Article
Thermodynamics
L. Angelilli, P. P. Ciottoli, T. F. Guiberti, R. Malpica Galassi, F. E. Hernandez Perez, W. R. Boyette, G. Magnotti, W. L. Roberts, M. Valorani, H. G. Im
Summary: A new method for converting OH fluorescence intensity images into OH mole fraction is proposed in this study, which does not require information on major species or temperature. The accuracy of the conversion model is estimated to about 8% and has been tested for different fuels.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Physical
Haoran Zhao, Jinhua Wang, Xiao Cai, Hongchao Dai, Zhijian Bian, Zuohua Huang
Summary: A systematic experimental study was conducted on lean premixed syngas/air turbulent expanding flames with varying turbulence intensities, initial pressures, and hydrogen volumetric fractions. Results showed that increasing turbulence intensity and initial pressure resulted in refined and wrinkled flames, leading to larger flame areas and higher turbulent burning velocities. The rise in hydrogen fraction also significantly enhanced the burning velocity due to the promotion of laminar burning velocity and diffusional-thermal instability. The study also found a unified scaling of turbulent burning velocity, indicating a practical method to correlate turbulent Reynolds number with Lewis number close to unity. Additionally, expanding flames exhibited a self-similar propagation law with a quantitative dependence of turbulent burning velocity with flame expansion.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Guo-Peng Zhang, Guo-Xiu Li, Hong-Meng Li, Jia-Cheng Lv
Summary: The study examines the effects of different diluents on the propagation characteristics of H2/CO/air mixture turbulent premixed flames. Increasing hydrogen fraction, turbulence intensity, or equivalence ratio leads to higher ST and ut. CO2 dilution shows a stronger inhibitory effect on ST compared to N2 dilution.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Xiao Cai, Qingshuang Fan, Xue-Song Bai, Jinhua Wang, Meng Zhang, Zuohua Huang, Marcus Alden, Zhongshan Li
Summary: The role of differential diffusion in highly turbulent premixed flames was investigated using NH-PLIF diagnostics. The study found that subunity Lewis number flames have a higher global consumption speed than super-unity Lewis number flames at high Karlovitz number, indicating the significant role of differential diffusion in highly turbulent flames. Although the flame surface density and area ratio are similar for flames with different Lewis numbers, the stretch factor of sub-unity Lewis number flames is significantly larger than that of super-unity cases. The enhanced global consumption speed of sub-unity Lewis number flames is suggested to be attributed to the promotion of local burning rates by the combined effect of differential diffusion and turbulent flame stretch.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Optics
Paul S. Hsu, Naibo Jiang, Daniel Lauriola, Stephen W. Grib, Stephen A. Schumaker, Andrew W. Caswell, Sukesh Roy
Summary: A 10 kHz two-color OH planar laser-induced fluorescence (PLIF) thermometry technique was demonstrated in both laminar Hencken flames and turbulent premixed jet flames, using two injection-seeded optical parametric oscillators (OPOs) pumped by a high-speed three-legged burst-mode laser. The results show promise for the use of this technique in more complex flow environments and potentially even higher repetition rates, with analyses of flame curvature, temperature, and the correlation in time of these quantities.
Article
Chemistry, Multidisciplinary
Yizhou Huang, Hui Du, Wenyu Wang, Dongkai Shi, Yimeng Wu, Bowen Li, Lei Zhou
Summary: The study found that OH radicals in the n-heptane flame are mainly concentrated in the two wings of the flame, showing a radially approximate symmetrical distribution. Both nitrogen and carbon dioxide dilutions decrease the intensity of OH radical fluorescence and the total fluorescence. The flame temperature decreases more significantly with the CO2 dilution ratio due to the combination of dilution and thermal effects.
Article
Optics
Hao Guo, Wei Zhang, Xiangyu Nie, Xue Dong, Zhiwei Sun, Bo Zhou, Zhenkan Wang, Mattias Richter
Summary: In this paper, a computational imaging method based on deep learning models is proposed to increase the temporal resolution of planar optical measurement in turbulent flames. The method utilizes down-sampled experimental data and trains networks to predict consecutive images of key combustion species. The results show that the convolutional long short-term memory network (CONV-LSTM) provides the best predictions and can generate consecutive images at higher repetition rates.
