PRÄZISIONS-ORTSBESTIMMUNGEN IN WISSENSCHAFTLICHEN GERÄTEBAUVERFAHREN UND GRENZEN

The paper gives a survey of the precision position measurement procedures of scalelines and of the edge of the body, with the accuracy less than 0,5 qm. Shows the paper also the need of the unambiguos definition of the position itself. All of the methods which are based on the photometrical position measurement are working with error only, because of the illumination distribution defined sensorsignal. The author uses vector and tensor calculations for investigation of geometrical error of measuring apparatus

Analysis of the effects of wall temperature swing on reciprocating internal combustion engine processes

[EN] A thermal wall temperature swing model was built to capture the transient effects of various material properties and coating layers on the intra-cycle wall temperature of an internal combustion engine. This model was used with a thermodynamic engine simulation to predict and analyze the effects of different types of in-cylinder insulation on engine performance. Coatings that allow the surface temperature to swing in response to the gas' cyclical heat flux enable approximately 1/3 of the energy that was prevented from leaving the gas during expansion to be recovered while improving volumetric efficiency. Reductions in compression work due to better volumetric efficiency and less heat transfer from the walls to the gas accounted for half of the improvements, while additional work extraction during combustion and expansion accounted for the other half. As load increases, the temperature swing and benefits derived from it also increase. NSFC improvements of 0.5% to 1% were seen with a highly swinging coating in the throttled regime for a realistic engine geometry and coating area, up to 2.5% at high loadsAndruskiewicz, P.; Najt, P.; Durrett, R.; Biesboer, S.; Schaedler, T.; Payri, R. (2018). Analysis of the effects of wall temperature swing on reciprocating internal combustion engine processes. International Journal of Engine Research. 19(4):461-473. https://doi.org/10.1177/1468087417717903S461473194Ramesh Kumar, C., & Nagarajan, G. (2012). Performance and emission characteristics of a low heat rejection spark ignited engine fuelled with E20. Journal of Mechanical Science and Technology, 26(4), 1241-1250. doi:10.1007/s12206-012-0206-0Hoffman, M. A., Lawler, B. J., Güralp, O. A., Najt, P. M., & Filipi, Z. S. (2014). The impact of a magnesium zirconate thermal barrier coating on homogeneous charge compression ignition operational variability and the formation of combustion chamber deposits. International Journal of Engine Research, 16(8), 968-981. doi:10.1177/146808741456127

An adapted heat transfer model for engines with tumble motion

In the last years, a growing interest about increasing the engine efficiency has led to the development of new engine technologies. The accurate determination of the heat transfer across the combustion chamber walls is highly relevant to perform a valid thermal balance while evaluating the potential of new engine concepts. Several works dealing with heat transfer correlations that consider the swirl motion are found in the literature; however, there is a lack of works dealing with heat transfer correlations which take into account the effect of the tumble movement. In this work, a new heat transfer model accounting for the tumble motion is presented. A two stroke HSDI Diesel engine with high tumble and no swirl is used to perform the theoretical study, the model development and its final calibration. Initially, a theoretical analysis of the gas movement phenomena is carried out based on CFD results and then, a model is developed and calibrated based on a skip-fire testing technique. Finally, a sensitivity study focused on evaluating the model robustness is performed. The results confirm an average RMSE reduction of 70% with respect to the Woschni model, being this consistent improvement qualitatively evidenced in the instantaneous heat transfer evolutionThe support of the Spanish Ministry of Economy and Competitiveness (TRA2013-41348-R) is greatly acknowledged.Olmeda González, PC.; Martín Díaz, J.; Novella Rosa, R.; Carreño, R. (2015). An adapted heat transfer model for engines with tumble motion. Applied Energy. 158:190-202. https://doi.org/10.1016/j.apenergy.2015.08.051S19020215

Semiempirical in-cylinder pressure based model for NOx prediction oriented to control applications

This work describes the development of a fast NO X predictive model oriented to engine control in diesel engines. The in-cylinder pressure is the only instantaneous input signal required, along with several mean variables that are available in the ECU during normal engine operation. The proposed model is based on the instantaneous evolution of the heat release rate and the adiabatic flame temperature (both obtained among other parameters from the in-cylinder pressure evolution). Corrections for considering the NO X reduction due to the re-burning mechanism are also included. Finally, the model is used for providing a model-based correction of tabulated values for the NO X emission at the reference conditions. The model exhibits a good behaviour when varying exhaust gas recirculation rate, boost pressure and intake temperature, while changes in the engine speed and injection settings are considered in the tabulated values. Concerning the calculation time, the model is optimised by proposing simplified sub-models to calculate the heat release and the adiabatic flame temperature. The final result is suitable for real time applications since it takes less than a cycle to complete the NO X prediction.Guardiola García, C.; López Sánchez, JJ.; Martín Díaz, J.; García Sarmiento, D. (2011). Semiempirical in-cylinder pressure based model for NOx prediction oriented to control applications. Applied Thermal Engineering. 31(16):3275-3286. doi:10.1016/j.applthermaleng.2011.05.048S32753286311

