Article
Chemistry, Physical
Kaikai Li, Yingxi Xie, Biao Tang, Huanwen Ding, Xiaokang Mei, Min Yu, Chunbao Li, Longsheng Lu
Summary: By constructing surface microstructures and improving their hydrophobicity, severe adhesion of biological fluids on surgical electrodes can be effectively reduced. Inspired by purple orchid leaves with self-cleaning properties, the dynamic behavior of water and biological droplets on superhydrophobic microstructured surfaces (SMSs) heated over 100°C was studied. The SMSs with Cassie-Baxter state showed a pseudo-Leidenfrost effect for water droplets, and the dynamic evolution mechanism of plasma droplets on heated surfaces was proposed. The findings contribute to understanding the anti-adhesion mechanism of surgical electrodes at the microscopic level.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Physical
Dmitry V. Zaitsev, Dmitry P. Kirichenko, Oleg A. Kabov, Vladimir S. Ajaev
Summary: Experimental studies and mathematical models were used to investigate the levitation of microscale droplets over an evaporating liquid layer, showing the dependence of levitation height on droplet size. The experimental data for various conditions collapsed onto a single curve predicted by the model.
Article
Chemistry, Physical
Georg Schnell, Christian Polley, Robert Thomas, Stephan Bartling, Johannes Wagner, Armin Springer, Hermann Seitz
Summary: In this study, the researchers used a customized instrument to investigate the lateral adhesion forces on femtosecond laser-structured surfaces. They found that the droplet motion was significantly influenced by the chemical and topographical surface features. The droplet mobility was classified into static, transfer, and kinetic regimes, which is crucial for designing surfaces with extreme wetting characteristics.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Luis Ruiz Pestana, Teresa Head-Gordon
Summary: The evaporation mechanism of nanodroplets is different from that of macroscopic water droplets. Regardless of hydrophobicity, the evaporation rate of nanodroplets does not follow the traditional mode and their evaporation behavior is characterized by non-equilibrium wetting. The vapor concentration on the surface of nanodroplets does not reach a steady state. The evaporative lifetime of nanodroplets is directly related to the hydrophobicity of the substrate.
Article
Physics, Multidisciplinary
Jing Lou, SongLin Shi, Chen Ma, CunJing Lv, QuanShui Zheng
Summary: In this study, a new wetting state called the suspended penetration wetting state was identified, where the droplet can penetrate the micropillars on textured surfaces without touching the base. Experimental results showed that the droplet can spontaneously recover to the initial wetting state when the external pressure is removed.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2021)
Article
Chemistry, Multidisciplinary
Seok Kim, Woo Young Kim, Sang-Hoon Nam, Seunghang Shin, Su Hyun Choi, Do Hyeog Kim, Heedoo Lee, Hyeok Jae Choi, Eungman Lee, Jung-Hyun Park, Inho Jo, Nicholas X. Fang, Young Tae Cho
Summary: The study focused on directionally controlling particle aggregation in drying droplets by investigating contact line dynamics and geometrical gradients on microstructured surfaces. Robust particle capture surfaces were designed to inhibit contact transfer of particles, demonstrating significant reduction in particle aggregates with the use of engineered microcavity surfaces. Findings suggest that the proposed microstructured surfaces have the potential to reduce indirect fomite transmission of highly contagious agents through respiratory droplets.
Article
Thermodynamics
Shinan Chang, Haifeng Qi, Shu Zhou, Yinglin Yang
Summary: A water droplet freezing experiment platform was designed to study the freezing process of droplets on different surfaces. The results showed that the nucleation temperature range of the superhydrophobic surface was larger than that of the hydrophilic surface at the same cooling rate. On the superhydrophobic surface, the number of bubbles in the water droplets increased with the freezing rate. The volume factor of the droplets on the hydrophilic surface significantly increased at the initial stage of freezing, while on the superhydrophobic surface, it gradually increased with time. The freezing time of droplets on the superhydrophobic surface decreased faster with surface temperature compared to the hydrophilic surface. The error between theoretical and experimental values of freezing time was small, with a maximum error of only 9.05%.
