Article
Mechanics
A. Pandal, B. M. Ningegowda, F. N. Z. Rahantamialisoa, J. Zembi, H. G. Im, M. Battistoni
Summary: Modeling spray in a dense near-nozzle region remains a significant challenge, but the new Sigma-Y spray atomization model, incorporating liquid diffusion and interfacial dynamics, accurately predicts behavior under all relevant engine conditions and overcomes limitations of previous formulations.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Mechanics
Jordi Poblador-Ibanez, Lorenzo Nocivelli, Gina M. Magnotti, Lakshman Anumolu, Brandon A. Sforzo
Summary: The atomization of a liquid jet is a complex problem with multiple scales and physics, which affects the efficiency of combustion engines. In this study, a modified E-Y model is used to transport the surface area density of the spray, and its predictive performance is evaluated under various operating conditions. The results show that the model has good predictive capabilities.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Energy & Fuels
Jesus Benajes, Jose M. Garcia-Oliver, Jose M. Pastor, Daiana De Leon-Ceriani
Summary: Poly-Oxymethylene Dimethyl Ethers (OMEx) are synthetic and potentially-renewable fuels that can significantly reduce lifecycle CO2 emissions and soot emissions. Computational studies show that both OMEx and OME1 fuels have similar ignition timings to the reference fuel n-dodecane, and ignition in spray calculations occurs on the lean side. The modeling approach predicts most combustion metrics and temperatures for both fuels.
Review
Green & Sustainable Science & Technology
Djati Wibowo Djamari, Muhammad Idris, Permana Andi Paristiawan, Muhammad Mujtaba Abbas, Olusegun David Samuel, Manzoore Elahi M. Soudagar, Safarudin Gazali Herawan, Davannendran Chandran, Abdulfatah Abdu Yusuf, Hitesh Panchal, Ibham Veza
Summary: Research and development in the internal combustion engine have been growing, and diesel engines have advantages in efficiency, power output, and reliability. Although observing diesel spray is complex due to its high-speed, high-pressure, and high-temperature conditions, some mechanisms have been explained and suggestions have been made. This paper comprehensively reviews the current status of theoretical diesel spray and modeling.
Article
Thermodynamics
Vladimir Markov, Bowen Sa, Sergey Devyanin, Leonid Grekhov, Vsevolod Neverov, Jianhui Zhao
Summary: Vegetable oil-based biofuels, such as DF and RO, show promise as carbon-neutral alternatives to fossil fuels. This study focuses on comparing the injection and spray characteristics of DF and RO, as well as their relationship with emission formation. The results suggest that RO has lower injection velocity and TKE compared to DF. Increasing the RO content leads to changes in spray angle, spray tip penetration, SMD, and the mass fraction of fuel injected onto the combustion chamber walls. Additionally, a correlation is found between NOx emissions and SMD.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
F. J. Salvador, J. M. Pastor, J. Gomez-Soriano, E. C. Martinez-Miracle
Summary: This paper presents a computational study on the differences between a convergent and a constant section elliptical nozzle. Coupled internal-external flow simulations were performed using a sigma-Y model that was experimentally validated. The results show that cavitation is an important factor in the elliptical nozzle geometries, affecting the internal flow and spray parameters. The study suggests a potential for improving the mixture using cavitating elliptical nozzles.
Article
Energy & Fuels
Zhixia He, Bihe Hu, Jianquan Wang, Genmiao Guo, Zehao Feng, Chuqiao Wang, Lian Duan
Summary: This paper investigates the effects of gasoline-diesel mixing ratio on the cavitation flow and spray characteristics of blended fuels. It is found that the addition of gasoline enhances the string cavitation strength and injection rate, but has little influence on the maximum intensity and duration of string cavitation. Moreover, gasoline addition increases the overall spray cone angle and fluctuations. These findings provide important guidelines for fuel injection strategies and spray analysis of gasoline-diesel blends in compression-ignition engines.
