A neuro-fuzzy based combustion sensor for the control of optimal engine combustion efficiency

Modern and advanced control systems for internal combustion engines require accurate feedback information from the combustion chamber. Whereas the in-cylinder pressure sensor provides this information through its close thermodynamic ties with the combustion process, drawbacks in its implementation push research towards other non-intrusive sensing methods. This paper suggests alternative methods of combustion phasing detection relying on measured angular crankshaft speed. Method developed, achieves sensing of angular position of the 50% of mass fraction burned (MFB50) through two steps: calculation of, so called, synthetic torque and its non-linear transformation to a combustion feature estimator through local model. In order to calibrate both parts of this virtual combustion sensor, parameters of a high-fidelity crankshaft dynamic model are identified, and the linear neuro-fuzzy based model is trained with extensive experimentally collected data set. Created virtual MFB50 sensor, demonstrated its performance, on a large test data set comprised of 70% of gathered data

Possibilities to identify engine combustion model parameters by analysis of the instantaneous crankshaft angular speed

In this paper, novel method for obtaining information about combustion process in individual cylinders of a multi-cylinder spark ignition engine based on instantaneous crankshaft angular velocity is presented. The method is based on robust box constrained Levenberg-Marquardt minimization of non-linear least squares given for measured and simulated instantaneous crankshaft angular speed which is determined from the solution of the engine dynamics torque balance equation. Combination of in-house developed comprehensive zero-dimensional two-zone spark ignition engine combustion model and analytical friction loss model in angular domain have been applied to provide sensitivity and error analysis regarding Wiebe combustion model parameters, heat transfer coefficient, and compression ratio. The analysis is employed to evaluate the basic starting assumption and possibility to provide reliable combustion analysis based on instantaneous engine crankshaft angular speed

Possibilities to identify engine combustion model parameters by analysis of the instantaneous crankshaft angular speed

In this paper, novel method for obtaining information about combustion process in individual cylinders of a multi-cylinder spark ignition engine based on instantaneous crankshaft angular velocity is presented. The method is based on robust box constrained Levenberg-Marquardt minimization of non-linear least squares given for measured and simulated instantaneous crankshaft angular speed which is determined from the solution of the engine dynamics torque balance equation. Combination of in-house developed comprehensive zero-dimensional two-zone spark ignition engine combustion model and analytical friction loss model in angular domain have been applied to provide sensitivity and error analysis regarding Wiebe combustion model parameters, heat transfer coefficient, and compression ratio. The analysis is employed to evaluate the basic starting assumption and possibility to provide reliable combustion analysis based on instantaneous engine crankshaft angular speed

The characteristics of combustion process of diesel engine using vegetable oil methyl esters

Biodiesel is one of the promising renewable, alternative, and environmentally friendly biofuels that can be used in Diesel engine with little or no modification in the engine. The present paper investigates the combustion characteristics of single cylinder, naturally aspirated, air cooled, Diesel engine fueled with pure (100%) methyl ester of rapeseed oil, comparing to the corresponding characteristics when it was driven by diesel fuel. Combustion process analysis for both fuels was done at constant engine speed and at two load levels corresponding to the mean effective pressure of three and six bar. It was also concluded that the test engine can operate without problems, both with that fuel and with a lot of other biofuels and their mixtures that were used during long laboratory research

The characteristics of combustion process of diesel engine using vegetable oil methyl esters

Biodiesel is one of the promising renewable, alternative, and environmentally friendly biofuels that can be used in Diesel engine with little or no modification in the engine. The present paper investigates the combustion characteristics of single cylinder, naturally aspirated, air cooled, Diesel engine fueled with pure (100%) methyl ester of rapeseed oil, comparing to the corresponding characteristics when it was driven by diesel fuel. Combustion process analysis for both fuels was done at constant engine speed and at two load levels corresponding to the mean effective pressure of three and six bar. It was also concluded that the test engine can operate without problems, both with that fuel and with a lot of other biofuels and their mixtures that were used during long laboratory research

Energetic and Ecological Aspects of the Application of Electric Drive Vehicles in Serbia

