Bruker Nano Surfaces & Metrology的动态

?????????????? ???????????? ?? ?????????????? ?????? ???????????????? ????????, ???????????? ????????????????????, ?????? ???????????? ???????????????? Register today ?? https://lnkd.in/eFaY-rND In this webinar, guest speaker Prof. Jackson will present his work on numerical models of mixed-lubrication cases that incorporate coupled #electromagnetic, solid, and fluid mechanics solutions as well as effects from roughness. This comprehensive approach can result in models that are powerful analytical and predictive tools for applications where contacts can be electrified, such as electric vehicles, power generation, and spacecraft. ???????? ???? ?????? ???????? ?????????????? ???? ??????????: ? The relevance of effective friction, wear, and lubrication (tribology) practices, and how surface roughness can be an important factor ? What changes and new considerations arise when an electrical current is introduced across the contacts ? How numerical models can be built to address the factors of added electrical current and multi-length-scale surface roughness ?????????????? ?????????????? ?? Robert Jackson, Ph.D. Professor of Mechanical Engineering Auburn University #EVs #tribology #Friction

? Fluid dynamics at its best! The basic #fluid mechanics principles are the continuity #equation (i.e. conservation of mass), the #momentum principle (or conservation of momentum) and the #energy equation. ???????????? ?? Follow Narges Raeisi and Ring it ?? on my profile for more technical and educational content ?????????? #mechanicalengineering #mechanical #research #fluiddynamics #fluidmechanics #flow #turbulence #aerodynamics #aerospace #automotive #cfd #cae #turbomachinery

Basic principles of fluid mechanics

?? Reynolds Number: The Key to Understanding Fluid Flow Dynamics?? Ever wondered why engineers and scientists are so fascinated by the Reynolds Number? This fundamental concept plays a critical role in fluid mechanics, helping us determine how a fluid will behave under specific conditions. The Reynolds Number Re is a dimensionless quantity used to predict the nature of fluid flow—whether it will be: Laminar Flow: Smooth, orderly flow with minimal mixing between fluid layers. Turbulent Flow: Chaotic, with eddies and swirling motions. The equation is: Re = rho*v*L/mu Where: rho: Fluid density (kg/m3) v: Flow velocity (m/s) L: Characteristic length (m), such as pipe diameter mu: Dynamic viscosity of the fluid (Pa·s) Several factors influence the Reynolds Number, and understanding them is key to predicting flow behavior: 1?? Velocity of the Fluid Faster fluid velocity increases , making the flow more likely to transition from laminar to turbulent. ?? Example: Water flowing through a narrow pipe at high speed will have a high Reynolds Number. 2?? Characteristic Length This is the dimension of the system being analyzed, like the diameter of a pipe or the chord length of an airfoil. ?? Example: Larger pipes or objects increase, leading to more turbulent flow. 3?? Fluid Density Denser fluids (like oil) tend to have higher Reynolds Numbers compared to lighter fluids (like air) for the same velocity and length. 4?? Dynamic Viscosity Fluids with higher viscosity resist flow and have lower Reynolds Numbers. ?? Example: Honey (high viscosity) exhibits laminar flow even at higher speeds, while water transitions to turbulence more easily. Why is Reynolds Number Important? Aerospace Engineering: Designing airfoils and predicting airflow over aircraft wings. Civil Engineering: Calculating flow in water channels and pipelines. Automotive Engineering: Understanding airflow around vehicles to improve aerodynamics. Biomedical Applications: Analyzing blood flow in arteries and veins. Follow Shrihari Acharya for the insightful posts #FluidMechanics #ReynoldsNumber #EngineeringConcepts #Aerospace #MechanicalEngineering #CareerGrowth

NPTEL+ Masterclass Alert: Dispersed Multiphase Flow Fundamentals Join us for an in-depth exploration of fluid dynamics led by the esteemed Prof. Balachander Sivaramakrishnan, William F. Powers Professor in the Mechanical and Aerospace Engineering at the University of Florida. Masterclass Details: ?? Dates: October 4th, 5th & 6th, 2024 ?? Timings: 7:00 PM - 9:00 PM IST ?? Topics: 1/ Basic Fundamentals of Dispersed Multiphase Flows 2/ Interphase Coupling 3/ Particle-Turbulence Interaction 4/ Computational Approaches - Fully-Resolved - Equilibrium-Eulerian - Euler-Lagrange - Euler-Euler Approaches, DNS (Direct Numerical Simulation), LES (Large Eddy Simulation) Watch the video below for a quick summary of this upcoming masterclass! Limited slots available! Reserve now: https://lnkd.in/gcZPpGia ASME (The American Society of Mechanical Engineers) #NPTEL+?#FluidMechanics?#MechanicalEngineering?#AerospaceEngineering?#IITM?#ChemicalEngineering?#DigitalEducation?#DispersedMultiphaseFlow?#FluidDynamics?#Engineering?#Science?#Learning?#DigitalEducation?#particleladenflows?#directnumericalsimulations?#scientificcomputing?#multiphaseflows?#computationalfluiddynamics