Article
Energy & Fuels
Zhaowen Wang, Xiaojie Li, Lin Xiang, Yuhan Huang, Bing Lang, Xiaobei Cheng, Jie Zhang
Summary: This study compares the spray combustion characteristics of neat diesel, neat RP-3 and RP-3/diesel blends under different conditions. The results show that the blending ratio of RP-3 has significant effects on the spray and combustion processes. RP-3/diesel blends exhibit faster evaporation and lower soot emissions than neat diesel and RP-3 alone.
Article
Thermodynamics
Haoyu Ding, Jin Zhao, Zhenyu Zhang, Kai Xu, Luxin Fu, Xu He
Summary: The factors influencing the formation of impinged spray are analyzed using computational fluid dynamics (CFD) modeling. Free spray and impinging sprays with three impinging distances are simulated using the Eulerian-Lagrangian multiphase method. The results are validated with experimental data. The impact of air flow, generated by gas entrainment of spray, also influences the spray.
Article
Energy & Fuels
Suya Gao, Junhao Yan, Timothy H. Lee, Chia-Fon Lee
Summary: The objective of this study is to develop a comprehensive model for spray atomization considering flash boiling, and to validate the model through simulations and experiments. The results show that the flash boiling model accurately captures the spray characteristics under different conditions, indicating the effectiveness of the model.
Article
Agronomy
Illia Chyrva, Mark Jermy, Tara Strand, Brian Richardson
Summary: This study successfully developed a model for multicopter wake and particle dispersion, which is computationally economical and reasonably accurate. The model was validated against field tests and showed sensitivity to various flight parameters. It provided reasonable predictions for different flight trials.
PEST MANAGEMENT SCIENCE
(2023)
Article
Energy & Fuels
Zhijie Zhu, Xingyu Liang, Lei Cui, Kun Wang, Xiaohui Wang, Shihao Zhu
Summary: Currently, most ships still rely on fossil fuels as the main source for marine engines. However, diesel as a fuel for marine engines is no longer sufficient to meet the economic requirements of shipping and emission restrictions imposed by regulations. This research examined the viability of employing hydrogen-carrying fuel ammonia (NH3) in marine engines to develop a low-carbon combustion technology, to address the carbon emission problem of marine diesel engines.
Article
Energy & Fuels
Camille Hespel, Chetankumar Patel, Tung Lam Nguyen, Ob Nilaphai, Christine Mounaim-Rousselle
Summary: This study explores the potential use of ABE mixture as an alternative fuel for CI engines. The experiment showed that increasing the ABE and Butanol concentration in the blends led to a longer ignition delay and lift-off length, as well as a decrease in soot concentration. The blends with the lowest ABE or Butanol content exhibited similar combustion characteristics to n-dodecane, making them suitable substitutes for diesel without any engine modifications.
Article
Energy & Fuels
Bowen Sa, Vladimir Markov, Ying Liu, Vyacheslav Kamaltdinov, Wenpei Qiao
Summary: By analyzing the thermal-physical properties of multi-walled carbon nanotubes (MCNTs) and MCNT blended diesel fuel, it was found that adding MCNTs increased turbulence and affected spray development process, while having insignificant influence on vapor penetration length.
Article
Nuclear Science & Technology
Seokwon Whang, Hyun Sun Park, Jongtae Kim
Summary: This study aims to conduct a detailed analysis on the role of the spray system in severe accidents in nuclear power plants, focusing on the effects of the buoyancy term and droplet size in turbulence models on mixing characteristics.
