Xinxin Sun’s Post

Understanding how #water is absorbed in cement-based materials is essential for predicting the long-term #durability of #concrete structures. Conventional #numerical models simplify processes by averaging #material properties and flow variables. Such methodology fails to capture the complete #microscopic details of the relevant processes, and a more profound #fundamental understanding is needed. Our recent study investigated the capillary water #imbibition processes through #DirectNumericalSimulations (DNS) of air-water #multiphase flow, directly at the #pore level. This approach solves full microscopic flow equations using fine numerical #meshes to enable detailed insight into #porescale variables and processes that are still poorly understood. A number of different features were analysed using 2D #model geometries, such as changes in the pore-sectional area, cross-flow between capillaries of different radii, or the influence of narrow throats on imbibition #dynamics and air #trapping. Considering the importance of spontaneous imbibition in a broad range of #natural and #industrial processes, the knowledge we obtain here can improve our fundamental understanding and lead to the #development and #enhancement of #macroscale (i.e. traditional) models. To know more: https://lnkd.in/eXbr8QUe Luka Malenica Zhidong Zhang Ueli Angst

An important step in understanding liquid transport in porous materials' complex microstructure.

𝗧𝗵𝗲 𝗦𝗰𝗶𝗲𝗻𝗰𝗲 𝗕𝗲𝗵𝗶𝗻𝗱 𝗖𝗮𝘀𝘁𝗶𝗻𝗴 𝗣𝗿𝗼𝗰𝗲𝘀𝘀𝗲𝘀 Casting is a manufacturing process in which a certain liquid material is coagulated into a mold of the desired shape. It is is used to form metal, plastic, ceramic parts; etc, ticking on the principles of physics, chemistry, and material science. The science behind it involves numerous processes from fluid dynamics and heat transfer to material science and computational modeling. With advancing technology in this fast-paced world, our knowledge of these fundamental principles will continue to evolve, leading to further developments and upgrades in the cast parts across diverse industries. Connect with us to know more! #JPKMetallics #casting #science

𝗔𝗱𝘃𝗮𝗻𝗰𝗶𝗻𝗴 𝘁𝗵𝗲 𝗳𝗶𝗲𝗹𝗱 𝗼𝗳 𝗖𝗙𝗗: 𝗳𝗹𝘂𝗶𝗱𝘀 𝗼𝗳 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗿𝗵𝗲𝗼𝗹𝗼𝗴𝘆 The Weissenberg effect, also known as rod climbing, is a phenomenon observed in rheology of complex fluids like polymers. This effect occurs when a viscoelastic material is subject to shear forces and rotation simultaneously. In the Weissenberg effect, a cylindrical rotating rod immersed in a viscoelastic material, such as a polymer melt or solution, starts climbing along its axis as shown in the video. From the paper: "The Weissenberg effect or rod climbing occurs due to the influence of normal stress differences in the variation of the pressure value in the radial direction. Therefore, the normal stresses may cause the total normal pressure to decrease in the radial direction (...)" Want to know the details about modeling and numerics? Have a look at this paper: https://lnkd.in/eiwVQe59 Enjoy! #CFD #simulation #technology #rheology #polymer #flow #engineering #CAE #community #sharingsiscaring Source: https://lnkd.in/eJ396FUW

Understanding rheology is key for accurate CFD modeling of non-Newtonian fluids. The Weissenberg effect is a great example. #CFD #rheology #fluids