APPLIED PHYSICS B-LASERS AND OPTICS
(2022)
Article
Energy & Fuels
Lei Wang, Yong Jiang, Rong Qiu
Summary: The study reveals that the inhibitory effect of trimethyl phosphate (TMP) in turbulent premixed flames is relatively lower and may change the combustion regime from thin reaction zone (TRZ) to distributed reaction zone (DRZ). The turbulent consumption speed can be decreased significantly by the addition of TMP, and the relative inhibition efficiency in turbulent flames is much lower than in laminar configurations.
Article
Thermodynamics
Zhen Lu, Yue Yang
Summary: This study investigates the pressure effects on turbulent burning velocity and flame surface area, particularly the impact of enhanced stretch factor at high pressures. By combining sub models for stretch factor and flame surface area, a predictive model for turbulent burning velocity is developed, showing good agreement with DNS results.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Dingrui Zhang, Jian Liu, Lingyun Hou
Summary: A comprehensive understanding of the flame propagation characteristics of thermally cracked fuels is crucial for developing advanced scramjets using regenerative cooling techniques. This study systematically measured the laminar and turbulent burning velocities of thermally cracked hydrocarbon fuels and found that fuel composition has no significant influence on the laminar burning velocities. The promotional effects of pyrolysis gas on flame propagation depend on the gas-production rate and equivalence ratio. A unified scaling law for the turbulent burning velocities of thermally cracked fuels is proposed, considering the impacts of preferential diffusion.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Arun Ravi Varma, Umair Ahmed, Markus Klein, Nilanjan Chakraborty
Summary: The relationship between turbulent burning velocity, bending effect, and flame surface area is discussed, along with the effects of tangential strain rate, normal strain rate, displacement speed, and curvature.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Qingshuang Fan, Xin Liu, Leilei Xu, Arman Ahamed Subash, Christian Brackmann, Marcus Alden, Xue-Song Bai, Zhongshan Li
Summary: This paper presents experimental studies on the structures and burning velocities of premixed ammonia/air jet flames at high Karlovitz number conditions. NH and OH radicals were measured using PLIF imaging and LDA measurements. The results show that the NH layer remains thin and continuous, the NH and OH layers overlap in a thin region, and the turbulent burning velocity is linearly related to the turbulent intensity.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
S. Mohammadnejad, L. Saca, R. Heydarlaki, Q. An, P. Vena, S. Yun, P. Versailles, G. Bourque, S. Kheirkhah
Summary: Experimental investigation of multiplication of hydroxyl and formaldehyde planar laser-induced fluorescence signals for turbulent hydrogen-enriched methane-air flames with compositionally inhomogeneous mixtures reveals that stratification can lead to flame fragmentation and formation of islands with noticeable amplification of fluorescence signals. Such flame structure, due to its high occurrence rate, can result in relatively large integral of the PLIF signals multiplication.
FLOW TURBULENCE AND COMBUSTION
(2022)
Article
Energy & Fuels
Haoran Zhao, Jinhua Wang, Xiao Cai, Hongchao Dai, Zuohua Huang
Summary: Turbulent expanding flames of butanol isomers/air mixtures were studied under various conditions to determine turbulent burning velocity. The results show an increase in burning velocity with velocity and pressure. Different models provide reasonable correlations, with some scatter in the Damkohler number correlation.
Article
Energy & Fuels
Di Hou, Zunhua Zhang, Qian Cheng, Biao Liu, Mengni Zhou, Gesheng Li
Summary: The present study expands the database of laminar burning velocities for ammonia combustion and investigates the effect of N-2 addition on N-2 and NOx production. The results show that N-2 dilution decreases the laminar burning velocities and NOx concentration in NH3/O-2/N-2 flames, and the chemical effects dominate the inhibition of N-2 production at N-2 dilution rates below 0.3.
