Article
Chemistry, Physical
Isabel Amez, Blanca Castells, Marcelo F. Ortega, Bernardo Llamas, Javier Garcia-Torrent
Summary: The study investigates the use of hydrogen-enriched biogas in a conventional combustion system, showing significant improvement in flame stability when hydrogen composition is between 5% and 10%.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Ahlem Ghabi, Pablo Escot Bocanegra, Brahim Sarh, Eric Robert, Toufik Boushaki
Summary: This study investigates the effects of microsecond pulsed plasma on the stabilization and emission characteristics of non-premixed swirling biogas/air flames. The results show that microsecond pulsed plasma improves flame stability and reduces CO concentration in the flue gases.
Article
Thermodynamics
Jinhoon Choe, Wenting Sun, Timothy Ombrello, Campbell Carter
Summary: This study demonstrates that plasma can reduce NOx emissions and extend the lean blowoff limits of ammonia flames, in contrast to previous research using hydrocarbon fuels. These findings could pave the way for practical application of plasma in ammonia combustion.
COMBUSTION AND FLAME
(2021)
Article
Energy & Fuels
Gyongyver Tothpalne Hidegh, Bertalan Pizag, Agnes Urbin, Erika Racz, Viktor Jozsa
Summary: Distributed combustion is an ideal choice for boilers, furnaces, and gas turbines due to its advantages of low pollutant emission, low susceptibility to instability, and high fuel flexibility. This study focuses on the Mixture Temperature-Control approach, emphasizing the need for online flame control and the evaluation of chemiluminescent emission peaks. The characteristics of distributed flames are compared to well-known straight and V-shaped flames, showing lifted combustion without a distinctive shape and a low OH*/CH* ratio.
Article
Energy & Fuels
Qifu Lin, Yiman Jiang, Chengzhou Liu, Longwei Chen, Wenjin Zhang, Jun Ding, Jiangang Li
Summary: This study combines a gliding arc plasma reactor with a swirl burner to enhance ammonia combustion performance and reduce NO emission. By adjusting the gas discharge medium, equivalence ratio, and gas flow rate, the experimental results show a significant reduction in NO emission during ammonia combustion. These findings have important applications in the ammonia fuel industry.
Article
Thermodynamics
Yao Liu, Jianguo Tan, Zhengwang Gao, Taiyu Wang, Minggang Wan
Summary: The study investigated the characteristics of chemiluminescence and NOx emissions under different conditions, finding a linear relationship between them, enabling the monitoring of NOx emissions through the chemiluminescence technique.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Energy & Fuels
Bugrahan Alabas
Summary: This study investigated the effect of adding biogas to a propane flame on combustion instability and luminous intensity. The results showed that the addition of biogas suppressed the combustion instabilities of the propane flame and increased the brightness of the flame.
Article
Chemistry, Multidisciplinary
Chengjie Bai, Shi Li, Tong Chen, Xiaoxiao Chen, Wenjing Meng, Jie Pan
Summary: Through numerical investigation, this study examined the effects of inert gas dilution on methane-air NRP discharge plasma ignition process and related reaction mechanisms, showing that the addition of inert gases significantly reduces ignition delays.
Article
Thermodynamics
Igor Yakovlev, Daniil Astakhov, Sergey Zambalov, Roman Fursenko, Jun Li, Anatoly Maznoy
Summary: This study investigates the mechanisms and characteristics of flame oscillations in porous burners using numerical simulations. The results show that unstable flame oscillations can cause velocity pulsations in adjacent pore channels, which affects the stability and combustion efficiency of the flame.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Muhammed S. Abdallah, Mohy S. Mansour, Nageh K. Allam
Summary: The study investigated the combustion characteristics of biogas under partially premixed mode and evaluated the stability of flames using a concentric flow slot burner. The results showed that LD10 is the optimum premixing ratio to generate a stable biogas flame at all tested CO2 proportions, while increasing the CO2 content led to a weak and unstable flame.
