Article
Thermodynamics
Mingeon Kim, Dong Hwan Shin, Jin Sub Kim, Bong Jae Lee, Jungho Lee
Summary: This study investigated the effectiveness of effusion and transpiration cooling for turbine blades, with experiments conducted in a high-temperature wind tunnel. The research found that transpiration cooling achieved 34% and 25% higher cooling effectiveness compared to effusion and internal cooling respectively.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Gi Mun Kim, Jae Su Kwak, Jung Uk Choi
Summary: The experimental study showed that installing a protrusion at the slot exit of inclined film cooling slots can significantly improve film cooling effectiveness, with greater improvement observed at higher blowing ratios for 45-degree slots. The height of the protrusion was found to have a greater impact on film cooling effectiveness than the width.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Multidisciplinary Sciences
Sebastian Pitikaris, Patricia Bartz, Peidong Yu, Samantha Cristoforetti, Matthias Sperl
Summary: A three-dimensional granular gas of ellipsoids is established in the microgravity environment of the International Space Station. The cooling behavior of the granular temperature is well described by Haff's cooling law with time scale tau, and evidence of particle clustering is observed towards the end of the experiment.
Article
Thermodynamics
Mingeon Kim, Dong Hwan Shin, Bong Jae Lee, Jungho Lee
Summary: Micro cooling using micro-sized cooling holes or porous structures on the surface shows promise in cooling gas turbine blades. This study comprehensively investigated the performance of micro cooling on C3X blades by applying effusion and transpiration cooling in a cascade arrangement. The overall cooling effectiveness distribution was estimated using infrared thermometry, and the flow visualization and numerical simulation techniques were used to investigate the velocity and thermal boundary layer formation. The results showed that micro cooling performs effectively due to convective heat transfer and the reduction of heat transfer from the hot mainstream. Effusion cooling and transpiration cooling achieved an overall cooling effectiveness of 0.4 and 0.6, respectively, at a mass flow ratio of 5.3% commonly used in gas turbine cooling applications.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Nuclear Science & Technology
M. Romano, D. Pizzocri, L. Luzzi
Summary: This study proposes a modeling methodology to address the scarcity of experimental data on the combined behavior of fission gas and helium. By using a physics-based modeling approach, the study identifies the most interesting conditions for future experiments and includes a sensitivity analysis to validate the recommendations.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Thermodynamics
Jiahao Liu, Yining Fan, Manjiang Yang, Jinhui Wang, Qimiao Xie
Summary: This paper proposes an oil-immersed battery thermal management system to reduce battery temperature and improve its thermal safety. Experimental results show that insulating oils, such as transformer oil and silicon oil, have better cooling effectiveness than natural convection. The transformer oil outperforms silicon oil in terms of cooling and temperature homogenization. The feasibility of the self-designed oil-immersed battery cooling system is verified, providing guidance for the development of more efficient liquid cooling systems in the future.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Materials Science, Multidisciplinary
Enrique Abad, Santos Bravo Yuste, Vicente Garzo
Summary: This study focuses on the mean square displacement (MSD) of intruders in a freely cooling granular gas, revealing a logarithmic time dependence and complex mechanical parameter dependence.
Article
Engineering, Mechanical
Xuejie Zhang, Wei Sun, Wei Wang, Kun Liu
Summary: Granular friction behaviors were investigated during a linear reciprocating sliding process using a customized experimental apparatus. The evolution of two normal forces on the shearing unit qualitatively reflected the effects of the force chain network. The coefficient of friction reached a stable value rapidly within the initial sliding stage and remained constant, showing a significant decrease with external load and a slight increase with sliding velocity.
Article
Thermodynamics
Yide Guo, Xibing Li, Linqi Huang
Summary: Oil-based drilling fluid has a critical cooling effect on wellbore stability in deep shale reservoirs. This study conducted cooling experiments on heated Longmaxi shale samples using oil-based drilling fluid and found that anisotropic macroscopic thermal fractures occurred in the samples after cooling, with the imbibed fluid covering the bedding surfaces. The dynamic strength of the samples decreased with increasing temperature and showed a V-shaped curve with respect to bedding orientation at all temperatures.
