented. A strategy consisting of three operating points with two to four injections was used. These operating points were first run on the conventional test engine and after that studied on the optical access engine with the same boundary conditions. The information of the image data of the optical access engine was then related to the emission results of the conventional test engine.