Computational Fluid Dynamics Investigation on Multiple Injector Concepts at Different Swirl Ratios in a Heavy Duty Engine

Nyrenstedt, Gustav; Houidi, Moez Ben; Babayev, Rafig; Im, Hong G.

doi:10.1115/icef2020-2933

Cited by 4 publications

(9 citation statements)

References 18 publications

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“…Mesh for standard bowl-geometry at different start of injection timings [29] Figure 2. The in-cylinder pressure and rate of heat release (RoHR) traces of the CFD simulations validated against the experimental data for the single injector case [27] An n-heptane mechanism [30] accounted for the chemistry where the injected diesel was assumed n-heptane upon evaporation. Thus, the simulations assumed liquid diesel injection followed by gaseous n-heptane, with an adjusted lower heating value.…”

Section: Cfd Simulationsmentioning

confidence: 90%

“…removed pip to reduce heat losses with side-injection only, as shown in Figure 4. This followed from a previous study [27] where a flat piston-bowl reduced the heat losses for two-injector cases.…”

Section: Tested Conditions Injector Configuration and Chamber Geometrymentioning

confidence: 97%

“…3D computational fluid dynamics (CFD) simulations evaluated the DCEE combustor performance based on results from previous studies [27,28]. The software Converge, version 2.4, used the Reynolds-averaged Navier-Stokes (RANS) approach to find the combustor's convective heat transfer losses and its indicated efficiency.…”

Section: Cfd Simulationsmentioning

confidence: 99%

“…All CFD simulations in this study adhere to simulations performed in our previous work [26,27]. The CFD simulation conditions follow the combustion cylinder of the DCEE concept [35] with: a low compression ratio of 11.5; a high intake temperature of 464.15 K; and high intake pressure at 5 bar.…”

Section: Tested Conditions Injector Configuration and Chamber Geometrymentioning

confidence: 99%

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A Simulation Study to Understand the Efficiency Analysis of Multiple Injectors for the Double Compression Expansion Engine (DCEE) Concept

Goyal

Nyrenstedt

Cabezas

et al. 2021

SAE Technical Paper Series

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Heavy-duty vehicles face increasing demands of emission regulations. Reduced carbon-dioxide (CO2) emission targets motivate decreased fuel consumption for fossil fuel engines. Increased engine efficiency contributes to lower fuel consumption and can be achieved by lower heat transfer, friction and exhaust losses. The double compression expansion engine (DCEE) concept achieves higher efficiency, as it utilizes a split-cycle approach to increase the in-cylinder pressure and recover the normally wasted exhaust energy. However, the DCEE concept suffers heat losses from the high-pressure approach. This study utilizes up to three injectors to reduce the wall-gas temperature gradient rendering lower convective heat losses. The injector configuration consists of a standard central injector and two side-injectors placed at the rim of the bowl. An increased distance from side-injector to the wall delivered lower heat losses by centralizing hot gasses in the combustion chamber. Computational fluid dynamics (CFD) simulations investigated two different piston bowls, in a heavy-duty diesel engine, to obtain in-cylinder conditions for one, two -and three-injector concepts. One-dimensional (1D) simulations then used the CFD data to obtain the complete efficiency analysis of the DCEE concept. The results showed that the three-injector case improved the brake thermal efficiency and reduced the heat transfer losses, compared to the two-injector and single-injector cases. In particular, the three-injector case resulted in a high indicated and brake thermal efficiency of 58.5 % and 54.2 %, respectively.

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Section: Cfd Simulationsmentioning

confidence: 90%

Section: Tested Conditions Injector Configuration and Chamber Geometrymentioning

confidence: 97%

Section: Cfd Simulationsmentioning

confidence: 99%

Section: Tested Conditions Injector Configuration and Chamber Geometrymentioning

confidence: 99%

See 2 more Smart Citations

A Simulation Study to Understand the Efficiency Analysis of Multiple Injectors for the Double Compression Expansion Engine (DCEE) Concept

Goyal

Nyrenstedt

Cabezas

et al. 2021

SAE Technical Paper Series

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“…To investigate the impact of three injectors on the energy distribution, the best side injector case was performed together with the central injector. Previous studies highlighted the use of multiple injectors with swirl [42]. However, this study includes no swirl since the engine swirl ratio remains close to zero.…”

Section: Design Of Experimentsmentioning

confidence: 99%

Energy Distribution Analysis of Multiple Injectors for the Double Compression Expansion Engine Concept

Goyal¹,

Jiminez

Nyrenstedt

et al. 2021

SAE Int. J. Engines

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The present study shows the impact of multiple injectors with distinctive spray and injection angles on the engine efficiency, heat transfer, and exhaust losses. It is well known from previous studies that multiple injectors, particularly two-injectors, improve the air-fuel mixing while simultaneously reducing the heat transfer losses by keeping hot reaction zones away from the combustion cylinder walls. However, it is unclear how the spray-to-spray, umbrella, and spray-orientation angles would impact the overall energy distribution in both the combustion cylinder and double compression expansion engine (DCEE) concept. In this study, three-dimensional (3-D) Reynold-averaged Navier-Stokes (RANS) simulations were conducted in a heavy-duty single-cylinder engine, comparing three-injectors and two different side-injectors cases with a baseline case of centrally mounted single-injector. To obtain the baseline case and validate the computational fluid dynamics (CFD) data, the engine was operated at 1200 rpm, and the fuel mean effective pressure (FuelMEP) of 40 bar using conventional diesel fuel was fixed. One-dimensional (1-D) simulations then utilized the CFD-based in-cylinder pressure and rate of heat release (RoHR) traces to analyse the energy distribution of the DCEE concept. The CFD results show that the three-injectors and the best side-injectors case lead to 1.2%-points and 0.2%-points improvement of gross indicated efficiency and heat losses reduction of 1.3%-points and 2%-points, respectively, compared to the baseline single-injector case. This is due to the longer injector-wall distance from the side-injections, thereby reducing the heat transfer losses, compared to the large coverage area of the high-temperature gases for the baseline case. The 1-D results show that a high brake thermal efficiency of 53% and 52.7% can be achieved with the three-injectors and the best sideinjectors case, respectively, compared to 51.9% of the baseline case. This was due to the advanced combustion phasing, lower heat transfer losses, and higher conversion efficiency of exhaust losses from the combustion cylinder into useful work in the expansion cylinder of the DCEE concept, resulting in an overall higher engine efficiency for multiple injectors.

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Injection Strategies and Auto-Ignition Features of Gasoline and Diesel Type Fuels for Advanced CI Engine

AlRamadan

Nyrenstedt

2022

Gasoline Compression Ignition Technology

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Computational Fluid Dynamics Investigation on Multiple Injector Concepts at Different Swirl Ratios in a Heavy Duty Engine

Cited by 4 publications

References 18 publications

A Simulation Study to Understand the Efficiency Analysis of Multiple Injectors for the Double Compression Expansion Engine (DCEE) Concept

A Simulation Study to Understand the Efficiency Analysis of Multiple Injectors for the Double Compression Expansion Engine (DCEE) Concept

Energy Distribution Analysis of Multiple Injectors for the Double Compression Expansion Engine Concept

Injection Strategies and Auto-Ignition Features of Gasoline and Diesel Type Fuels for Advanced CI Engine

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