Numerical Simulation Techniques for the Prediction of Fluid-Dynamics, Combustion and Performance in IC Engines Fuelled by CNG

Baratta, Mirko; Spessa, Ezio

doi:10.5772/25081

Cited by 4 publications

(3 citation statements)

References 44 publications

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“…The same sum must be superior to zero to avoid node H2 to take the contribution of the whole physical housing of the turbocharger, which must be necessarily distributed between the three housing nodes. (2) (3)…”

Section: Capacitances Determinationmentioning

confidence: 99%

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General Procedure for the Determination of Heat Transfer Properties in Small Automotive Turbochargers

Serrano

Olmeda

Arnau

et al. 2014

SAE Int. J. Engines

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These days many research efforts on internal combustion engines are centred on optimising turbocharger matching and performance on the engine. In the last years a number of studies have pointed out the strong effect on turbocharger behaviour of heat transfer phenomena. The main difficulty for taking into account these phenomena comes from the little information provided by turbocharger manufacturers. In this background, Original Engine Manufacturers (OEM) need general engineering tools able to provide reasonably precise results in predicting the mentioned heat transfer phenomena.Therefore, the purpose of this work is to provide a procedure, applicable to small automotive turbochargers, able to predict the heat transfer characteristics that can be used in a lumped 1D turbocharger heat transfer model. This model must be suitable to work coupled to whole-engine simulation codes (such as GT-Power or Ricardo WAVE) for being used in global engine models by the OEM. Moreover, the procedure must be capable to predict heat transfer effects using available data as external geometrical parameters of the turbocharger.To reach these several purposes, a description of the procedure to obtain correlations for heat transfer behaviour to be used in a lumped model is given. The procedure is based on several generalised correlations obtained from the evaluation of heat transfer properties of different turbochargers. The validity of the procedure is confirmed by simulations performed in GT-Power environment compared to experimental results both in a gas stand and in an engine test bench. The results of the validation show an acceptable level of accuracy using the proposed procedure. Furthermore, the advantages of the procedure are shown by comparing its results with the results of standard GT-Power simulations. In these last simulations only turbocharger maps are used without a turbocharger heat transfer model. Further analysis of these results evidences that the simple procedure of using general correlations for heat transfer properties in a lumped model is accurate enough to predict turbine outlet temperature much better than standard GT-Power model. This parameter is crucial for after treatment modelling and design as well as for two stage turbocharging.

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Section: Capacitances Determinationmentioning

confidence: 99%

“…Traditionally, turbochargers behaviour has been modelled neglecting heat transfer phenomena [1,2], especially when a whole-engine simulation is carried out [3,4]. However, in the last decade several authors claimed about the importance of considering heat transfer phenomena to generate improved models for turbocharger and engine modelling.…”

Section: Introductionmentioning

confidence: 99%

General Procedure for the Determination of Heat Transfer Properties in Small Automotive Turbochargers

Serrano

Olmeda

Arnau

et al. 2014

SAE Int. J. Engines

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“…Baratta et al studied deeply the 0D combustion models and 1D simulation applied to internal combustion engines in 2011. 14 In 2019 Korsunovs et al evaluated a zero-dimensional stochastic reactor modeling to predict NOx emissions. 15 Poubeau et al 16 developed a methodology and used the 1D and 3D modeling to study the benefits of thermal insulation in the combustion chamber, which was an issue previously studied, by modeling and experimentally, by Andruskiewicz et al 17,18 In 2019 Galindo et al examined numerous extrapolation methods to study off-design conditions of the compressor map for 0D and 1D engine simulations.…”

Section: Introductionmentioning

confidence: 99%

A study on the high pressure EGR transport and application to the dispersion among cylinders in automotive engines

