Reza Shah Mohammadi’s Post

Is Computational Fluid Dynamics (CFD) enough? 🤔 💻 Our latest article dives deep into the comparison between CFD simulations and real-world propeller testing. Discover the surprising results: https://lnkd.in/eMb65qP5 #CFD #propeller #engineering #testing #fluiddynamics Aman Basawanal

In open channel flows, hydraulic jumps represent a critical phenomenon for CFD simulations. These abrupt transitions occur when high-velocity flow encounters a zone of lower velocity. This rapid energy dissipation creates a turbulent zone with a characteristic rise in water surface level. Capturing the complex physics of the jump, including turbulence, interfacial phenomena, and energy transfer, is crucial for accurate simulations. Reliable CFD models for hydraulic jumps are essential for designing efficient spillways, stilling basins, and other hydraulic structures. The k-ε turbulence model is a popular choice for simulating hydraulic jumps in open channels due to its balance of accuracy and computational efficiency. However, it can struggle to capture the highly turbulent flow features within the jump zone. Recent research explores modifications or advanced turbulence models to improve predictions of the jump's characteristics like water surface profile and energy dissipation. This study includes a numerical model based on computational fluid dynamics to investigate the characteristics of hydraulic jumps on an open channel. It shows the contour for the volume fraction of water with a time step of 0.01 seconds and the final solution up to 40 seconds. #k_epsilon_model #CFD #hydraulic_jump #multi_phase_flows

⚡Time Dependent CFD Simulation: Vortex Shedding⚡ What is Vortex shedding in the first place? Vortex shedding is a phenomenon when the wind blows across a structural member, vortices are shed alternately from one side to the other, and where alternating low-pressure zones are generated on the downwind side of the structure, giving rise to a fluctuating force. This phenomenon is of major importance in engineering design because the alternate formation and shedding of vortices also create alternating forces, which occur more frequently as the velocity of the flow increases. Source: https://bit.ly/3nRj1Jr 📥 Latest newsletter: https://bit.ly/41N6Ixq #engineeredmind #science #technology #engineering #cfd #simulation

⚡Time Dependent CFD Simulation: Vortex Shedding⚡ Vortex shedding is a phenomenon, when the wind blows across a structural member, vortices are shed alternately from one side to the other, and where alternating low-pressure zones are generated on the downwind side of the structure giving rise to a fluctuating force. This phenomenon is of major importance in engineering design because the alternate formation and shedding of vortices also creates alternating forces, which occur more frequently as the velocity of the flow increases. Source: https://bit.ly/3nRj1Jr 📥 Latest newsletter: https://bit.ly/41N6Ixq #cfd #simulation #engineering #science

🚀 Exciting Project Update: CFD Analysis of a Crane 🚀 I recently completed a comprehensive Computational Fluid Dynamics (CFD) analysis on a crane to evaluate its aerodynamic performance under various operational conditions. The project involved: 🔍 Assessing factors such as wind load, pressure distribution, and structural stability. 🔧 Optimizing the crane's design to withstand environmental forces while maintaining structural integrity. 💡 Using the analysis results to develop design improvements that minimized drag, enhanced safety, and improved overall efficiency. This project was a fantastic opportunity to apply advanced simulation techniques and contribute to better-performing, safer, and more efficient crane designs in real-world applications. 💪🛠️ #CFD #Engineering #Simulation #CraneDesign #Aerodynamics #StructuralAnalysis #EngineeringExcellence

In this study, we developed a high-fidelity CFD simulation that addresses and overcomes the common challenges associated with modeling irregular wave and ship interactions. Typical issues such as numerical dissipation, boundary reflections, free surface deformation, and turbulence effects are mitigated through an optimized setup. By carefully calibrating numerical schemes, we minimized artificial wave damping, preserving wave energy even in long-duration simulations. Specialized boundary conditions, including well-tuned absorbing zones, were implemented to reduce reflections effectively, maintaining accurate wave characteristics throughout the domain. Additionally, a refined mesh and sophisticated free surface capturing methods ensured that wave shape and energy distribution were preserved across a wide range of wave frequencies and amplitudes. Adjustments to turbulence and viscosity models further prevented unintended energy dissipation, enabling precise representation of wave-ship interactions. This approach provides reliable, realistic results, making our simulation a robust tool for studying the complex dynamics of irregular waves and enhancing predictive accuracy in marine engineering applications. #cfd #marine_engineering #ship_building #naval_architecture #wave_energy #simulation #seakeeping

