Benchmarking a 2018 Toyota Camry 2.5-Liter Atkinson Cycle Engine with Cooled-EGR

Kargul, John; Stuhldreher, Mark; Barba, Daniel; Schenk, Charles; Bohac, Stanislav V.; McDonald, Joseph; Dekraker, Paul; Alden, J.W.

doi:10.4271/2019-01-0249

Cited by 34 publications

(15 citation statements)

References 17 publications

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“…To put this into a context with potential impact to fuel economy, the model results were utilized to construct brake efficiency maps as mentioned in the methodology section. The MMC brake efficiency map was overlaid onto that of a conventional naturally aspirated SI engine using the information from EPA’s benchmarking . In addition, to provide insights on how a difference in the load coverage for given fuels could influence fuel economy, a contour is added, which represents an approximate extent of conditions contributing significantly to the combined City and Highway Fuel Economy Tests .…”

Section: Resultsmentioning

confidence: 99%

“…These results are contingent on the choice of investigated conditions, namely, the CRs and engine speeds which have been tested. However, these conditions are reflective of the engine speeds which characteristically make up significant portions of federal test procedures, 31 and at which other fuel-saving technologies, such as cylinder deactivation, are active. 32 The CRs which were tested are reflective of those found in the market for high-performance and high-efficiency naturally aspirated engines.…”

Section: ■ Modeling Approachmentioning

confidence: 99%

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Octane Requirements of Lean Mixed-Mode Combustion in a Direct-Injection Spark-Ignition Engine

et al. 2022

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This study investigates the octane requirements of a hybrid flame propagation and controlled autoignition mode referred to as mixed-mode combustion (MMC), which allows for strong control over combustion parameters via a spark-initiated deflagration phase. Due to the throughput limitations associated with both experiments and 3-D computational fluid dynamics calculations, a hybrid 0-D and 1-D modeling methodology was developed, supported by experimental validation data. This modeling approach relied on 1-D, two-zone engine simulations to predict bulk in-cylinder thermodynamic conditions over a range of engine speeds, compression ratios, intake pressures, trapped residual levels, fueling rates, and spark timings. Those predictions were then transferred to a 0-D chemical kinetic model, which was used to evaluate the autoignition behavior of fuels when subjected to temperature–pressure trajectories of interest. Finally, the predicted autoignition phasings were screened relative to the progress of the modeled deflagration-based combustion in order to determine if an operating condition was feasible or infeasible due to knock or stability limits. The combined modeling and experimental results reveal that MMC has an octane requirement similar to modern stoichiometric spark-ignition engines in that fuels with high research octane number (RON) and high octane sensitivity (S) enable higher loads. Experimental trends with varying RON and S were well predicted by the model for 1000 and 1400 rpm, confirming its utility in identifying the compatibility of a fuel’s autoignition behavior with an engine configuration and operating strategy. However, the model was not effective in predicting (nor designed to predict) operability limits due to cycle-to-cycle variations, which experimentally inhibited operation of some fuels at 2000 rpm. Putting the operable limits and efficiency from MMC in the context of a state-of-the-art engine, the MMC showed superior efficiencies over the range investigated, demonstrating the potential to further improve fuel economy.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Modeling Approachmentioning

confidence: 99%

Octane Requirements of Lean Mixed-Mode Combustion in a Direct-Injection Spark-Ignition Engine

et al. 2022

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“…The choice of a valve train system, i.e., either a fixed camshaft or a fully variable valve train and its influence on the fuel consumption are investigated for both engine types. The model for the naturally aspirated engine is based on data obtained from measurements on a 2018 2.5 L Atkinson cycle engine with cooled exhaust gas recirculation [54]. The turbocharged engine is modeled with own data obtained from measurements on an engine test bench equipped with a 3.0 L direct-injected SI engine.…”