Article
Chemistry, Physical
Van Ga Bui, Thi Minh Tu Bui, Van Nam Tran, Zuohua Huang, Anh Tuan Hoang, Wieslaw Tarelko, Van Hung Bui, Xuan Mai Pham, Phuoc Quy Phong Nguyen
Summary: This paper presents the research results on the optimal fuel compositions and control parameters of a spark ignition engine fueled with syngas-biogas-hydrogen. The optimal content of hydrogen and biogas in the mixture is found to be 20% and 30% respectively. The advanced ignition angle differs between the hydrogen-syngas blend and the syngas-biogas blend, with the former having a lower angle. The engine's power decreases when switching from hydrogen or biogas fueling mode to syngas fueling mode, and there is a significant increase in NOx emissions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Wenjun Lin, Wang Han, Jinhua Wang, Runze Mao, Weijie Zhang, Xiao Cai, Zuohua Huang
Summary: The role of low-temperature chemistry/ignition (LTC/LTI) was studied in aero engine-like combustors with confined bluff-body and swirling flows. Experimental investigations were conducted on CH4/DME/air mixtures with varying DME volume fraction (αDME) to consider LTI. It was found that adding DME to lean CH4/air mixtures can introduce low-temperature flames (LTF) in the outer recirculation zone (ORZ) under certain conditions. The flame regimes were classified based on DME enrichment, and the possibility of using LTI to extend the stability margin of lean swirling flames was demonstrated.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Chemistry, Multidisciplinary
Guohua Li, Zhenrong Zhang, Jingfeng Ye, Sheng Wang, Jun Shao, Haolong Wu, Yamin Wang, Zhiyun Hu, Jinhua Wang, Zuohua Huang
Summary: In order to address the uncertainty in the calibration process of two-color plane laser-induced fluorescence (PLIF) temperature measurement, a new calibration method is proposed, taking into account the influence of fluorescence yield. The calibration process is carried out at high and low temperature regions to restrain the bias originating from quenching. This new calibration method is validated in a jet flame with a temperature range of 1300-1800 K, and the results demonstrate its effectiveness in the combustion field, especially with a large temperature range and strong quenching coefficient.
APPLIED SCIENCES-BASEL
(2023)
Article
Energy & Fuels
Lihan Fei, Mengxiao Qin, Zuohua Huang, Chenglong Tang
Summary: The hypergolic ignition behaviors of three ionic liquids [BMIm]-[DCA], [EMIm][DCA], and [EMIm][CDB] reacting with white fuming nitric acid (WFNA) were investigated. Two distinct hypergolic ignition modes were observed, with vapor smoke and sudden ejection of liquids induced by microexplosion for [BMIm][DCA] and [EMIm][DCA] and monotonic increase in temperature before ignition for [EMIm][CDB]. The time scales of vapor delay, explosion delay, and ignition delay decreased with the increase of droplet impact velocity.
Article
Energy & Fuels
Geyuan Yin, Bo Xiao, Hao Zhao, Haochen Zhan, Erjiang Hu, Zuohua Huang
Summary: An experiment was conducted to investigate the chemical kinetic effect of dimethyl ether (DME) on ammonia combustion and NO formation in a jet-stirred reactor. The mole fractions of reactants and intermediates were measured under various conditions. The key reactions were identified through pathway and sensitivity analysis. The results showed that NH2 and HO2 played important roles in ammonia oxidation, while reactions like CH3 + NO2 = CH3O + NO and HNO + O2 = NO + HO2 were essential for NO formation.
Article
Energy & Fuels
Fabio A. S. Mota, Lihan Fei, Chenglong Tang, Zuohua Huang, Fernando S. Costa
Summary: This work presents a novel green fuel system based on TMEDA, DMEA, and methanol or ethanol with HTP, which shows consistently low ignition delay time and good hypergolic ignition performance. It also has low viscosity and comparable theoretical specific impulses compared to conventional hydrazine-based systems. This catalytically promoted hypergolic system with HTP opens up a new avenue for replacing conventional highly toxic propellants.
Article
Energy & Fuels
Haoran Zhao, Gang Li, Jinhua Wang, Zuohua Huang
Summary: In this study, the turbulent expanding flames of hydrogen/air mixtures were investigated over a wide range of equivalence ratios using a fan-stirred combustion chamber. The effects of molecular transport on turbulent flame propagation were analyzed, including flame morphology, turbulent burning velocity, and their correlations. It was found that the wrinkled degree of the turbulent flame surface was stronger under fuel-lean conditions and the flame morphology became more wrinkled as it propagated outwardly. The peak turbulent burning velocity occurred at fuel-lean conditions and the effects of molecular transport were enhanced under intense turbulent field.
Article
Mechanics
Yunfeng Bi, Haiquan Bi, Honglin Wang, Yuanlong Zhou, Ruiqi Wan, Yongliang Xie
Summary: This study proposes a full-size experimental platform for a single outlet siphon drainage system to investigate the flow characteristics of the siphon drainage. A full-scale numerical model of a siphon drainage system is established and the process of the siphon drainage is simulated using the volume of fluid model. The accuracy of the numerical model is verified by comparing its results with experimental data. Furthermore, a sensitivity analysis of different pipeline structure parameters on siphon priming time is presented, revealing that a larger length and diameter of the suspension pipe and a larger riser pipe diameter prolong the siphon formation time. Finally, theoretical formulas are derived to describe the mathematical relationships between the suspension pipe length and maximum displacement, and the suspension pipe length and siphon priming time.