Article
Thermodynamics
Ye Rim Jo, Young Seo Kim, Min Seok Kang, Jin Young Jeong, Hyeok Je Kim, Jae Su Kwak
Summary: This study investigates the effects of metering and diffuser length on the film cooling effectiveness of a laidback fan-shaped hole. Experimental and numerical analyses were conducted, revealing that the film cooling effectiveness increases with an increase in diffuser length. However, when the metering length exceeds a critical value, the coolant is shifted to one side of the diffusion section, resulting in a decrease in film cooling effectiveness.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
I-Cheng Huang, Kuan-Hsueh Lin, Chih-Yung Huang, Yao-Hsien Liu
Summary: Effusion film cooling is a highly effective method for cooling high-temperature turbine blades. Compared to conventional film cooling, effusion cooling provides better cooling effectiveness and coverage. Increasing the streamwise hole spacing reduces the cooling effectiveness for simple-angle designs, while compound-angle designs achieve higher effectiveness. Simple-angle holes are more sensitive to changes in turbulence intensity. Effusion cooling is also more resistant to coolant lift-off at high blowing ratios.
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2023)
Article
Engineering, Geological
Fangwei Yu, Lijun Su
Summary: This paper presents an experimental investigation of the mobility and deposition characteristics of dry granular flow. The results show that factors such as angle of slope, granular volume, cushion, granular structure, and granular size all have an impact on the mobility and deposition characteristics of granular flow. The study helps to interpret the changes in granular flow characteristics.
Article
Energy & Fuels
Orhan Kalkan, Ali Celen, Kadir Bakirci
Summary: The thermal performance of a LiFePO4 pouch type battery under different discharge rates was experimentally and numerically investigated. It was found that natural convection cooling is not sufficient for the battery at high discharge rates.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Mechanics
Yunhui Sun, Wentao Zhang, Yi An, Qingquan Liu, Xiaoliang Wang
Summary: The study investigated immersed granular collapse with initially dense packing, focusing on collapse characteristics under different flow regimes and the influence of initial aspect ratio. Results showed significant differences in collapse procedures between inertial and viscous regimes, with transitional regime exhibiting unique characteristics of both. Inertial regime demonstrated faster collapse process and sharper deposition, while viscous regime showed triangular final deposition and particle flow following fluid motion. Characteristics of collapse regime were more pronounced in higher columns.
Article
Mechanics
Manon Robbe-Saule, Cyprien Morize, Robin Henaff, Yann Bertho, Alban Sauret, Philippe Gondret
Summary: The study investigates the generation of a tsunami wave by an aerial landslide through model laboratory experiments. It is found that the collective entry of granular material into water governs the wave generation process, with the amplitude of the wave linearly scaling with the water height. The density of the falling grains has a negligible influence on the wave amplitude, suggesting that the volume of grains entering the water is the relevant parameter in wave generation.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Francesco Atzeni, Flavio Lanfranconi, Christof M. Aegerter
EUROPEAN PHYSICAL JOURNAL E
(2019)
Article
Neurosciences
Desiree Konig, Paule Dagenais, Anita Senk, Valentin Djonov, Christof M. Aegerter, Anna Jazwinska
FRONTIERS IN MOLECULAR NEUROSCIENCE
(2019)
Article
Physics, Multidisciplinary
Babak Vajdi Hokmabad, Kyle A. Baldwin, Carsten Krueger, Christian Bahr, Corinna C. Maass
PHYSICAL REVIEW LETTERS
(2019)
Article
Mechanics
Paule Dagenais, Christof M. Aegerter
JOURNAL OF FLUID MECHANICS
(2020)
News Item
Chemistry, Multidisciplinary
Corinna C. Maass
Article
Multidisciplinary Sciences
Paule Dagenais, Christof M. Aegerter
Summary: By measuring the three-dimensional flow field, the time-dependent pressure and shear stress distributions on the surface of a pitching and deforming hydrofoil are determined; the velocity vector field is determined using volumetric particle tracking velocimetry and inserted into the Navier-Stokes equation to calculate the total hydrodynamic stress tensor, verifying the time-dependence of the force; unsteady Euler-Bernoulli beam theory is used to derive instantaneous transversal force distributions based on the flexible hydrofoil's deflection, compared with the spatial distributions of hydrodynamic stresses from the fluid velocity field.