Cavitation, flash-boiling, and evaporation are among the primary phase change phenomena relevant to engineering applications. Modelling these processes in CFD has historically been challenging, particularly in capturing their inception through nucleation. A well-established test case relevant to internal flow in high-pressure fluid systems is simulated. The multiphase flow problem is tackled using Star-CCM+ software, employing the Schnerr and Sauer cavitation model within an Eulerian framework. The study consists of two sets of simulations. The first set involves a basic configuration, with three modifications in the pressure outlet boundary condition, while the second set, also with three simulations, focuses on tuning model parameters to reproduce experimental observations better. The aim is to analyze the extent of the cavitating region and compare it with experimental data under various operating conditions. Tuning of the model parameters is conducted to enhance its agreement with experimental observations. The geometry for this case is a throttle device with a U-shaped geometry with a square cross-section geometry. The inlet has a width of 300μm, an outlet of 284μm, a height of 600μm and a channel length of 1mm. The inlet rounding radius is 20μm. It is observed that the cavitation process modelled by the employed model in standard configuration is proportional to a certain extent to the one obtained in real experiments. On the one hand, the modification of the scaling factors, for certain boundary conditions, helps to replicate the experimental cavitation bubble and the pressure and velocity fields. On the other hand, these scaling factors might not be the best ones for successive simulations. The attached figure showcases the simulation's results with the scaling factors being configured for a pressure gradient of 7MPa. The additional simulations with varied pressure gradients and the same scaling factors do not match the experimental results obtained by Winklhofer, E. et al. This suggests that for each simulation corresponding to each pressure gradient, the Schnerr and Sauer scaling factors need to be adjusted to fit the experimental results. Experimental data: Winklhofer, E (2001). Comprehensive hydraulic and flow field documentation in model throttle experiments under cavitation conditions. ILASS-Europe 2001, 17 International Conference on Liquid Atomization and Spray Systems. #CFD #Simulations #Cavitation #StarCCM #Engineering #FluidMechanics

Kaplan Turbine CFD by TCAE

Benchmark calculations of #bubble_dynamics are essential for helping us learn more about complicated fluid mechanics. To make sure that theoretical models and numerical methods in the field of bubble flow dynamics are correct, the current simulation is of importance. Benchmarks help researchers figure out how accurate and reliable their computer methods are by giving them a standard against which to compare them. We checked and validated a benchmark book on bubble dynamics. The proposal paper is titled “ Proposal for quantitative benchmark computations of bubble dynamics “ [1]. [1]: https://lnkd.in/dAYSYbhK 🔽 More information: https://lnkd.in/dG-KbryD #BubbleDynamics #FluidMechanics #ComputationalFluidDynamics #Benchmarking #NumericalMethods #Simulation #ResearchValidation #TheoreticalModels #FluidDynamics #EngineeringResearch #BenchmarkComputations #ScientificResearch #CFD #FlowDynamics #Hydrodynamics #DataAccuracy #ModelValidation #FluidFlow #PhysicsOfFluids #QuantitativeAnalysis #Bubbledynamic #Ansys #Fluent #Multiphase

Turbomachinery 🔍 Turbomachinery is a very vast field in CFD that consist of analyzing systems such as compressors, turbines, fans, pumps and turbofans. The physics involved are also very broad: aerodynamics, aeroacoustics, Fluid Structure Interaction (FSI) , Conjugate Heat Transfer (CHT), and more. The level of complexity can range from full 360° unsteady LES analysis, to single stage sector steady RANS simulation with moving reference frame and mixing planes. One of the many challenges is to have a good quality mesh aligned with the flow with optimized number of cells to reduce computational time. This is usually done with a structured block mesh. On Ansys, this can be achieved with the mesher TurboGrid, while Star-CCM+ has its own integrated structured mesher. All pictures taken from simulations done by EUROCFD on Fluent and Star-CCM+. #cfd #turbomachinery #fluent #starccm