This paper considers the analysis of energetic and environmental aspects of electric drive vehicles application in Serbia. The analysis implies real conditions of road transport and electricity production in our country and evaluates the estimation of energy consumption and CO2 emission (Well-to-Wheel), under the assumption of hypothetical transition from classic internal combustion (IC) engine to pure electric drive of vehicles. For this purpose the real estimations of IC engines efficiency under the road conditions of operation and the global efficiency of electric drive system (electricity production, transmission network, battery and electric motor) were necessary. The results show that in the case of present reality of electricity production from coal (lignite), CO2 emission would be even higher. However, under the assumption of significantly more efficient electricity production (for example using combine cycle of gas turbine – CCGT), CO2 emission would be decreased. In this paper some experimental data of city bus fuel consumption and efficiency measurements are also presented

The effect of combustion chamber geometry layout on combustion and emission

In this paper some results concerning the combined effect of the fumble flow and combustion chamber geometry layout variations on flame front shape and its propagation through homogenous mixture of isooctane and air are presented Spatial distributions of NO in different combustion chamber geometries are presented as well. The basic combustion chamber geometry layout considered consists of the flat head with two vertical valves and a cylindrical bowl subjected to variations of depth and squish area. All results presented were obtained by dint of multidimensional modeling of reactive flows in arbitrary geometry with moving objects and boundaries with modified KIVA3 and KIVA3 V source codes. Two additional computer codes were applied to generate boundary conditions for KIVA3 V calculations with moving valves. The AVL TYCON code was used for the calculation of valve lift profiles, and A VL BOOST code was used for the calculation of relevant data set in the valve regions. Different combustion chamber geometry layouts generate different levels of squish, and the combustion effects in essence depend on the interaction of that flow with tumble. It was found that for particular combustion chamber shapes with different diameter/depth aspect ratios entirely different flame front shapes and propagation velocities were encountered primarily due to variations of fluid flow patterns in the vicinity of top dead center

Neural Networks Models Usage in Methods for Combustion Process Information Extraction in IC Engines

The In-cylinder pressure profile contains valuable information on the combustion process and its availability is greatly desirable in closed loop IC Engine control systems. The low lifetime and high costs of the currently available sensors are still preventing high-volume production of in-cylinder based engine control system. This paper deals with the potentials of Artificial Neural Networks (ANN) and their application in combustion features extraction, based solely on the crankshaft angular speed measurements. The focus of this paper is put on two concepts of ANN, based on a radial basis function (RBF) and a local linear Neuro-fuzzy models (LLNFM) and their applicability in virtual sensing of crucial combustion process parameters. Training and validation of the suggested ANN models is based on comprehensive engine test bed data set

Some Subtleties Concerning Fluid Flow and Turbulence Modeling in 4-Valve Engines

In this paper some results concerning the structure and evolution of fluid flow pattern during induction and compression in 4- valve engines with tilted valves were presented. Results were obtained by dint of multidimensional modeling of non-reactive flows in arbitrary geometry with moving boundaries. During induction fluid flow pattern was characterized with organized tumble motion followed by small but clearly legible deterioration in the vicinity of the bottom dead center. During compression the fluid flow pattern is entirely three-dimensional and fully controlled by vortex motion located in the central part of the chamber. In order to annihilate negative effects of tumble deterioration and to enhance swirling motion one of the intake valves was deactivated. Some positive and negative effects of such attempt were elucidated. The effect of turbulence model alteration in the case of excessive macro flows was tackled as well. Namely, some results obtained with eddy-viscosity model i. e. standard k-epsilon model were compared with results obtained with k-xi-f model of turbulence in domain of 4-valve engine in-cylinder flow. Some interesting results emerged rendering impetus for further quest in the near future

Model based approach in Yamaha R6 Formula Student Engine control parameters optimization

An involvement of the Internal Combustion Engines Department in the support activities to the University of Belgrade Formula Student team provided an opportunity to conduct some tests and research in the field of the engine control parameters optimization on a specific racing class engine –Yamaha YZF-R6s. The main goal of this research was getting optimal look-up tables for ignition timing and fuelling in order to obtain maximal performance in terms of effective torque and power of the air-flow restricted version of the engine, used in Formula Student competition vehicle. In order to improve accuracy and provide more detailed calibration data a model based approach is suggested with a detailed 1D thermodynamic model as a basis for additional testing point simulation. The method developed, provides a mean for model calibration to be based solely on data available from the limited number of measured engine effective parameters. This approach shows that a lack of test point data, due to test bench equipment limitations, can be successfully overcomed in engine optimisation process by using model based approach. Furthermore, the method used, demonstrated a capability of identifying combustion process parameters without in-cylinder pressure measurements and analysis