Development of an Integrated Virtual Engine Model to Simulate New Standard Testing Cycles

Martín, Javier Rodríguez; Arnau, Francisco José; Piqueras, Pedro; Auñón, Ángel

doi:10.4271/2018-01-1413

Cited by 31 publications

(37 citation statements)

References 35 publications

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“…The increasingly rigorous regulation on pollutants and CO 2 emissions have led to the World harmonized Light vehicles Test Procedure (WLTP), 3 which came into force in September 2017 in Euro 6d-Temp, which has more realistic testing conditions including extended ambient temperature ranges covering low temperature conditions. 4 This WLTC (World harmonized Light vehicles Test Cycle) is forcing the automotive industry to optimize different technologies such as engine rightsizing, turbocharging, direct injection, flexible valve actuation or aftertreatment systems that are standard solution for emissions reduction and fuel economy improvement of passenger cars and light-duty trucks. 4,5…”

Section: Introductionmentioning

confidence: 99%

“…4 This WLTC (World harmonized Light vehicles Test Cycle) is forcing the automotive industry to optimize different technologies such as engine rightsizing, turbocharging, direct injection, flexible valve actuation or aftertreatment systems that are standard solution for emissions reduction and fuel economy improvement of passenger cars and light-duty trucks. 4,5…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the energy balance during World harmonized Light vehicles Test Cycle in warmed and cold conditions using a Virtual Engine

Olmeda

Martín

Arnau

et al. 2019

International Journal of Engine Research

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In recent years, the interests on transient operation and real driving emissions have increased because of the global concern about environmental pollution that has led to new emissions regulation and new standard testing cycles. In this framework, it is mandatory to focus the engines research on the transient operation, where a Virtual Engine has been used to perform the global energy balance of a 1.6-L diesel engine during a World harmonized Light vehicles Test Cycle. Thus, the energy repartition of the chemical energy has been described with warmed engine and cold start conditions, analyzing in detail the mechanisms affecting the engine consumption. The first analysis focuses on the “delay” effect affecting the instantaneous energy balance due to the time lag between the in-cylinder processes and pipes: as a main conclusion, it is obtained that it leads to an apparent unbalance than can reach more than 10% of the cumulated fuel energy at the beginning of the cycle, becoming later negligible. Energy split analysis in cold starting World harmonized Light vehicles Test Cycle shows that in this condition the energy accumulation in the block is a key term at the beginning (about 50%) that diminishes its weight until about 10% at the end of the cycle. In warmed conditions, energy accumulation is negligible, but the heat transfer to coolant and oil are higher than in cold starting conditions (21% vs 28%). The lower values of the mean brake efficiency at the beginning of the World harmonized Light vehicles Test Cycle (only about 20%) is affected, especially in cold starting, by the higher mechanical losses due to the higher oil viscosity and the heat rejection from the gases. The friction plays an important role only during the first half of the cycle, with a percentage of about 65% of the total mechanical losses and 10% of the total fuel energy at the end of the World harmonized Light vehicles Test Cycle. However, at the end of the cycle, it does not affect dramatically the mean brake efficiency which is about 31% both in cold starting and warmed World harmonized Light vehicles Test Cycle.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of the energy balance during World harmonized Light vehicles Test Cycle in warmed and cold conditions using a Virtual Engine

Olmeda

Martín

Arnau

et al. 2019

International Journal of Engine Research

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“…As sketched in Figure 1, VEMOD deals with these purposes based on an integral engine modelling that covers the calculation of a set of key processes. Firstly, the air management is computed by means of a 1D gas dynamics model [20] which deals with flow properties transport along the intake and exhaust systems as well as the longand short-route EGR paths. Thus, specific sub-models are considered for the boosting system, i.e.…”

Section: Exhaust Aftertreatment System Lumped Modelmentioning

confidence: 99%

Lumped Approach for Flow-Through and Wall-Flow Monolithic Reactors Modelling for Real-Time Automotive Applications