Section: Internal Combustion Engine Modelmentioning

confidence: 99%

Optimal Degree of Hybridization for Spark-Ignited Engines with Optional Variable Valve Timings

et al. 2021

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The electric hybridization of vehicles with an internal combustion engine is an effective measure to reduce CO2 emissions. However, the identification of the dimension and the sufficient complexity of the powertrain parts such as the engine, electric machine, and battery is not trivial. This paper investigates the influence of the technological advancement of an internal combustion engine and the sizing of all propulsion components on the optimal degree of hybridization and the corresponding fuel consumption reduction. Thus, a turbocharged and a naturally aspirated engine are both modeled with the additional option of either a fixed camshaft or a fully variable valve train. All models are based on data obtained from measurements on engine test benches. We apply dynamic programming to find the globally optimal operating strategy for the driving cycle chosen. Depending on the engine type, a reduction in fuel consumption by up to 32% is achieved with a degree of hybridization of 45%. Depending on the degree of hybridization, a fully variable valve train reduces the fuel consumption additionally by up to 9% and advances the optimal degree of hybridization to 50%. Furthermore, a sufficiently high degree of hybridization renders the gearbox obsolete, which permits simpler vehicle concepts to be derived. A degree of hybridization of 65% is found to be fuel optimal for a vehicle with a fixed transmission ratio. Its fuel economy diverges less than 4% from the optimal fuel economy of a hybrid electric vehicle equipped with a gearbox.

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“…Although such maps form the basis of simulation studies, it is very difficult to obtain them from the literature. There are excellent quality BSFC/thermal efficiency maps available for ICEs (e.g., [33]), including those supplied with LPG (e.g., [34]), but there are very few maps for the entire range extender, i.e., an ICE coupled with an electric generator (e.g., [35]) and not two separate maps combined together (e.g., [36]). Finally, there are no maps for LPG-supplied range extenders.…”

Section: Introductionmentioning

confidence: 99%

Empirical Study on the Efficiency of an LPG-Supplied Range Extender for Electric Vehicles

et al. 2019

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A range extender is an auxiliary power unit, usually consisting of an internal combustion engine and an electric generator, which is used to charge a battery of an electric vehicle in order to increase its range. This paper considers a range extender supplied with liquefied petroleum gas (LPG). The aim is to provide detailed data on thermal efficiency, brake specific fuel consumption (BSFC), and unit emission of carbon dioxide (CO 2 ) in a broad spectrum of range extender operating conditions defined by rotational speed and torque. The experimental investigation has been conducted using a laboratory test stand equipped with an energy dissipation system of adjustable resistance. Measurement results, including fuel flow rate, were processed using custom algorithm for generating maps, i.e., two-dimensional dependencies of the considered parameters on the rotational speed and torque. The maps obtained for LPG supply were compared with those for gasoline supply. The results demonstrated feasibility of LPG-supplied range extender. Its BSFC and thermal efficiency were at a comparable level to those obtained for gasoline supply, but with less CO 2 emission. The empirical data collected has been adopted in the simulation of extended-range electric vehicle in a driving cycle, showing the potential of utilizing the results of this study.Energies 2019, 12, 3528 2 of 23 ( Figure 1). Their principle of operation is same as that of a standard BEVs, with the only difference being that an additional ICE acts as an on-board generator (range extender) to recharge the battery [11]. EREVs operate exclusively as BEVs when battery energy is available and have full performance in electric mode (e.g., top speed, acceleration capability) [12]. This is possible owing to EREV's electric propulsion system and battery sized in such a way that the ICE is not required for vehicle operation as long as battery energy is available [12]. It is therefore preferable to move the vehicle with the use of an electric motor only, i.e., in "zero emission" driving mode, but at the same time, the user is not afraid of running out of battery energy, and so called "range anxiety" (the term was introduced in the late 1990s [13]) is alleviated.Energies 2019, 12, x FOR PEER REVIEW 2 of 25 being that an additional ICE acts as an on-board generator (range extender) to recharge the battery [11]. EREVs operate exclusively as BEVs when battery energy is available and have full performance in electric mode (e.g., top speed, acceleration capability) [12]. This is possible owing to EREV's electric propulsion system and battery sized in such a way that the ICE is not required for vehicle operation as long as battery energy is available [12]. It is therefore preferable to move the vehicle with the use of an electric motor only, i.e., in "zero emission" driving mode, but at the same time, the user is not afraid of running out of battery energy, and so called "range anxiety" (the term was introduced in the late 1990s [13]) is alleviated.

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Benchmarking a 2018 Toyota Camry 2.5-Liter Atkinson Cycle Engine with Cooled-EGR

Cited by 34 publications

References 17 publications

Octane Requirements of Lean Mixed-Mode Combustion in a Direct-Injection Spark-Ignition Engine

Octane Requirements of Lean Mixed-Mode Combustion in a Direct-Injection Spark-Ignition Engine

Optimal Degree of Hybridization for Spark-Ignited Engines with Optional Variable Valve Timings

Empirical Study on the Efficiency of an LPG-Supplied Range Extender for Electric Vehicles

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