NUCLEAR ENGINEERING AND DESIGN
(2021)
Article
Thermodynamics
Jacopo Zembi, Michele Battistoni, Suresh Kumar Nambully, Adrian Pandal, Cedric Mehl, Olivier Colin
Summary: Multi-cycle Large-Eddy Simulations (LES) were conducted to investigate combustion cycle-to-cycle variability (CCV) in a gasoline spark ignited engine, using the Thickened Flame Model (TFM) and adaptive mesh refinement (AMR) to achieve good resolution of the flame at acceptable costs. The study showed that combustion variability is highly correlated to resolved velocity field and turbulence intensity, affecting early flame kernel growth.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2022)
Article
Thermodynamics
Bernardo Tormos, Jose M. Garcia-Oliver, Marcos Carreres, Carlos Moreno-Montagud, Beatriz Dominguez, Maria Dolores Cardenas, Fermin Oliva
Summary: Low-speed pre-ignition (LSPI) in Direct Injection Spark Ignition (SI) engines remains a challenge due to its potential to induce heavy knock. This study aims to determine the ignition propensity of lubricant oils using optical techniques, finding that base oil formulation impacts ignition delay while additives, aging, and oxidation have minimal effect.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2022)
Article
Thermodynamics
J. Benajes, J. M. Garcia-Oliver, J. M. Pastor, I Olmeda, A. Both, D. Mira
Summary: This study focuses on flame stabilization and local extinction of a spray flame using large-eddy simulations with a tabulated chemistry method. The numerical results accurately predict relevant parameters of the flame and reveal the phenomenon of localized extinction at the leading edge of the flame.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
J. M. Garcia-Oliver, Y. Niki, R. Rajasegar, R. Novella, J. Gomez-Soriano, P. J. Martinez-Hernandiz, Z. Li, M. P. B. Musculus
Summary: The study presents experimental results on the evolution of gas jets ejected through the orifices of a pre-chamber in a heavy-duty optical engine using high-speed visible intensified imaging and low-speed infrared imaging. A one-dimensional gas jet model is employed to characterize the spatial distribution of the ejected flow, and sensitivity to variations in air-to-fuel ratio and combustion initiation timing in the pre-chamber is discussed. The one-dimensional model also indicates that the local flow exhibits highest sensitivity to operating conditions during the start of ejection until the timing when maximum flow is attained.
Article
Thermodynamics
Jose Pastor, Jose M. Garcia-Oliver, Carlos Mico, Alba A. Garcia-Carrero
Summary: This research compares two injectors for different fuels in terms of spray characteristics and combustion behavior, showing that the Spray D injector has longer liquid length, faster vapor penetration, higher ignition delay, and longer lift-off length. The oxygenated fuel OME exhibits a different trend in ignition behavior compared to other fuels, and no soot production was observed with oxygenated fuels under any operating conditions.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2022)
Article
Engineering, Chemical
Alain Islas, Andres Rodriguez-Fernandez, Covadonga Betegon, Emilio Martinez-Paneda, Adrian Pandal
Summary: Dust explosions pose a significant risk to industrial facilities, and it is crucial to understand the severity parameters of dust clouds for safety management and risk assessment. This study successfully validated a computational model that simulates the dispersion process of dust clouds, and it also explored the impact of particle size on turbulence and particle distribution.
Article
Engineering, Environmental
Alain Islas, Andres Rodriguez Fernandez, Covadonga Betegon, Emilio Martinez-Paneda, Adrian Pandal
Summary: This study conducted numerical simulations of biomass dust explosions using the open-source CFD code OpenFOAM and found that the characteristics of cold flow, particle size, dust concentration, and ignition delay time have significant effects on the explosion process.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Energy & Fuels
Luis Santamaria, Monica Galdo Vega, Adrian Pandal, Jose Gonzalez Perez, Sandra Velarde-Suarez, Jesus Manuel Fernandez Oro
Summary: This study validates a custom-built apparatus for airfoil testing and analyzes the physical reasons for discrepancies in the data. Experimental tests on the DU06-W-200 airfoil in a wind tunnel show remarkable agreement with other data sources. The study also provides interesting insights into the unsteady fluid dynamics of the turbine using both experimental and CFD techniques. The findings have significant implications for the application of vertical axis wind turbines.