Payri¹,

Arnau²,

Piqueras³

et al. 2018

SAE Technical Paper Series

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The increasingly restrictive legislation on pollutant emissions is involving new homologation procedures driven to be representative of real driving emissions. This context demands an update of the modelling tools leading to an accurate assessment of the engine and aftertreatment systems performance at the same time as these complex systems are understood as a single element. In addition, virtual engine models must retain the accuracy while reducing the computational effort to get closer to real-time computation. It makes them useful for pre-design and calibration but also potentially applicable to on-board diagnostics purposes. This paper responds to these requirements presenting a lumped modelling approach for the simulation of aftertreament systems. The basic principles of operation of flow-through and wall-flow monoliths are covered leading the focus to the modelling of gaseous emissions conversion efficiency and particulate matter abatement, i.e. filtration and regeneration processes. The model concept is completed with the solution of pressure drop and heat transfer processes. The lumped approach hypotheses and the solution of the governing equations for every submodel are detailed. While inertial pressure drop contributions are computed from the characteristic pressure drop coefficient, the porous medium effects in wall-flow monoliths are considered separately. Heat transfer sub-model applies a nodal approach to account for heat exchange and thermal inertia of the monolith substrate and the external canning. In wall-flow monoliths, the filtration and porous media properties are computed as a function of soot load applying a spherical packed bed approach. The soot oxidation mechanism including adsorption reactant phase is presented. Concerning gaseous emissions, the general scheme to solve the chemical species transport in the bulk gas and washcoat regions is also described. In particular, it is finally applied to the modelling of CO and HC abatement in a DOC and DPF brick. The model calibration steps against a set of steady-state in-engine experiments allowing separate certain phenomena are discussed. As a final step, the model performance is assessed against a transient test during which all modelled processes are taking place simultaneously under highly dynamic driving conditions. This test is simulated imposing different integration time-steps to demonstrate the model´s potential for real-time applications.

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“…VEMOD is an engine model which covers the calculation of several physical processes, as sketched in Figure 1. Air management is computed by means of a 1D gas dynamics model [1]. The model deals with flow properties transport along the intake and the exhaust systems as well as the high and low pressure EGR paths [25].…”

Section: Virtual Engine Model (Vemod)mentioning

confidence: 99%

“…Therefore, to thoroughly model engine performance under dynamic conditions a global, multi-domain approach is essential. With this in mind, a software called Virtual Engine Model (VEMOD) has been developed at CMT-Motores Térmicos [1]. This computational tool arises as a response to highly limiting requirements of emission standards imposed by new homologation procedures, closer to real-world driving conditions in terms of engine dynamic operation and ambient conditions (low temperature and altitude).…”

Section: Introductionmentioning

confidence: 99%

Development and Validation of a Submodel for Thermal Exchanges in the Hydraulic Circuits of a Global Engine Model

Broatch

Olmeda

Martín

et al. 2018

SAE Technical Paper Series

Self Cite

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To face the current challenges of the automotive industry, there is a need for computational models capable to simulate the engine behavior under low-temperature and low-pressure conditions. Internal combustion engines are complex and have interconnected systems where many processes take place and influence each other. Thus, a global approach to engine simulation is suitable to study the entire engine performance. The circuits that distribute the hydraulic fluids-liquid fuels, coolants and lubricants-are critical subsystems of the engine. This work presents a 0D model which was developed and set up to make possible the simulation of hydraulic circuits in a global engine model. The model is capable of simulating flow and pressure distributions as well as heat transfer processes in a circuit. After its development, the thermo-hydraulic model was implemented in a physical based engine model called Virtual Engine Model (VEMOD), which takes into account all the relevant relations among subsystems. In the present paper, the thermo-hydraulic model is described and then it is used to simulate oil and coolant circuits of a diesel engine. The objective of the work is to validate the model under steady-state and transient operation, with focus on the thermal evolution of oil and coolant. For validation under steady-state conditions, 22 operating points were measured and simulated, some of them in cold environment. In general, good agreement was obtained between simulation and experiments. Next, the WLTP driving cycle was simulated starting from warmed-up conditions and from ambient temperature. Results were compared with the experiment, showing that modeled trends were close to those experimentally measured. Thermal evolutions of oil and coolant were predicted with mean errors between 0.7ºC and 2.1ºC. In particular, the warm-up phase was satisfactorily modeled.

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Development of an Integrated Virtual Engine Model to Simulate New Standard Testing Cycles

Cited by 31 publications

References 35 publications

Analysis of the energy balance during World harmonized Light vehicles Test Cycle in warmed and cold conditions using a Virtual Engine

Analysis of the energy balance during World harmonized Light vehicles Test Cycle in warmed and cold conditions using a Virtual Engine

Lumped Approach for Flow-Through and Wall-Flow Monolithic Reactors Modelling for Real-Time Automotive Applications

Development and Validation of a Submodel for Thermal Exchanges in the Hydraulic Circuits of a Global Engine Model

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