APPLIED THERMAL ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Guinuan Pan, Zhihai Jia, Huweihang Ding, Chenyang Zhang, Jiao Wang
Summary: This paper investigates the manipulation of droplet motion using gradient wettability surfaces. Experimental results show that curved topography has a better guiding effect on the droplet spreading direction, while gradient wettability has little effect on the spreading diameter of the droplet.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Nanoscience & Nanotechnology
Soumei Baba, Kenichiro Sawada, Kohsuke Tanaka, Atsushi Okamoto
Summary: This study focused on the hierarchical nano/microstructure of Euphorbia myrsinites leaves and successfully mimicked the structure artificially to provide important insights for the development of new engineering materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Thermodynamics
Bikash Pattanayak, Sarath S. Lal, Hardik B. Kothadia
Summary: This study analyzes droplet evaporation on aluminum and copper substrate and studies the instantaneous heat transfer coefficient (HTC) during evaporation of 100 mu l de-ionized water. The effect of substrate and fluid temperature on droplet evaporation is analyzed, and it is observed that the evaporation rate is higher for copper than aluminum. A user-friendly interface is developed for determining the instantaneous surface area of an evaporating droplet.
HEAT TRANSFER ENGINEERING
(2023)
Article
Physics, Applied
Kaikai Li, Yingxi Xie, Biao Tang, Min Yu, Huanwen Ding, Chunbao Li, Longsheng Lu
Summary: This study investigated the evolution of blood plasma droplets on a superhydrophobic microstructured surface under direct-current (DC) and alternating-current (AC) electric fields. The results showed that bubbles produced by papillae on the superhydrophobic surface under DC electric field effectively prevented directional adsorption of plasma proteins, while the AC electric field induced oscillations in plasma proteins, resulting in decrease in adhesion.
APPLIED PHYSICS LETTERS
(2022)
Article
Thermodynamics
Shinan Chang, Haifeng Qi, Shu Zhou, Yinglin Yang
Summary: In this study, the freezing characteristics of water droplets on different surfaces were experimentally investigated. The results showed that different materials have different effects on the freezing characteristics of water droplets. Superhydrophobic surfaces exhibited a better anti-freezing performance compared to hydrophilic surfaces. Additionally, the observed singular jet phenomena indicated that surface temperature significantly affects the freezing rate of water droplets.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Yue Ma, Huang Zhang, Qianfeng Liu
Summary: This study experimentally investigates the spreading and splashing behavior of continuous droplets impinging on a heated wall under different conditions. The spreading parameters of the droplets and the relationship between splashing parameters, droplet Weber numbers, and Jacob numbers are analyzed and mathematically fitted.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Junchao Wang, Xiahui Gui, Guosheng Li, Yijun Cao
Summary: This study comprehensively investigated the interaction process between water droplets and three minerals and found that the interaction forces were influenced by the wettability of mineral surfaces and impact distance.
Article
Engineering, Chemical
Hyeon Woo Son, Jung Bin Yang, Dong Rip Kim
Summary: Demisters with high water separation efficiencies are crucial for performance enhancement in thermal desalination. Microstructured surfaces inspired by nature have shown potential to significantly increase water separation by enhancing water capturing and transporting features. However, there is still a lack of experimental investigation on the performance enhancement of demisters with these functional surfaces.
Article
Nuclear Science & Technology
Koung Moon Kim, Ji-Hwan Hwang, Somchai Wongwises, Dong-Wook Jerng, Ho Seon Ahn
NUCLEAR ENGINEERING AND TECHNOLOGY
(2020)
Article
Thermodynamics
Kanit Aroonrat, Lazarus Godson Asirvatham, Ahmet Selim Dalkilic, Omid Mahian, Ho Seon Ahn, Somchai Wongwises
Summary: The investigation found that the evaporative heat transfer coefficient of R-134a in dimpled tubes is significantly influenced by the dimpled depth, but less affected by the helical pitch and dimpled pitch. Experimental results provided a range for the heat transfer enhancement factor and pressure drop penalty factor, along with proposed correlations for predicting Nusselt number and friction factor during evaporation in dimpled tubes.
HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Dong Ho Nguyen, Koung Moon Kim, Thi To Nguyen Vo, Gyu Hyeon Shim, Ji Hoon Kim, Ho Seon Ahn
Summary: In this study, electroless plating of nickel, copper, and silver was used on stainless steel 316 plate heat exchangers to enhance their thermal-hydraulic efficiency. Optimized process parameters were determined for improving surface properties and reducing mass loss, leading to a significant increase in performance as indicated by various evaluation criteria.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Su Cheong Park, Moo Hwan Kim, Dong In Yu, Ho Seon Ahn
Summary: The study investigated the effects of wall temperature, micro-pillar array size, and micro-pillar height on the outcomes of a single water drop impinging onto a heated surface with micro-pillar arrays. Micro-pillar arrays can lead to explosive lift-off behavior and increase the Leidenfrost temperature.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Hawatchai Keawkamrop, Lazarus Godson Asirvatham, Ahmet Selim Dalkilic, Ho Seon Ahn, Omid Mahian, Somchai Wongwi
Summary: This study experimentally investigates the performance of crimped spiral fin-and-tube heat exchangers with a small tube diameter. The results show that the fin pitch and outer diameter have significant effects on the heat transfer characteristics and friction factor. Correlations between the Nu, j, and f are proposed for designing heat exchangers in the thermal industry.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Review
Thermodynamics
Dong Ho Nguyen, Ho Seon Ahn
Summary: This paper discusses the methods of improving heat exchanger thermal-hydraulic efficiency through micro/nanoscale surface modification techniques. The results show that modified surfaces have great potential in enhancing heat transfer efficiency in heat exchangers by inducing turbulence and fluid mixing.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Kitti Nilpueng, Mehrdad Mesgarpour, Lazarus Godson Asirvatham, Ho Seon Ahn, Omid Mahian, Somchai Wongwises, Ahmet Selim Dalkilic
Summary: The study investigated the effects of different shapes, orientations, and distances on the air flow and heat transfer characteristics inside plate pin fin heat sinks. Results showed that under the same area, square pin fin heat sinks had higher heat transfer coefficient and pressure drop compared to circular pin fin heat sinks, while decreasing the distance led to an increase in heat transfer coefficient and pressure drop.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Chang Hun Lee, Somchai Wongwises, Dong-Wook Jerng, Ho Seon Ahn
Summary: The breakup mechanism of microbubbles in a 2D channel was studied through visualization experiments using a venturi-shaped nozzle. Increasing the rear-end exit angle of the nozzle led to smaller bubble sizes but also the formation of wake flow above 20 degrees. Analysis revealed that air bubbles interacted with the central flow and split into pieces. The use of a flare-shaped diffuser improved bubble breakup performance compared to a linear exit angle, specially in conditions with a water flow rate of 35 L/min and an air flow rate of 0.1 L/MIN.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Parinya Kiatpachai, Thawatchai Kaewkamrop, Mehrdad Mesgarpour, Ho Seon Ahn, Ahmet Selim Dalkilic, Omid Mahian, Somchai Wongwises
Summary: This paper presents the air-side performance of embedded and welded spiral fin and tube heat exchangers. The experiment results show that the fin pitch has no effect on the air-side performance of embedded spiral fin and tube heat exchangers, but it does influence the air-side performance of the welded ones. The embedded spiral fin and tube heat exchanger has a higher heat transfer rate due to better fin base connections, while the pressure drop of the welded spiral fin and tube heat exchanger is greater.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Kittipong Sakamatapan, Mehrdad Mesgarpour, Omid Mahian, Ho Seon Ahn, Somchai Wongwises
Summary: The experimental results showed that as the water flow rate increased, the airflow rate also increased, resulting in smaller but more numerous microbubbles.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Mehrdad Mesgarpour, Kittipong Sakamatapan, Ahmet Selim Dalkilic, Rasool Alizadeh, Ho Seon Ahn, Somchai Wongwises
Summary: This study investigates the flow pattern and thermal behavior of constructal theory-based pore-scale porous media (CTPSPM) using computational fluid dynamics (CFD) and machine learning. A novel hybrid computational method is developed to predict the flow pattern and thermal behavior based on high-fidelity numerical simulation. The results show that a multiblock neural network can significantly reduce computational costs and that the constructal theory has a significant impact on heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Dong Ho Nguyen, Boyeon Kweon, Jae -Sung Kwon, Taewan Kim, Somchai Wongwises, Ho Seon Ahn
Summary: This article introduces an innovative plate heat exchanger design that utilizes symmetric airfoil profile corrugation, resulting in reduced pressure drop and improved heat transfer performance. A parametric study is conducted to determine the optimal geometric configuration.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Multidisciplinary
Thi To Nguyen Vo, Dong-In Yu, Ho Seon Ahn
Summary: A practical approach to designing 3D porous materials with new functionalities for oil spill clean-up attracts widespread attention. The carbonized seaweed-coated melamine sponge (CMS) can selectively absorb oil immediately due to its countless pores using capillary-driven force to absorb oil. The microstructure and behaviors of the CMS are thoroughly investigated in relation to the unique porous structure, mechanical stability, wetting response, and in-depth processing of the high-speed visualization experiment to determine its promising abilities. The theoretical models proposed based on quantitative analysis of optically analyzed oil interface phenomena are shown to be a reliable approach for describing volumetric absorption rate and effective CMS thickness. It is expected that this research will hold tremendous potential strategies for environmental remediation.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Thi To Nguyen Vo, Sun Taek Lim, Ji Hoon Kim, Gyu Hyeon Shim, Koung Moon Kim, Boyeon Kweon, Miyeon Kim, Chang Yeon Lee, Ho Seon Ahn
Summary: This study demonstrates the synthesis of graphene materials with interconnected pore networks and shows their high efficiency in removing volatile organic compounds. The unique structure of the graphene materials has a significant impact on the removal performance.