Article
Energy & Fuels
Jesus Benajes, Jose M. Garcia-Oliver, Jose M. Pastor, Daiana De Leon-Ceriani
Summary: Poly-Oxymethylene Dimethyl Ethers (OMEx) are synthetic and potentially-renewable fuels that can significantly reduce lifecycle CO2 emissions and soot emissions. Computational studies show that both OMEx and OME1 fuels have similar ignition timings to the reference fuel n-dodecane, and ignition in spray calculations occurs on the lean side. The modeling approach predicts most combustion metrics and temperatures for both fuels.
Article
Mechanics
David P. Schmidt, Marco Arienti, Jose M. Garcia-Oliver, Jose M. Pastor
Summary: This paper explores the similarity between momentum and liquid volume fraction in non-evaporating, mixing-limited sprays using mathematical analysis and simulation experiments. It also highlights some subtle differences in the definition of spray velocity and confirms the finite mixing nature of the simulations.
Article
Green & Sustainable Science & Technology
Ahmed Gharib Yosry, Eduardo Alvarez Alvarez, Rodolfo Espina Valdes, Adrian Pandal, Eduardo Blanco Marigorta
Summary: Vertical-axis hydrokinetic turbines are a promising technology for harnessing low velocity currents. However, the interactions between the turbine rotor and the channel section, including the free-surface, have not been thoroughly investigated. In this study, a vertical-axis turbine model was designed and tested in an open channel, and a three-dimensional multiphase simulation was carried out to investigate the effects of free-surface variations on turbine performance. The experimental and numerical results showed good agreement, and the simulation model successfully captured the free-surface variations and the turbine's blockage of the channel. Additionally, the analysis of the blade-plate interaction generated vortex street.
Article
Energy & Fuels
F. J. Salvador, J. M. Pastor, J. Gomez-Soriano, E. C. Martinez-Miracle
Summary: This paper presents a computational study on the differences between a convergent and a constant section elliptical nozzle. Coupled internal-external flow simulations were performed using a sigma-Y model that was experimentally validated. The results show that cavitation is an important factor in the elliptical nozzle geometries, affecting the internal flow and spray parameters. The study suggests a potential for improving the mixture using cavitating elliptical nozzles.
Article
Energy & Fuels
R. Novella, J. Pastor, J. Gomez-Soriano, J. Sanchez-Bayona
Summary: The importance of new alternative fuels has become increasingly relevant in recent decades to mitigate global warming and pollutant emissions. Ammonia emerges as a potential fuel candidate and energy vector for internal combustion engines due to its high hydrogen content and energy density, well-developed infrastructure, and easy handling and storage. This study developed a virtual engine model to simulate different operating conditions using ammonia and hydrogen-enriched ammonia as fuel, and investigated the governing parameters of ammonia combustion using computational fluid dynamics simulations. The results showed similar thermal efficiency to methane fuel, with improvements after hydrogen enrichment, as well as the significance of intake temperature and turbulence intensity on combustion duration. Additionally, higher compression ratios were found to enhance efficiency without abnormal combustion, highlighting the need for optimizing the design paradigm of spark-ignition engines for ammonia applications.
Article
Engineering, Environmental
Alain Islas, Andres Rodriguez Fernandez, Covadonga Betegon, Emilio Martinez-Paneda, Adrian Panda
Summary: This study presents CFD simulations of biomass dust explosions using a newly developed experimental apparatus, and validates the CFD model's capability to capture transient effects. The results show excellent agreement between the model and experiments, highlighting the critical role of particle size in flame dynamics and the explosion itself. This model has great potential for future investigations of biomass dust explosions in larger-scale geometries.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Mechanics
R. Novella, J. M. Pastor, J. Gomez-Soriano, I. Barbery
Summary: This research utilizes numerical simulation to study the combustion process of spark-ignition engines with two different pre-chamber designs (tangential holes and radial holes). The results show that the tangential hole design exhibits better combustion stability and more uniform flame distribution, while the radial hole design exhibits unstable behavior and asymmetric flame evolution.