Experiments on the influence of intake conditions on local instantaneous heat flux in reciprocating internal combustion engines

[EN] The present study tries to be a contribution for the development of more precise theoretical models for predicting the dissipation of heat through the combustion chamber walls of reciprocating (internal combustion) IC engines. A fast response thermocouple was embedded in the combustion chamber of a single cylinder engine to measure instantaneous wall temperatures. The heat flux was obtained by solving the one-dimensional transient energy equation with transient boundary conditions using the Fast Fourier Transform. The engine was tested under different operating conditions to evaluate the sensitivity of the measurement procedure to variations of three relevant combustion parameters: injection pressure, air temperature and oxygen concentration at the intake. The local heat flux obtained was compared with other relevant parameters that characterize the thermal behaviour of engines, showing, in most of the cases, correlation among them. The results showed that the instantaneous heat flux through the walls and hence the local wall temperatures are strongly affected by the ignition delay and the start of combustion. © 2010 Elsevier Ltd.Desantes, J.; Torregrosa, AJ.; Broatch, A.; Olmeda González, PC. (2011). Experiments on the influence of intake conditions on local instantaneous heat flux in reciprocating internal combustion engines. Energy. 36(1):60-69. doi:10.1016/j.energy.2010.11.011S606936

Optimal heat release shaping in a reactivity controlled compression ignition (RCCI) engine