Non-dimensional numbers in Science & Engineering! We come across many non-dimensional numbers, but sometimes we don’t understand their physical significance. Dimensionless numbers can help us to analyze different systems. In an experiment there are many parameters which govern the physics. It is very difficult to assess the influence of each parameter variation. By determining the Non-Dimensional Numbers for the flow, we can reduce the number of experiments. Scale down the big model, do the experiments with the small model if non-dimensional numbers match between the model & prototype. Obtained results are independent of the units. Someone using a different system of units can still interpret the result. They can tell us the system behavior. Do you have a convection dominated flow or heat is transferring mostly by conduction or the heat diffuses quickly than the velocity? You can develop correlation of engineering parameters & dimensionless numbers. They can be used for another but similar kind of system. They can be used to normalize the variation b/w different parameters like Similarity Solution. Which dimensionless numbers have you recently been using? #mechanicalengineering?#aerospace #mechanical #aerodynamics #cfd #automotive

In a rocket engine ??????????????????, the very high speed movement of the blades can lead to the formation of vapor structures. In some critical cases, cavitation can then cause a decrease in the overall performance of the pump. In this picture, cavitation pockets appearing at the leading edge tips are captured using a thermodynamically consistent phase change approach. ?? Check the following scientific paper for more information “???????????????? ?????? ???????????????????? ???? ????? ???????????????????? ??????????????????? ???? ????????????????????” https://lnkd.in/eG2rmXcY ?? ECOGEN publication https://lnkd.in/eBfCuE3r The authors of this work are Joris Cazé, Fabien Petitpas and others. ?? Find this useful? Consider reposting, pls. #cfd #cae #fluiddynamics #fluidmechanics #engineering

As tesla said; “If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” Modal analysis is widely used to understand how objects vibrate and also, to analyze and validate designs like aircraft frame parts, wind- or gas turbine blades, vehicle chassis and bodies, bridges and any critical structure that is exposed to forces that might induce harmful or even destructive resonant frequencies without damping. During my master studies, I've prepared and presented a brief introduction on Experimental Modal Analysis and also experimentally extracted natural frequencies and mode shapes of several structural parts (eg., pre stressed beams and steel plates) under different boundary conditions. Although a presentation without proper explanation and elaboration may not be as useful as it is intended to be, I will share the file here. I hope it will be of use to you. #experiments #Experimental_Modal_Analysis #ExperimentalModalAnalysis #vibration #structures #StructuralVibration #Structural_Vibration #laboratory #ModalAnalysis #modal_analysis

That his Show, not mine Some words may describe what #ElonMusk has achieved on October 13th, 2024: Top Engineering, Physics, Materials, Aerodynamics, Aeroacoustics. There's more, for sure. As a mechanical and materials engineer, who took some aerospace engineering classes at MIT, I could try to answer some (minor) questions. But the stage doesn't belong to me. That's ##ElonMusk 's. This time I have to seat on the couch and just admire! A space rocket is a complex vehicle designed for space travel and typically consists of several main components: Propulsion System: This includes engines or motors that generate thrust, typically using liquid or solid propellants. Fuel Tanks: These store the propellant used by the engines. The design may include separate tanks for fuel and oxidizer in the case of liquid rockets. Until September 23th, we got used to see the biggest part of propulsion system coming back to earth, falling somewhere on the sea. Now the whole component returned in a controlled manner that allowed it to perfectly land at the lauching platform. We know that is not physically impossible. But how he did that? Through the use of avionics used for navigation, control, and communication, that includes computers and sensors that guide the rocket? Which kind of materials was used on the airframe that holds all the components together, and must withstand extreme temperatures and pressures during launch? In the past, recovery systems in reusable rockets, allowed parts of the rocket to return safely to Earth, such as parachutes or landing gear. Now they park as a car. That's one of the main points. Thermal Protection System that shields the rocket from the intense heat generated during ascent and re-entry. Which materials were used, and how many times they can be used again? Each component played a critical role in ensuring the success of the mission and the safety of the payload. What a great achievement!

Flow past circular cylinder between Reynolds number 100 Thousand & 5 Million! This was an experimental study of flow past circular cylinder published by H.-J. NIEMANN and N. HOLSCHER in 2003. In the table we can see a summary of different flow features around circular cylinder for a range of Reynolds number. We can see variation of mean drag coefficient, mean lift coefficient, boundary layer state, strouhal number, flow separation point on the cylinder surface etc. for the range of Reynolds number! The flow around circular cylinders still is one of the challenges in fluid mechanics. It is of great interest for practical applications, such as wind loads on cylindrical structures. The flow around a circular cylinder depends on Reynolds number, since the state of the boundary layer may be either laminar or partly turbulent. Paper Link: https://lnkd.in/gCvQk6RZ A very interesting read if Aerodynamics fascinates you! I have taken this table image from the Coursera course "Applied Computational Fluid Dynamics" published by Siemens. Course Link: https://lnkd.in/gj7uDW2X #mechanicalengineering #mechanical #aerospace #automotive #cfd #turbulence