Article
Chemistry, Multidisciplinary
Ji Hoon Kim, Gyu Hyeon Shim, Thi To Nguyen Vo, Boyeon Kweon, Koung Moon Kim, Ho Seon Ahn
Summary: This study analyzed the structure and chemistry of GO products by considering parent graphite sources and different oxidation methods. The oxidation level of GO was characterized by monitoring the C/O and sp(2) carbon ratio from XPS spectra.
Article
Nuclear Science & Technology
Orestes Castillo-Hernandez, P. E. Manuel Perdomo-Ojeda, C. R. Grantom, Pamela F. Nelson
Summary: Incorporating specified safety and production targets during the design phase can reduce costs and enhance the competitiveness of nuclear power plants. This paper presents two methods for proposing unavailability targets for nuclear reactor systems to optimize the design features. The methods are applied to a hypothetical facility, providing a basis for future work on estimating design alternatives affecting unavailabilities.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Qinjun Fu, Andre Bergeron, Philippe Fillion, Yohan Davit, Michel Quintard
Summary: In normal operating conditions, the flow within a pressurized water reactor (PWR) core primarily moves in the axial direction along the fuel rods. However, in accidents situations, transverse flows can have a significant impact on the thermal-hydraulic properties of the core. This study develops macroscopic pressure drop models for different flow directions and Reynolds numbers and validates them by comparing with existing system code results.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Xiang Chai, Xinyue Liu, Chaoran Guan, Tengfei Zhang, Xiaojing Liu
Summary: Micro nuclear reactors have gained attention for their high efficiency and long lifetime, making them suitable for remote and off-grid locations. This study examines the effects of burnable poisons on the performance of a micro nuclear reactor and improves the design for reactivity control. The computational results show that burnable poisons reduce excess reactivity and power peaking factor without significant impact on core lifetime.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Liwei Chen, Cong Zhou, Yu Wang, Yiran Zong, Tingting Lu, Chunhua Chen
Summary: This paper proposes an autonomous search method for leakage sources in nuclear emergency rescue based on the updated Infotaxis method. By considering factors such as radioactive decay and wet deposition, the method improves search efficiency and accuracy. Experimental results show that the method is particularly effective in searching for leakage sources under high emission rates and provides scientific information for early emergency response and consequence assessment.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Kirill S. Dolganov
Summary: This paper is the first part of a summary overview of IBRAE's work on the severe accident at Unit 1 of Fukushima Daiichi Nuclear Power Station. It focuses on the integral model of Unit 1 and its qualification with available data, including the comparison of simulation results with measurements for the initial phase of the accident. Important issues discussed include the direct modeling of isolation condenser performance and verification of the possibility to use an integral approach to estimate the nuclide inventory in the core.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
F. Feria, C. Aguado, J. Benavides, J. Benavides, R. Canencia-Hernanz, M. Cristobal-Beneyto, J. Fernandez Garcia, H. Galan, C. Gonzalez, A. Hernandez-Avellaneda, L. E. Herranz, G. Jimenez, L. Martinez, J. C. Martinez-Murillo, A. Milena-Perez, A. Palacio Alonso, J. Penalva, R. Plaza, D. Perez-Gallego, L. Rey, N. Rodriguez-Villagra, J. Ruiz-Hervias, J. Saiz de Omenaca Tijero, P. Vinas-Pena
Summary: The Spanish R&D efforts in dry interim storage of spent nuclear fuel mainly focus on supporting safety under storage and transportation. Experimental and modelling activities are carried out to understand and predict the fuel response, with major outcomes being improvements in the characterization of dry stored fuel, essential for safety assessment of the back-end fuel cycle.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Ang Li, Yuqing Chen, Yuxian Rao, Qi Cai, Cong Wang