Review
Engineering, Electrical & Electronic
Peng Chen, Qin Cai, Jiaen Xu, Qin Chen, Xin Su, Yongliang Xie
Summary: Noise can be found anywhere in the aerospace field and has a significant impact on aircraft operation. The control of sound emission is of great concern from economic and environmental perspectives. It is annoying for passengers and pilots, and may pose a higher risk for military applications. Additionally, sound emission can cause damage and threat to engine equipment due to strong pressure oscillations. Furthermore, combustion noise can greatly influence engine combustion process, resulting in increased emissions and lower efficiency. Therefore, noise emission measurement is crucial for aerospace research.
JOURNAL OF SENSORS
(2023)
Article
Thermodynamics
Meng Zhang, Wanying Xu, Ruixiang Wang, Xutao Wei, Jinhua Wang, Zuohua Huang, Houzhang Tan
Summary: This study investigates the effect of wall heat loss on NOx emission by designing air film cooling on the swirling combustion chamber. The flame structure and NO production were measured using OH-/NO-PLIF techniques, and NOx emission was analyzed using a Gasmet DX40 0 0 FTIR gas analyzer. Large eddy simulation with detailed chemistry was also conducted to further understand the experimental findings. The results show that wall heat loss decreases NOx emission but increases N2O emission.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Weijie Zhang, Wang Han, Jinhua Wang, Zuohua Huang, Wu Jin, Jeroen van Oijen
Summary: This study models the Darmstadt multi-regime turbulent flame MRB26b using the Flamelet-Generated Manifold (FGM) in the context of Large Eddy Simulation (LES). Different databases are used to build premixed, non-premixed, and partially premixed chemical databases, and the LES-FGM results are compared with experimental data using two sub-filter closure models. The results show that the databases lead to similar modelling of major species but better predict intermediate minor species using counter-flow flame databases. The study also reveals the over-prediction of minor species using the DTF model and proposes a correction method for improvement.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Xiao Cai, Shouguo Su, Limin Su, Jinhua Wang, Marcus Alden, Zhongshan Li, Zuohua Huang
Summary: In this study, the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames is demonstrated. It is found that intense turbulence can cause the strong burning of iron-methane hybrid mixture with separated dual-front or merged single-front structures. The formation of iron flame front is attributed to local iron concentration accumulation, enhanced heat transfer of iron particles, and mixing promotion of iron particles with oxidants by strong turbulence. Additionally, strong self-similar propagation of the hybrid flame is observed under different turbulence intensities, which is influenced by flame mode transition and differential diffusion.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Wanying Xu, Meng Zhang, Yifeng Zhang, Jinhua Wang, Zuohua Huang
Summary: This study investigates the effects of temperature and composition stratification strategies on the auto-ignition characteristics of NH3/H2/air mixtures in HCCI engines. The results show that temperature stratification can reduce the peak heat release rate, advance the ignition time, and extend the combustion duration, while composition stratification has limited effect on the overall combustion process.
APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Energy & Fuels
Ruihan Ge, Erjiang Hu, Xiaoxin Yao, Chenglong Tang, Zuohua Huang
Summary: This experimental study investigates the effects of ignition timings, injection pressures, and hydrogen enrichment on ethanol stratified ultra-lean combustion. The results show that the addition of hydrogen increases the stable ignition limit and improves combustion characteristics. However, delayed ignition timings and high injection pressures may result in incomplete combustion.
Article
Thermodynamics
Longjuan Ji, Jinhua Wang, Weijie Zhang, Deli Li, Guangya Hu, Zuohua Huang
Summary: The nonlinear behavior of thermoacoustic oscillation for premixed swirl flames fueled with CH4/air mixtures is experimentally studied. The study reveals the effects of changing equivalence ratio phi, combustor inlet bulk velocity Uin, and swirl number S on the flame modes and oscillations. The study also shows the relationship between the appearance of flame in the outer circulation zone and the occurrence of quasi-periodic and limit cycle oscillations. Furthermore, the study finds that the lean/rich blow-off limits and oscillation range are extended with a larger S, while the stable combustion regime is wider with a smaller S.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
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)