Jayaprakash Chandran - LSSBB™’s Post

Oh man, if you aim to accurately predict the so-called "pressure drop" in turbulent internal flow using CFD, something that might seem trivial at first glance (why not?), you'd better hold on tight; there are twelve terms involved in the power balance! Using Reynolds averaging, we typically derive turbulent and mean kinetic energies by taking moments of the momentum balance with conveniently selected fluctuating velocities. In an attempt to simplify, I applied Reynolds averaging to the dot product of velocity and the momentum conservation equation. This procedure appears to give a conservation law for the total macroscopic power. Interestingly, it does not include the well-known turbulence production term. This makes sense since turbulence production appears with opposite signs in the mean and turbulent kinetic energy equations. This raises a tricky question: does turbulence production really exist?. I think in some sense it does; but considering that the same reasoning can be applied to the dissipations if the internal energy of the open system is included in the balance, we must be careful in the meaning we assign to the word "exist". Continuum mechanics raises existential questions about phenomena that are not truly real, but rather the result of mathematical constructs we create to describe the motion of many tiny particles, or are they actually fields?... #CFD #TurbulentFlow

🌊🔬 Flow Visualization Techniques in Fluid Dynamics 🔬🌊 For anyone interested in fluid dynamics and experimental methods, understanding flow visualization techniques is essential. Here are some key techniques used in the field #FluidDynamics #FlowVisualization #ExperimentalMethods #ScienceAndEngineering #CFD #FluidMechanics #STEM

🔍 Unlocking Flow Dynamics Precision with Mesh Sensitivity and K-Omega SST in Mixing Elbow Pipelines 🔍 Mesh sensitivity isn't just a computational step; it's a crucial exploration shaping the accuracy of our fluid dynamics simulations. 🌊💻 Why K-Omega SST? 🤔 Despite a plethora of options, K-Omega stands out for its versatility and reliability in capturing a wide range of flow regimes, making it an ideal choice for complex systems like mixing elbow pipelines. 📏 Cell Size Matters: Varying grid resolutions reveal invaluable insights into solution convergence. Finer mesh sizes unveil the subtle nuances of flow dynamics, providing a precise depiction of system behavior. 🔄🔍 🔍 Unveiling Wall Y+: Variations in y+ values across different mesh sizes aren't mere chance; they result from heightened resolution, particularly in capturing velocity gradients near walls. These details are pivotal for predicting wall shear stress accurately and essential for understanding flow characteristics. 🌪📈 In the provided image, the 5mm cell size emerges as optimal, evident in both pathlines and wall Y+ distribution. Mesh sensitivity isn't just technical; it's a journey toward simulation fidelity. As we refine meshes and delve into flow dynamics intricacies, we gain deeper insights into complex systems. 💡 Let's refine our approaches and harness precise meshing's power in unraveling fluid mechanics mysteries. 💪🔬 #FluidDynamics #MeshSensitivity #Simulation #Engineering #LinkedInLearning

I’m excited to share that our recent research on airfoil design and performance, focusing on passive air-flow control and CFD analysis, is now available on the 𝗮𝗿𝗫𝗶𝘃 preprint portal with full access. 𝘐𝘮𝘱𝘳𝘰𝘷𝘦𝘮𝘦𝘯𝘵 𝘰𝘧 𝘕𝘈𝘊𝘈6309 𝘈𝘪𝘳𝘧𝘰𝘪𝘭 𝘸𝘪𝘵𝘩 𝘗𝘢𝘴𝘴𝘪𝘷𝘦 𝘈𝘪𝘳-𝘍𝘭𝘰𝘸 𝘊𝘰𝘯𝘵𝘳𝘰𝘭 𝘣𝘺 𝘶𝘴𝘪𝘯𝘨 𝘛𝘳𝘢𝘪𝘭𝘪𝘯𝘨 𝘌𝘥𝘨𝘦 𝘍𝘭𝘢𝘱.  DOI: https://lnkd.in/g2xJ3wE7 𝘌𝘧𝘧𝘦𝘤𝘵𝘴 𝘰𝘧 𝘛𝘳𝘢𝘪𝘭𝘪𝘯𝘨 𝘌𝘥𝘨𝘦 𝘛𝘩𝘪𝘤𝘬𝘯𝘦𝘴𝘴 𝘰𝘯 𝘕𝘈𝘊𝘈 4412 𝘈𝘪𝘳𝘧𝘰𝘪𝘭 𝘗𝘦𝘳𝘧𝘰𝘳𝘮𝘢𝘯𝘤𝘦 𝘢𝘵 𝘓𝘰𝘸 𝘙𝘦𝘺𝘯𝘰𝘭𝘥𝘴 𝘕𝘶𝘮𝘣𝘦𝘳𝘴: 𝘈 𝘊𝘍𝘋 𝘈𝘯𝘢𝘭𝘺𝘴𝘪𝘴.  DOI: https://lnkd.in/gmSxKHzq

🤔 “Where do I even begin with Fluid Dynamics & CFD?” It’s the first question we hear from engineering students and professionals alike. The answer? Start with the fundamental equations that govern our physical world. 🌊 Introducing our comprehensive guide to Essential Fluid Dynamics Equations - your roadmap from basics to mastery. 📚 What you’ll learn: - Governing Equations of Fluid Flow - The Continuity Equation (your foundation) - Navier-Stokes Equations (the heart of fluid dynamics) - Energy Equation (understanding heat transfer) - Bernoulli’s Equation (practical applications) - Euler’s Equations (ideal fluid flow) - Darcy-Weisbach (real-world pipe flow) 💡Ready to master fluid dynamics? Read more : https://lnkd.in/eM5K9HBv #FluidDynamics #Engineering #CFD #Mathematics #Tutorial #ANSYS