𝗔𝗱𝘃𝗮𝗻𝗰𝗶𝗻𝗴 𝘁𝗵𝗲 𝗳𝗶𝗲𝗹𝗱 𝗼𝗳 𝗖𝗙𝗗: 𝗳𝗹𝘂𝗶𝗱𝘀 𝗼𝗳 𝗰𝗼𝗺𝗽𝗹𝗲𝘅 𝗿𝗵𝗲𝗼𝗹𝗼𝗴𝘆 The Weissenberg effect, also known as rod climbing, is a phenomenon observed in rheology of complex fluids like polymers. This effect occurs when a viscoelastic material is subject to shear forces and rotation simultaneously. In the Weissenberg effect, a cylindrical rotating rod immersed in a viscoelastic material, such as a polymer melt or solution, starts climbing along its axis as shown in the video. From the paper: "The Weissenberg effect or rod climbing occurs due to the influence of normal stress differences in the variation of the pressure value in the radial direction. Therefore, the normal stresses may cause the total normal pressure to decrease in the radial direction (...)" Want to know the details about modeling and numerics? Have a look at this paper: https://lnkd.in/eiwVQe59 Enjoy! #CFD #simulation #technology #rheology #polymer #flow #engineering #CAE #community #sharingsiscaring Source: https://lnkd.in/eJ396FUW

this is critical in predicting fluid behaviour thus critical in design of mixers

The diffusion of #moisture/water vapor, especially in applications with high-humidity service conditions, could impact the properties of #polymers and #polymercomposites. Achieving full saturation of water molecules within #thermoplastic polymers may take several months or years, contingent upon factors such as the polymer's functional groups, component geometry, and temperature. To investigate the effects of moisture on the properties of our polymeric component, crucial questions arise: "What duration of immersion is required to ensure saturation of our polymeric component in water?" and "Are there methods to expedite this process?" This is where #experimental mechanics, #analytical modeling, coupled with #CAD/FEA, becomes invaluable! Through collaboration between the #UniversityofToronto and #Flexpipe, we have developed a methodology to address these questions, which has been validated experimentally. The contours depicted below illustrate the results of this methodology, which can be applied to any geometry.

📣 It is our great pleasure to share the good news — the Special Issue "Design, Manufacturing and Properties of Refractory Materials" of Materials (IF=3.4) has now been released as a book (Reprint)! 🔥 Refractory materials are crucial for industrial and civil development. Sharing knowledge on refractories is the only way to upgrade their quality. 🌎 The authors who contributed to this Reprint by sharing their state-of-the-art research are greatly acknowledged! 🔎 This Reprint covers 18 research papers, including 1 review. It immerses the reader into the latest developments in the technology of refractory materials. From the application of Artificial Intelligence and computer-aided methods, like machine learning or image analysis and the simulation of refractories’ properties and corrosion phenomena, to tailoring the properties of refractories to be more environmentally friendly, we aim to elucidate the current global trends and progress being made in refractories technology. This reprint has been created by world-recognized researchers, representing both academia and industry, striving jointly to make refractories safer and working for longer periods of time. Feel welcome to download and read the Reprint: https://lnkd.in/dU2kMDws Thank you once again for your effort and your invaluable contribution !!! 💚

**Random Update:** Recently, I’ve been exploring metallography, the study of the microstructure of metals. To my understanding, in order to gain a lucid view of a metal’s structure at a micro level, the metal must undergo a six-step process: 1. A metal specimen is cut and applied to a grinding wheel to create a flat surface. The grinding process also removes any surface deformities. 2. After the flat surface is created, the specimen is polished using finer polishing compounds until it has a mirror-like finish. This process further removes surface defects, including abrasions left from the grinding process. 3. Next, the polished specimen is cleansed using solvents like ethanol or acetone to remove contaminants that could interfere with the etching process. 4. The etching process begins. Etching is when the polished and cleansed metal is exposed to a chemical solution that attacks certain phases or constituents of the metal. The chemical solution (etchant) chosen and the duration of etchant exposure depend on the material undergoing observation and its specific features needing to be exposed. 5. After the etchant is applied to the metal sample over a specific period of time, it is then rinsed in water or another suitable solvent and dried to prevent over-etching the material. 6. The carefully prepped material is then placed under a microscope for observation. The etching process creates visible distinctions between different material phases or constituents, providing insight into its microstructural features. I provided a link to a brief YouTube video giving a visual of the entire process if you want to check it out. To learning, Harland G.