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A novel one-dimensional multiphase and multicomponent spray model - hereafter referred to as the Kattke-Weigand model - has been developed to predict the penetration length of both vapor and liquid gasoline sprays under flash-boiling conditions, such as superheated injections. Its formulation is based on mass and momentum equations for unsteady jets and is therefore capable of capturing dynamic effects. Experiments were conducted in a constant volume chamber using various ambient and fuel temperature conditions and a six-hole GDI injector with a separated jet. Macroscopic spray parameters were extracted from the measurements to verify the model's ability to predict both liquid and vapor penetration length and the corresponding spray angles. Apart from the separated jet of the injector used, the other five jets interact strongly with each other under flash boiling conditions, resulting in spray collapse, and thus affecting spray characteristics.

Although electricity is necessary for a country's economic development, many countries lack suitable grid infrastructure. Portable generators offer a consistent electric supply in the event of a blackout. Be-Rex B.V. develops and already assembled a revolutionary engine-generator prototype. It eliminates the use of camshafts, crankshafts and flywheels while integrating the generator parts into the same spherical housing. Thus, it constitutes a compact, lightweight and cost-efficient singular unit. There is no mechanical power output while the load of the engine is determined by the demanded load of the generator. The four combustion chambers are arranged in pairs on the north and south hemisphere and the magnets of the stator are placed circumferential at the equator of the spherical housing. The rotating disc and the joiner build the rotor of the generator. While developing the engine special emphasis has been put on its multi-fuel capability.

Ammonia, which is considered as an excellent hydrogen carrier, could potentially become a clean fuel for direct use in ICE. An experimental setup with a strongly modified inline four-cylinder (I4) heavy duty Diesel engine was used to study different combustion modes of ammonia in ICE. The fourth cylinder of that engine was operated in a monovalent mode using either OME or Diesel fuel. Its complete exhaust stream was fed into the first cylinder of the same engine, which was operated on a dual-fuel mode by utilizing ammonia port injection and OME or Diesel pilot injection to ignite the mixture. The fourth cylinder of the I4 heavy duty engine can be operated at conditions between idle and full load and at different stoichiometries (λ) to impact both the temperature and the oxygen concentration at the exhaust of that cylinder.

The starting point of the present work is a global model of NOx formation for stoichiometric and lean combustion of hydrocarbons developed on the basis of a single non-linear algebraic equation. The latter is the exact solution of a system of differential equations describing the main kinetic reaction schemes of NOx formation, because it’s been analytically derived. The NOx sub-model incorporates the well-established thermal (extended Zeldovich) and the N2O reaction paths, which are considered to be the most relevant NOx production paths under certain operating conditions in arbitrary engine application. Furthermore, the NOx sub-model proposed here relies on well-established and adopted mechanisms like the GRI-Mech 3.0 [25] and consequently requires no parameter adjustment.

In this work a quasi-dimensional multi-zone combustion diagnostic tool for homogeneous charge Spark Ignition (SI) engines is analytically developed for the evaluation of heat release, flame propagation, combustion velocities as well as engine-out NOx and CO emissions, based on in-cylinder pressure data analysis. The tool can be used to assess the effects of fuel, design and operating parameters on the SI engine combustion and NOx and CO emissions formation processes. Certain novel features are included in the presently developed combustion diagnostic tool. Firstly, combustion chambers of any shape and spark plug position can be considered due to an advanced model for the calculation of the geometric interaction between a spherically expanding flame and a general combustion chamber geometry.

In this work, a new CO emissions formation model is developed based on the dynamics of a representative pool of radicals in the post-flame combustion gases. The ultimate target is the derivation of a kinetics-based CO model, formulated by a single differential equation, that can run very fast in any engine diagnostic/post-processing tool which analyzes in-cylinder processes in the framework of big data acquired at the engine test bench or during engine operation in the field. Specific objectives in the development of the current model are (i) inclusion of the effect of engine operating conditions on the CO emissions formation mechanism, (ii) ease of implementation in any diagnostic code/platform, (iii) fast running times toward real-time capability, and (iv) robustness. The presently developed CO model consists of a single Ordinary Differential Equation (ODE) that can be solved analytically, without the need of a stiff chemical kinetics solver.

A new global NOx emissions formation model, formulated by a single analytically derived algebraic equation, is developed with relevance to post-flame gases. The model originates from subsets of detailed kinetic schemes for thermal and N2O pathway NO formation, needs no calibration and is quick to implement and run. Due to its simplicity, the model can be readily used in both 1D and 3D-CFD simulation codes, as well as for direct post-processing of engine test data. Characteristic timescales that describe the kinetic nature of the involved NO formation routes, when they evolve in the post-flame gases independently the one from another, are introduced incorporating kinetic information from all relevant elementary reactions.