Article
Thermodynamics
Jinhoon Choe, Wenting Sun
Summary: This study examines the impact of nano-second pulsed non-equilibrium plasma on ammonia combustion in a gas turbine combustor. The results show that plasma can enhance flame stabilization and extend the attached flame regime at lower equivalence ratios. The coupling effects between plasma kinetics and flame dynamics are investigated through NH2 * chemiluminescence and OH PLIF measurements. The findings suggest that NH2 * production in plasma-assisted ammonia oxidation is possibly linked to the production of OH or oxygen-related species.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Chemical
Rolandas Paulauskas, Ernest Bykov, Kestutis Zakarauskas, Nerijus Striugas, Raminta Skvorcinskiene
Summary: Biogas has the potential to solve methane emissions, utilization of bio-waste, and replacement of fossil fuels. However, its lower calorific value and varying methane concentration can result in flame instability and increased pollution. This study investigates the effect of ozone on flame chemiluminescence and pollutant emissions from biogas flames.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Energy & Fuels
Yong Tang, Qiang Yao, Jiankun Zhuo, Shuiqing Li
Summary: The study shows that dielectric-barrier-discharge plasma can enhance the low-temperature pyrolysis and high-temperature oxidation of liquid fuels, decompose large hydrocarbons, and lower the ignition temperature of fuels. Experimental results were measured using gas chromatography and planar laser induced fluorescence techniques.
Article
Chemistry, Physical
Li Guo, Ming Zhai, Shijie Xu, Qianhao Shen, Peng Dong, Xue-Song Bai
Summary: The study demonstrates that the addition of hydrogen can widen the stable combustion range of methane/air flames in micro confined spaces, increase the frequency and maximum propagation velocity of FREI flames, and decrease the quenching distance of CH4/H2/air flames.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Dirren Govender, Hecong Liu, Fan Peng, Weiwei Cai, Nicholas A. Worth
Summary: This study investigated azimuthally forced spinning modes on a single ethylene-air swirl flame in an annular combustor using phase-averaged three-dimensional Computed Tomography of Chemiluminescence. The experiment introduced strongly spinning modes in both clockwise and anticlockwise directions through controlled acoustic forcing. The results showed that the flame shape in a single flame configuration differed from previous multi-flame investigations, with less flame-wall and no flame-flame interactions. The global heat release rate response was the same for both forcing directions in the absence of significant enclosure effects. The study also analyzed the 3D oscillation distributions of heat release rate and revealed rotational symmetry in the flame response to modes with opposite spin direction. High magnitude heat release rate oscillations were observed near the flame base, with concentrations close to the inner or outer annular walls during clockwise or anticlockwise excitation, respectively. The findings contribute to a better understanding of the global flame response to azimuthal excitation. Rating: 7/10.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Agricultural Engineering
Mindaugas Bulota, Darius Ciuzas, Edvinas Krugly, Ingrida Pauliukaityte, Odeta Baniukaitiene, Dainius Martuzevicius
Summary: A new method was developed in this study for preparing lightweight fiber-reinforced composites, which combined cellulose dissolution, fiber production through electrospinning, and composite preparation. The use of ionic liquid BMIMAc in the electrospinning process effectively prevented fiber fusion, resulting in strong, tough fiber-reinforced composites.
INDUSTRIAL CROPS AND PRODUCTS
(2022)
Article
Energy & Fuels
R. Paulauskas, R. Skvorcinskiene, K. Zakarauskas, N. Striugas
Summary: This study focuses on enhancing low-calorific gas combustion through oxygen enrichment and ozone produced by plasma. The combustion enhancement by ozone is found to be related to methane concentration and oxygen enrichment level, with a more pronounced effect at lower oxygen levels.
Article
Thermodynamics
Ravi Patel, Jeroen van Oijen, Nico Dam, Sander Nijdam
Summary: This study presents an experimental investigation on dielectric barrier discharge (DBD) plasma-assisted ignition in methane-air flows at near-atmospheric pressure. The results show that the DBD filamentary plasma is a fast, repetitive, and low-temperature ignition source that can achieve ignition-stabilized combustion under various conditions.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
J. Eimontas, N. Striugas, K. Zakarauskas, I. Kiminaite
Summary: The eutrophication processes and water pollution caused by marine plastic waste are significant ecological problems. This study analyzed the used fishing nets and found that thermal treatment at 700 degrees Celsius with Y-Type catalyst could result in a high yield (96%) of caprolactam. This research provides insights for the recovery and utilization of marine plastic waste in a circular economy.