[EN] The present paper addresses the optimal heat release (HR) law in a single cylinder engine operated under reactivity controlled compression ignition (RCCI) combustion mode to minimise the indicated specific fuel consumption (ISFC) subject to different constraints including pressure related limits (maximum cylinder pressure and maximum cylinder pressure gradient). With this aim, a 0-dimensional (0D) engine combustion model has been identified with experimental data. Then, the optimal control problem of minimising the ISFC of the engine at different operating conditions of the engine operating map has been stated and analytically solved. To evaluate the method viability a data-driven model is developed to obtain the control actions (gasoline fraction) leading to the calculated optimal HR, more precisely to the optimal ratio between premixed and diffusive combustion. The experimental results obtained with such controls and the differences with the optimal HR are finally explained and discussed.This work was supported by Ministerio de Economía y Competitividad through Project TRA2016-78717-R.Guardiola, C.; Plá Moreno, B.; García Martínez, A.; Boronat-Colomer, V. (2017). Optimal heat release shaping in a reactivity controlled compression ignition (RCCI) engine. Control Theory and Technology. 15(2):117-128. https://doi.org/10.1007/s11768-017-6155-5S117128152F. Payri, J. M. Luján, C. Guardiola, et al. A challenging future for the IC engine: New technologies and the control role. Oil & Gas Science and Technology–Revue D IFP Energies Nouvelles, 2015, 70(1): 15–30.H. Yanagihara, Y. Sato, J. Minuta. A simultaneous reduction in NOx and soot in diesel engines under a new combustion system (Uniform Bulky Combustion System–UNIBUS). Proceedings of the 17th international Vienna Motor Symposium, Vienna, 1996: 303–314.D. A. Splitter, M. L. Wissink, T. L. Hendricks, et al. Comparison of RCCI, HCCI, and CDC operation from low to full load. THIESEL 2012 conference on thermo-and fluid dynamic processes in direct injection engines. Valencia, 2012.J. Benajes, J. V. Pastor, A. García, et al. The potential of RCCI concept to meet EURO VI NOx limitation and ultra-low soot emissions in a heavy-duty engine over the whole engine map. Fuel, 2015, 159(1): 952–961.J. Benajes, A. García, J. Monsalve-Serrano, et al. An assessment of the dual-mode reactivity controlled compression ignition/conventional diesel combustion capabilities in a EURO VI medium-duty diesel engine fueled with an intermediate ethanol-gasoline blend and biodiesel. Energy Conversion and Management, 2016, 123(1): 381–391.S. Molina, A. García, J. M. Pastor, et al. Operating range extension of RCCI combustion concept from low to full load in a heavy-duty engine. Applied Energy, 2015, 143: 211–227.D. A. Splitter, R. D. Reitz. Fuel reactivity effects on the efficiency and operational window of dual-fuel compression ignition engines. Fuel, 2014, 118(5): 163–175.J. Benajes, S. Molina, A. García, et al. Effects of low reactivity fuel characteristics and blending ratio on low load RCCI (reactivity controlled compression ignition) performance and emissions in a heavy-duty diesel engine. Energy, 2015, 90: 1261–1271.J. Benajes, S. Molina, A. García, et al. An investigation on RCCI combustion in a heavy duty diesel engine using incylinder blending of diesel and gasoline fuels. Applied Thermal Engineering, 2014, 63(1): 66–76.J. Li, W. M. Yang, H. An, et al. Numerical investigation on the effect of reactivity gradient in an RCCI engine fueled with gasoline and diesel. Energy Conversion and Management, 2015, 92(1): 342–352.J. Benajes, S. Molina, A. García, et al. Effects of direct injection timing and blending ratio on RCCI combustion with different low reactivity fuels. Energy Conversion and Management, 2015, 99(1): 193–209.J. Benajes, J. V. Pastor, A. García, et al. A RCCI operational limits assessment in a medium duty compression ignition engine using an adapted compression ratio. Energy Conversion and Management, 2016, 126(1): 497–508.F. Zurbriggen, T. Ott, C. Onder, et al. Optimal control of the heat release rate of an internal combustion engine with pressure gradient, maximum pressure, and knock constraints. Journal of Dynamic Systems, Measurement, and Control, 2014, 136(6): DOI 10.1115/1.4027592.L. Eriksson, M. Sivertsson. Computing optimal heat release rates in combustion engines. SAE International Journal of Engines, 2015, 8(3): 1069–1079.L. Eriksson, M. Sivertsson. Calculation of optimal heat release rates under constrained conditions. SAE International Journal of Engines, 2016, 9(2): 1143–1162.Y. Zhang, T. Shen. Model based combustion phase optimization in SI engines: Variational analysis and spark advance determination. IFAC-PapersOnLine, 2016, 49(11): 679–684.F. Payri, P. Olmeda, J. Martín, et al. A new tool to perform global energy balances in DI diesel engines. SAE International Journal of Engines, 2014, 7(7): 43–59.S. Yu, M. Zheng. Ethanol-diesel premixed charge compression ignition to achieve clean combustion under high loads. Proceedings of the Institution of Mechanical Engineers–Part D: Journal of Automobile Engineering, 2016, 30(4): 527–541.D. Klos, D. Janecek, S. Kokjohn. Investigation of the combustion instability-NOx tradeoff in a dual fuel reactivity controlled compression ignition (RCCI) engine. SAE International Journal of Engines, 2015, 8(2): 821–830.G. Woschni. A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine. SAE Technical Paper. 1967: DOI 10.4271/670931.C. Guardiola, J. López, J. Martín, et al. Semi-empirical in-cylinder pressure based model for NOx prediction oriented to control applications. Applied Thermal Engineering, 2011, 31(16): 3275–3286.C. Guardiola, J. Martín, B. Pla, et al. Cycle by cycle NOx model for diesel engine control. Applied Thermal Engineering, 2017, 110: 1011–1020.J. M. Desantes, J. J. López, P. Redón, et al. Evaluation of the Thermal NO formation mechanism under low temperature diesel combustion conditions. International Journal of Engine Research, 2012, 13(6): 531–539.O. Sundstrm, L. Guzzella. A generic dynamic programming Matlab function. IEEE International Conference on Control Applications/International Symposium on Intelligent Control, St Petersburg: IEEE, 2009: 1625–1630.J. Benajes, A. García, J. M. Pastor, et al. Effects of piston bowl geometry on reactivity controlled compression ignition heat transfer and combustion losses at different engine loads. Fuel, 2016, 98(1): 64–77.J. Benajes, J. V. Pastor, A. García, et al. An experimental investigation on the influence of piston bowl geometry on RCCI performance and emissions in a heavy-duty engine. Energy Conversion and Management, 2015, 103: 1019–1031.J. M. Desantes, J. Benajes, A. García, et al. The role of the incylinder gas temperature and oxygen concentration over low load RCCI combustion efficiency. Energy, 2014, 78(SI): 854–868

A tool for predicting the thermal performance of a diesel engine

This paper presents a thermal network model for the simulation of the transient response of diesel engines. The model was adjusted by using experimental data from a completely instrumented engine run under steady-state and transient conditions. Comparisons between measured and predicted material temperatures over a wide range of engine running conditions show a mean error of 7◦C. The model was then used to predict the thermal behavior of a different engine. Model results were checked against oil and coolant temperatures measured during engine warm-up at constant speed and load, and on a New European Driving Cycle. Results show that the model predicts these temperatures with a maximum error of 3◦C.Torregrosa, AJ.; Olmeda González, PC.; Martín Díaz, J.; Romero Piedrahita, CA. (2011). A tool for predicting the thermal performance of a diesel engine. Heat Transfer Engineering. 32(10):891-904. doi:10.1080/01457632.2011.548639S891904321