💥 This can be the basis of Computational Fluid Dynamics (CFD). A must-read blog about fundamentals of fluid dynamics

Combustion Instabilities and Instability Modeling ✅ Identifying Instabilities ✅ Modeling Approaches ✅ Experimental Validation ✅ ....more 👉 Fill To Interact More: https://lnkd.in/gf73E-5n #CombustionInstabilities #InstabilityModeling #FlameDynamics #Thermoacoustics #CombustionPhysics #TurbulenceModeling #AcousticResonance #EngineNoise #FlamePropagation #FluidDynamics #HeatTransfer #ComputationalCombustion #GasTurbines #RocketEngines

Bernoulli’s Equation Bernoulli’s Equation is a fundamental principle in fluid mechanics that describes the conservation of energy in a flowing fluid. It states that in a steady, incompressible, and non-viscous fluid, the sum of pressure energy, kinetic energy, and potential energy per unit volume remains constant along a streamline. The equation is expressed as: P + 1/2pV^2 + pgh = Constant Where: • P = Pressure energy (Pa) • p = Fluid density (kg/m³) • V = Fluid velocity (m/s) • g = Acceleration due to gravity (m/s²) • h = Height or elevation (m) Key Concepts: 1. Pressure Energy P: The force exerted by the fluid on its surroundings. 2. Kinetic Energy 1/2pV^2: Energy due to the fluid’s motion. 3. Potential Energy pgh: Energy due to the fluid’s elevation in a gravitational field. Applications: • Venturi Effect: Fluid velocity increases and pressure decreases as it passes through a narrow section of a pipe. • Airplane Wings: The pressure difference above and below the wing creates lift. • Flow Measurement: Devices like Venturi meters and Pitot tubes use Bernoulli’s principle to measure fluid flow velocity. Limitations: Bernoulli’s Equation assumes the fluid is: 1. Steady (no changes over time). 2. Incompressible (constant density). 3. Non-viscous (no energy losses due to friction). 4. Flowing along a streamline. In real-world situations, corrections may be needed for viscosity, turbulence, and compressibility effects.

Despite the significance of rough-wall turbulent flows in many engineering applications (e.g. leading-edge erosion of wind turbine blades), we need up-to-date review papers on the topic. However, Kadivar, Tormey, and McGranaghan (2021) give us just that—with more than 500 references spanning 175 years of research, they analyse past and recent flow studies over rough surfaces to improve our general understanding and identify gaps for future research. The paper first describes the classical division of the boundary layer into layers dominated by viscous or turbulent shear stresses and the classification of “smooth” and “rough” flow regimes using the concept of equivalent sand-grain roughness. It then outlines how roughness effects have historically been investigated experimentally and, more recently, numerically with high-resolution computational fluid dynamics (CFD). While our understanding of turbulent flows over rough surfaces is still far from comprehensive, the paper concludes that continual research and modern CFD methods, like DNS, are the pathway to improve our fundamental understanding of rough-wall flows. Get research summaries by email: https://lnkd.in/eDevB8E2   Mohammadreza Kadivar, David Tormey, and Dr. Gerard McGranaghan. 2021. “A Review on Turbulent Flow over Rough Surfaces: Fundamentals and Theories.” International Journal of Thermofluids 10 (May): 100077. https://lnkd.in/dEiSf9Hi. #windenergy #windpower #research #CFD #AndreasBechmann #windturbine #leadingedgeerosion #lercat

Transport Phenomena Alphabets-Part2: The attached movie is a part of our course on Transport Phenomena covering basis of material and energy balance, fluid dynamics, mass and heat transfer (run2 March 05- April09, 2024 https://lnkd.in/d66pkAjP) describing clear concepts of the following important items:   -What is the basic concepts behind diffusion mechanisms for transport of Mass, Momentum and Heat? -Fick, Fourier and Newton-Viscosity laws can be well understood considering movement of a ball on an inclined surface, in which the speed of ball is function of slope. The slope of concentration, temperature and velocity are discussed in this way. In this way, not difficult to deeply understand these simple equations towards Navier-Stokes Equations.   -While the base of mass and momentum diffusion is Brownian motion, that needs mobility of the molecules, for heat diffusion, this is not the case. This is why a better name can be heat conduction, as we use as well. However, thermal conduction/diffusion in fluids are influences by molecular mobility.    -Original concept of the Convective Transport Phenomena should be considered as "(Convective Mass )*Properties" which becomes "Density*Velocity*Area*Properties" for the case of fluid flow. This general concept shouldn't be mixed with the "convective heat/mass transfer at solid boundaries", which are indeed combined diffusion/conduction + convection mechanism, and not really just convective mechanism as I discussed recently (https://lnkd.in/edv2bZfJ ) Related running Supervised Live-Online Course: Basic Course on Fluid Dynamics, Heat & Mass Transport Phenomena-Run3 2024: https://lnkd.in/ea59rdP8 May 28 to July 04, 2024, (12 Lectures x 90 min, 6 Weeks, Tuesdays & Thursdays, 18:00-19:30, Berlin Time Zone). #transportphenomena #fluiddynamics #heattransfer #masstransfer #diffusion #convection #mechanicalengineering #chemicalengineering #energy #material