Article
Thermodynamics
Samy Yousef, Justas Eimontas, Nerijus Striugas, Marius Praspaliauskas, Mohammed Ali Abdelnaby
Summary: This research aims to study the catalytic pyrolysis of glass fibre-reinforced epoxy resin composites mixed with different fillers over zeolite catalyst. The experimental results show that the hybrid catalyst can significantly enhance the formation of aliphatic compounds and phenol compounds, reduce the energy required for decomposition, and demonstrate good consistency with increasing heating rates and addition of hybrid catalysts.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Energy & Fuels
Justas Eimontas, Adolfas Jancauskas, Kestutis Zakarauskas, Nerijus Striugas, Lina Vorotinskiene
Summary: The uncollected seaweed and macroalgae have caused eutrophication, which is a significant and ongoing ecological issue. This paper investigates the potential use of seaweed as a feedstock in the slow-pyrolysis process through microthermal analysis combined with Fourier transform infrared spectrometry and laboratory-scale experiments with different temperatures and catalysts. The results show that seaweed decomposes in two stages at 250 and 700 degrees C, and the catalyst lowers the activation energy and decomposition temperatures. The experiments reveal that the gaseous phase contains CnHm, H-2, CO, and CO2, while the liquid fraction derivatives include substituted phenolic compounds, pyridine, benzoic acid, naphthalene, d-glucopyranose, and d-allose. The catalyst also converts higher molecular mass compounds into toluene (71%), making this technology attractive for the recovery of higher-added-value products.
Article
Energy & Fuels
Samy Yousef, Vidas Lekavicius, Nerijus Striugas
Summary: During the COVID-19 pandemic, there was a significant increase in surgical mask waste (WM) in the EU region, and managing and recycling them became a challenge. This study analyzed the techno-economic viability of pyrolysis and gasification processes for converting WMs into pyrolysis oil and hydrogen-rich syngas. The results showed that gasification had higher economic performance compared to other methods, such as incineration and pyrolysis.
Article
Engineering, Chemical
Edvinas Krugly, Preethi Ravikumar, Lauryna Dabasinskaite, Martynas Tichonovas, Darius Ciuzas, Tadas Prasauskas, Odeta Baniukaitiene, Goda Masione, Violeta Kauneliene, Dainius Martuzevicius
Summary: This manuscript presents the application of nanofibrous filtration technology for aerosol sampling through the fabrication and validation of sampling filters. Four composite filters were created using different polymers, and their layered structure allowed for efficient particle collection and low pressure drop. The obtained results indicate that these filters are suitable for customized filtering substrates for subsequent analysis of collected particles.
JOURNAL OF AEROSOL SCIENCE
(2023)
Article
Physics, Fluids & Plasmas
Siebe Dijcks, Martijn van der Leegte, Sander Nijdam
Summary: A methodology is proposed to investigate the structure of streamer discharge trees using advanced imaging techniques. Stereoscopic and stroboscopic techniques are employed to capture the depth and temporal information of the stochastic and transient streamers. A semi-automated post-processing algorithm is developed to reconstruct the streamer discharge tree and characterize its morphology using velocity, diameter, and trajectory.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Ravi Patel, Jeroen van Oijen, Sander Nijdam, Nico Dam
Summary: This study investigates the effects of pulse repetition rate (PRR) and flow speed on dielectric barrier discharge (DBD) plasma pulse-to-pulse coupling and ignition of methane-air flows. Experiments are conducted using a homemade DBD flow reactor with a 5 mm discharge gap. High-speed intensified imaging shows that plasma morphology transitions from multiple weak filaments to a few stronger filaments, indicating pulse-to-pulse coupling. The study emphasizes the importance of pulse-to-pulse coupling for successful ignition in methane-air flows, identifying critical PRR and minimum number of pulses required for coupling.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Energy & Fuels
Ieva Kiminaite, Judith Gonzalez-Arias, Nerijus Striugas, Justas Eimontas, Martin Seemann
Summary: The COVID-19 pandemic has led to increased plastic pollution due to the extensive use of PPE worldwide. To address this issue, proper management of PPE disposal is necessary. The steam gasification/pyrolysis technique offers a reliable solution for chemically recycling these wastes into valuable products. Experimental results show that the process temperature significantly affects the composition of gases produced, with higher temperatures promoting the synthesis of syngas. This study demonstrates that the thermo-chemical conversion process is a feasible route for converting used face masks into valuable products such as syngas.