Article
Physics, Multidisciplinary
Babak Vajdi Hokmabad, Ranabir Dey, Maziyar Jalaal, Devaditya Mohanty, Madina Almukambetova, Kyle A. Baldwin, Detlef Lohse, Corinna C. Maass
Summary: This research demonstrates that autophoretic droplet swimmers can transition from quasiballistic to bimodal chaotic propulsion by controlling the viscosity of the environment. The physical mechanism behind this transition involves the droplet recurrently switching between two dominant modes due to interactions with self-generated chemical gradients, promoting self-avoiding walks.
Article
Biology
Paule Dagenais, Simon Blanchoud, David Pury, Catherine Pfefferli, Tinri Aegerter-Wilmsen, Christof M. Aegerter, Anna Jazwinska
Summary: Understanding how external factors modulate genetically encoded information to produce specific phenotypes is a key scientific interest. By manipulating the external environment of regenerating fish fins, researchers were able to induce structural and phenotypic responses. Mechanical forces were found to play a role in fine-tuning locomotory organs during fin morphogenesis.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2021)
Article
Physics, Multidisciplinary
Chenyu Jin, Yibo Chen, Corinna C. Maass, Arnold J. T. M. Mathijssen
Summary: Microswimmers can serve as efficient cargo carriers that can move deep inside complex flow networks. When a school collectively entrains the surrounding fluid, their transport capacity can be significantly enhanced, even for dilute schools. The volume of liquid entrained can be much larger than the droplet itself, amplifying the effective cargo capacity over an order of magnitude.
PHYSICAL REVIEW LETTERS
(2021)
Article
Green & Sustainable Science & Technology
Valerio Mazzone, Marcella Bonifazi, Christof M. Aegerter, Aluizio M. Cruz, Andrea Fratalocchi
Summary: Despite the decreasing cost of renewable energy compared to fossil fuels, countries are still increasing their coal-fired capacity. In order to limit global warming, coal usage should decrease by 80% within the next decade. A new approach leveraging on coal's properties has been explored, leading to the development of a highly efficient solar-driven carbon cycle for freshwater production. This innovative technology offers a sustainable solution for water scarcity while eliminating the risk of CO2 reinjection into the environment.
ADVANCED SUSTAINABLE SYSTEMS
(2021)
Article
Biophysics
Lara Selvaggi, Mirco Ackermann, Laurynas Pasakarnis, Damian Brunner, Christof M. Aegerter
Summary: This study used a unique magnetic tweezers technique to quantitatively measure the force production of Myosin II waves on the dorsal surface of Drosophila embryos. It provided quantitative values for Myosin-driven force and elucidated the dynamics of Myosin II waves, as well as characterized the mechanical properties of the dorsal yolk cell surface.
BIOPHYSICAL JOURNAL
(2022)
Article
Optics
Archana Malavalli, Christof M. Aegerter
Article
Physics, Fluids & Plasmas
Chenyu Jin, Jeremy Vachier, Soumya Bandyopadhyay, Tamara Macharashvili, Corinna C. Maass
Article
Optics
Lukas Schertel, Oliver Irtenkauf, Christof M. Aegerter, Georg Maret, Geoffroy J. Aubry
Article
Optics
Subas Scheibler, Mirco Ackermann, Archana Malavalli, Christof M. Aegerter