Galindo

Climent

Garcia

et al. 2020

International Journal of Engine Research

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The objective of this study is to explore the limits of a one-dimensional model to predict the movement and mixing of the air and exhaust gases recirculation (EGR) flows in compact intake manifolds of recent automotive engines. In particular, the high pressure EGR loop configuration is evaluated in this study from the perspective of the EGR dispersion among cylinders. The experimental work includes the use of a fast CO2 tracking system that provides crank-angle resolved results in six locations of the intake manifold together with the acquisition of the time-averaged CO2 concentration in all the intake pipes (eight locations) to evaluate the EGR dispersion empirically. A specific system was developed to inject the EGR in three locations of the intake manifold in a flexible way to modify the dispersion. Up to 29 engine running conditions defined by engine speed, engine torque and EGR rate, spanning the entire engine map, including full load operation, were evaluated. A one-dimensional engine model was built to detect the limits in reproducing the EGR transport in the intake manifold and quantify the accuracy when predicting the dispersion among cylinders. The study concludes that the predicted EGR rate in the cylinders may differ up to 75% from the experimental measurement at low engine averaged EGR rate. The model prediction improves to differences lower than 40% in EGR rate per cylinder if the engine operating points with an EGR rate lower than 10% are excluded. In this situation, 80% of the predicted in-cylinder EGR rates have differences lower than 25% when compared to experiments.

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Development and validation of a radial turbine efficiency and mass flow model at design and off-design conditions

Serrano

Arnau

Dombrovsky

et al. 2016

Energy Conversion and Management

118

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ElsevierSerrano Cruz, JR.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Dombrovsky, A.; Tartoussi, H. (2016). Development and validation of a radial turbine efficiency and mass flow model at design and off-design conditions. Energy Abstract Turbine performance at extreme off-design conditions is growing in importance for properly computing turbocharged reciprocating internal combustion engines behaviour during urban driving conditions at current and future homologation cycles. In these cases, the turbine operates at very low flow rates and power outputs and at very high blade to jet speed ratios during transitory periods due to turbocharger wheel inertia and the high pulsation level of engine exhaust flow. This paper presents a physically based method that is able to extrapolate radial turbines reduced mass flow and adiabatic efficiency in blade speed ratio, turbine rotational speed and stator vanes position. The model uses a very narrow range of experimental data from turbine maps to fit the necessary coefficients. By using a special experimental turbocharger gas stand, experimental data have been obtained for extremely low turbine power outputs for the sake of model validation. Even if the data used for fitting only covers the turbine normal operation zone, the extrapolation model provides very good agreement with the experiments at very high blade speed ratio points; producing also good results when extrapolating in rotational speed and stator vanes position. RPerfect gas constant (Jkg −1 K −1 ) r Rotor radius (m) sd Standard deviation (−) 12 provided by manufacturers as a standard practice. Turbine maps are necessary 13 when using 1D or 0D modelling tools to predict the whole engine behaviour. In 14 1D modelling approach the one-dimensional unsteady non-homentropic mass, 15 momentum and energy conservation laws (Euler equations) are solved. Specific 16 source terms are used to simulate the friction and heat exchange in the pipes. 17 The 1D simulation codes make possible the calculation of gas dynamics engine 18 behaviour at low computational costs. Some engine components are modelled 19 4 with a 0D approach, using specific lumped parameter models or performance 20 maps. That is the case of cylinders, injectors, valves, compressors and turbines 21 which are coupled to the 1D computational domain as it is described in [4]. 22 For that reason, turbocharged ICE designers must rely on map extrapolation 23 tools when predicting engine performance outside of turbine design operative 24 conditions [5]. It is typical in pulsating flow conditions, requiring different mod-25 elling approaches similar to the proposed in [6], where meanline one-dimensional 26 models are discussed and in [7], where non-adiabatic pressure loss boundary con-27 dition is discussed. One-dimensional tools are also used in design process for 28 fast evaluation of turbine capabilities as in [8]. In [9] a Taylor series expansion 29 is used to develop a model able of predicting mass flow parameter of radial 30 turbines. 31 CFD models for turb...

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Numerical Simulation Techniques for the Prediction of Fluid-Dynamics, Combustion and Performance in IC Engines Fuelled by CNG

Cited by 4 publications

References 44 publications

General Procedure for the Determination of Heat Transfer Properties in Small Automotive Turbochargers

General Procedure for the Determination of Heat Transfer Properties in Small Automotive Turbochargers

A study on the high pressure EGR transport and application to the dispersion among cylinders in automotive engines

Development and validation of a radial turbine efficiency and mass flow model at design and off-design conditions

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