Article
Thermodynamics
R. Skvorcnskiene, I. Kiminaite, L. Vorotinskiene, A. Jancauskas, R. Paulauskas
Summary: Today's society faces the dual challenge of resource depletion and waste accumulation. There is a growing demand to replace conventional plastics with bioplastics in the market, but the sustainability of bioplastics compared to conventional plastics remains a subject of debate due to limited research. This study investigates the degradation characteristics of bioplastics in soil (ATR-FTIR), their thermal stability under pyrolysis, and their suitability for waste-to-energy conversion using thermal analysis (TG) and evolved gas analysis (FTIR). The biodegradation experiments reveal that only corn starch-based bioplastics can completely and rapidly degrade in soil, while other bio-based and petroleum-based plastics only undergo color change and softening. This indicates that bioplastics undergo thermochemical alteration and closely resemble conventional plastics, necessitating proper recycling or conversion into energy to avoid becoming a source of microplastics. Thermogravimetric analysis coupled with evolved gas analysis (TGA-FTIR) shows that the gas yield from bioplastics ranges from 80-99%, with degradation onset occurring at temperatures ranging from 203.0-272.5 degrees C in a nitrogen environment, or 10-20 degrees C lower in a steam-enriched environment. The main volatile products of bioplastics pyrolysis are carboxylic compounds, alkanes, alkenes, aromatic hydrocarbons, amines, CO, and CO2, depending significantly on the chemical composition of the plastic.
Article
Physics, Fluids & Plasmas
Zhen Wang, Siebe Dijcks, Yihao Guo, Martijn van der Leegte, Anbang Sun, Ute Ebert, Sander Nijdam, Jannis Teunissen
Summary: Streamer discharges are the main mode of electric breakdown in air, and the branching behavior of streamer channels plays a crucial role in determining the discharge structure. In this study, we used a 3D fluid model with photoionization to simulate the branching of positive streamers in air. Our results show that the probability and morphology of branching are in good agreement with experimental data, supporting the validity of Zheleznyak's photoionization model.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Thermodynamics
Cong Li, Jiali Wang, Chenhui Wang, Yanke Jin, Yina Yao, Rui Yang
Summary: This study investigates the impact of NaCl water droplets with various concentrations on a heated surface. The results show that the impact patterns can be categorized into different types, and models are established to predict the spreading behavior of droplets with different concentrations. Additionally, high concentration droplets exhibit more violent boiling and have lower residual energy and rebound time.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
C. Barrera, V. Castro, F. Escudero, J. J. Cruz, I. Verdugo, J. Yon, A. Fuentes
Summary: This study focuses on the characterization of soot maturity and sooting propensity of anisole fuel in a controlled laminar coflow diffusion flame. The results show that the spatial distribution of soot volume fraction is enhanced near the flame centerline, while soot production is promoted near the flame wings. The temperature increase also affects the maturity of soot particles.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Roman W. Morse, Jason Chan, Tiago A. Moreira, Jared J. Valois, Evan T. Hurlburt, Jean-Marie Le Corre, Arganthael Berson, Kristofer M. Dressler, Gregory F. Nellis
Summary: This study investigates the dryout of liquid film and the role of disturbance wave frequency. Experimental results indicate that the heat transfer coefficient associated with optimal boiling conditions is maximized when the surface is dry 5% of the time, independent of pulse amplitude and frequency. Liquid-film measurements, dryout statistics, and direct observation suggest that disturbance-wave frequency can be manipulated by density-wave oscillations in the flow field.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
E. J. Vega, J. M. Montanero
Summary: In this study, we experimentally investigated the bursting of a bubble covered with a surfactant. We found that the bubble bursting time is longer compared to a surfactant-free bubble due to interfacial elasticity. Furthermore, the Marangoni stress drives liquid flow that allows the jet to escape from the end-pinching mechanism within a certain surfactant concentration range.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Guofu Sun, Yi Zhan, Tomio Okawa, Mitsuhiro Aoyagi, Akihiro Uchibori, Yasushi Okano
Summary: Experiments were conducted on liquid jets ejected from oval nozzles to investigate the effects of nozzle orifice shape on jet behavior. The study found that the liquid jet exhibited different characteristics at different liquid flow rates. Correlations were established to predict the liquid jet state and characteristics of the secondary droplets produced during jet impact onto a solid surface. This research extended the available knowledge on liquid jet behavior.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Jeonghoon Lee, Laurent Zimmer, Takeshi Saito, Shinji Nakaya, Mitsuhiro Tsue