Summary: This paper focuses on the boiling heat transfer model of mini-channels casing-pipes once-through steam generator (MCOTSG). By calibrating and analyzing the different nucleate boiling heat transfer models based on steady state experimental results, the secondary loop heat transfer characteristics and overall operating characteristics of OTSG under feedwater flow rate reduction are simulated. The results can provide a basis for the safety analysis and optimal design of MCOTSG and small modular reactor under low flow rate conditions.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Shu Soma, Masahiro Ishigaki, Satoshi Abe, Yasuteru Sibamoto
Summary: In this paper, the analytical wall function approach was applied to analyze the condensation flow of steam/air mixtures, and good predictions were obtained through CFD analysis.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Jinho Song, Sungjoong Kim
Summary: In this study, a machine learning platform is proposed to assist operators in diagnosing the progression of severe accidents and predicting key parameters using long short term memory networks and MELCOR simulation data. The platform shows reasonable accuracy in predicting both similar and unseen test data, as well as lost signals and key parameters for accident management.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Liang Zhao, Zhengbai Chang, Chulin Mai, Hong Ran, Jin Jiang
Summary: This study investigates the dynamic characteristics, valve disc motion, and flow field of a nozzle check valve under different spring stiffness and fluid deceleration rates. Experimental tests and numerical simulations were performed to analyze the effects on various parameters during the dynamic closing process of the valve. The results provide insights for the optimization design of check valves and more accurate calculation of their dynamic characteristic curves.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Xun Lan, Yanbo Jiang, Dan Sun, Wenbo Liu, Wenjie Li
Summary: In this study, a three-dimensional phase-field model was developed to investigate the evolution of intergranular bubbles during irradiation. The study examined the dependency of bubble percolation on bubble shape, fission rate, and average grain size. The simulation results revealed the significant effects of these factors on the shape of GB bubbles, the percolation rate, and the connectivity threshold of GB bubbles.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
J. M. S. Mendes, A. Heimlich, A. M. M. De Lima, F. C. Silva
Summary: An algorithm for solving the constitutive equations of the fourth-order Nodal Expansion Method (NEM) in parallel using GPU with quadratic transverse leakage has been proposed. The algorithm, implemented in CUDA language, showed comparable accuracy and reduced execution time compared to the CNFR code. This algorithm and the developed program have potential use in the optimization process of nuclear fuel reload patterns.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
M. Jafari, H. Jafari, M. H. Choopan Dastjerdi, J. Mokhtari
Summary: This study investigates the ability of the PGNAA facility of the Isfahan MNSR reactor to measure boron concentration in solution samples. A measurement system model is developed using Monte Carlo calculation, and a cadmium sheet is used to reduce the effect of boron in the shield. The accuracy of the model is verified through experimental tests, resulting in a calibration curve.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Ibrahim Gad-el-Hak, Njuki Mureithi, Kostas Karazis, Brian Painter
Summary: This study investigates the risk of fluidelastic instability induced by degraded baffle-former bolts in a nuclear fuel assembly. Experimental results show that the stability threshold of the mock-up array strongly depends on the relative position of the jet flow with respect to the array centerline, and axial flow velocity also has a significant effect on the jet-induced instability.
NUCLEAR ENGINEERING AND DESIGN
(2024)
Article
Nuclear Science & Technology
Yuhang Niu, Scolaro Alessandro, Carlo Fiorina, Hao Qin, Gauthier Lazare, Yingwei Wu, Wenxi Tian, G. H. Su
Summary: This paper presents the incorporation of DNB prediction into the GeN-Foam code, which is based on OpenFOAM. The accuracy of GeN-Foam in modeling DNB conditions in PWR was assessed through validation against experimental data and other codes. The results show that GeN-Foam exhibits good performance in simulating two-phase flow boiling conditions and accurately predicts the occurrence of DNB.
NUCLEAR ENGINEERING AND DESIGN
(2024)