Summary: This study investigates the effects of spatial resolution on DMD amplitudes and spatial mode strengths, and proposes scaling factors to correct for the resolution differences. The results show that the proposed scaling factors successfully normalize the amplitudes and spatial modes, allowing for quantitative comparison of data obtained with different spatial resolutions. This study is significant for analyzing spatiotemporal data in various fields.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Yanli Zhao, Shibing Kuang, Xiaoliang Zhang, Mingjun Xu
Summary: This study experimentally investigates the dynamic process of water droplet impacting different wood surfaces and analyzes and discusses the impacting phenomena, phenomena distribution, droplet spreading dynamics, and maximum spread factor. The results show that the impacting process can be distinguished by Weber numbers and Reynolds numbers, and can be predicted by mathematical expressions.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Aakhash Sundaresan, Atul Srivastava, Callum Atkinson
Summary: This study presents the first-ever application of an advanced methodology, combining two-color laser-induced phosphorescence and particle image velocimetry, to investigate the heat transfer mechanisms on the surface of a cylinder placed inside a confined square duct. The technique allows for simultaneous measurement of velocity and temperature fields, reducing the complexity and costs associated with separately measuring temperature distributions. Experimental observations show that increasing the mass flow rate enhances heat removal from the cylinder surface, and increasing the cylinder heat input enhances heat transfer in the rear portion of the cylinder.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Harish K. Patel, Sukhjeet Arora, Rutuja Chavan, Bimlesh Kumar
Summary: This study experimentally analyzed the multiscale statistical assessment of scour depth surrounding spur dikes with downward seepage. The research found that seepage affects the morphological behavior and hydrodynamic characteristics of the channel bed, leading to changes in scour formation. The rate of scour depth changes initially increases with higher seepage velocity but eventually becomes constant over time.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Justas Sereika, Paulius Vilkinis, Gediminas Skarbalius, Algis Dziugys, Nerijus Pedisius
Summary: This study experimentally investigated the pulsatile flow structure based on a transitional-type cavity. It was found that the pulsation amplitude has a more significant effect on the dynamics of recirculation zone than the pulsation frequency. Pulsatile flow can reduce the size of the recirculation zone.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Merav Arogeti, Eran Sher, Tali Bar-Kohany
Summary: This study provides a detailed exploration of the events that occur when a droplet hits a dry solid surface of various small sizes, with a focus on the deposition, receding breakup, and prompt splash phases. By utilizing non-dimensional analysis and graphical representation, the boundaries between different events are defined, and criteria for differentiation based on target-to-drop ratio, Reynolds, and Webber numbers are presented.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Tianxiong Li, Fei Wen, Yingchun Wu, Botong Wen, Lei Wang, Jinxin Guo, Xuecheng Wu
Summary: This study investigates the structure of the flow field induced by a strut in a scramjet and its influence on flame stabilization. Experimental and numerical analyses reveal that the flow field exhibits features beneficial for flame stabilization, but the asymmetry of the flow poses a challenge to flame establishment.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Syed Ehtisham Gillani, Yasir M. Al-Abdeli
Summary: This study investigates the asymmetry in bluff-body stabilised annular jets and finds that swirl can significantly mitigate the asymmetry and restore the symmetry of the jets. Moreover, increasing the Reynolds number and the swirl intensity can both decrease the asymmetry of the jets.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Utsav Bhardwaj, Rabindra Kumar, Shyama Prasad Das
Summary: This study presents an experimental investigation on flooding phenomenon in a pulsating heat pipe (PHP) unit cell, and analyzes the impact of flooding on the performance of PHP. The study recognizes three different flooding mechanisms and finds that currently accepted correlations for predicting flooding velocity are inaccurate. The study emphasizes the need for further research on flooding in PHPs.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Yunpeng Xue, Yongling Zhao, Shuo-Jun Mei, Yuan Chao, Jan Carmeliet
Summary: This study investigates the impact of building morphology on local climate, air quality, and urban microclimate. The researchers conducted an experimental investigation in a large-scale water tunnel, analyzing heat and flow fields using Laser-induced Fluorescence (LIF) and Particle Image Velocimetry (PIV). The findings show that factors such as canyon configuration, buoyant force, and approaching flow magnitude significantly influence fluid flow in street canyons, and the morphology of the street canyon dominates ventilation rate and heat flux. For example, changing the aspect ratio of a street canyon can lead to a significant change in air ventilation rate, ranging from 0.02 to 1.5 under the same flow conditions.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)