Computational Simulations for Ship Design

⛵How much hydrodynamic resistance does my boat hull experience at model scale and how can I accurately scale it to a 210-meter ship? This question from MRE512 Naval Architecture III launched one of my most rewarding engineering projects yet. Instead of solving it purely on paper, I decided to take it further by building a complete CFD simulation workflow using SOLIDWORKS Flow Simulation, applying professional naval architecture principles and the ITTC-1957 resistance prediction method. 📚 COURSE QUESTION: A model 8 m long experiences 250 N resistance in Liquid C (ρ = 1010 kg/m³, μ = 0.00208 Ns/m²). The real ship is 210 m long, moving at 16 m/s in freshwater with a wetted surface area of 4100 m². Calculate: (i) Scaling factor (ii) Model speed (in knots) (iii) Reynolds number (Re) for both (iv) Ship’s resistance using ITTC (neglecting roughness). ⚙️ MY CFD PROJECT: 1. Hull Design I modeled the full hull in SOLIDWORKS 2024, using the spline and 3d sketch and surfacing into a watertight solid. I scaled the model hull to 8.0 meters using precise controls to simulate test tank conditions. 2. Simulation Setup Using SOLIDWORKS Flow Simulation, I created a full external flow analysis: Fluid: Liquid C (custom: ρ = 1010 kg/m³, μ = 0.00208 Ns/m²) Inlet Velocity: 3.12 m/s (Froude-scaled from 16 m/s) Outlet: Static pressure = 0 Pa Mesh: Boundary layer mesh with 5 layers (growth rate = 1.3), wall y⁺ optimized, local refinements on hull 3. Goals & Solving I defined Global Goals to measure: X-Direction Force (total resistance) Average Pressure Optional Drag Coefficient Each simulation ran for 500+ iterations, ensuring tight convergence and high-resolution force data. 4. Validation with ITTC-1957 Formula I manually calculated total resistance using the ITTC method: Cₓ = 0.075 / (log₁₀(Re) - 2)² R = Cₓ × ½ × ρ × V² × S Using wetted surface area from SOLIDWORKS, I compared my results with textbook predictions and they matched closely, confirming the accuracy of my simulation setup and mesh design. 🧠 What I Learned: This wasn't just about resistance, it was about engineering discipline: Scaling principles: Froude & Reynolds similarity Mesh strategy and boundary layer control Velocity and domain vector management Extracting usable design insights from simulation output Iterative testing to bridge theory with real-world results 🔍 Swipe to see: My complete hull model in SOLIDWORKS Streamlines & pressure cut plots Simulation domain & goal outputs Comparison with ITTC-based prediction 💎 As a final-year marine engineering student, I believe intuition must be backed by precision. This project gave me a taste of what it's like to think like a naval architect — from design to analysis to validation. #NavalArchitecture #MarineEngineering #CFD #FlowSimulation #SOLIDWORKS #ShipResistance #ITTC #Hydrodynamics #StudentEngineer #SimulationWorkflow #HullDesign #WettedSurface #EngineeringValidation #NavalAnalys

CFD in Submarine Design --> Understanding Propellers, Flow & Wake Signatures In underwater vehicle design, performance is not only about thrust, it is about how the entire system interacts with the surrounding fluid. From experience, one of the most challenging aspects is the interaction between hull, propeller, and wake. These are not isolated phenomena, they are strongly coupled and directly influence efficiency, noise, and even detectability. This is where CFD and CAE simulations become essential. Modern simulations allow engineers to: • Analyze propeller hydrodynamics (thrust, torque, efficiency). • Capture complex vortex structures in the wake. • Evaluate hull–propeller interaction effects. • Predict flow instabilities and their impact on performance. For example, submarine wakes are not simple flow trails, they contain coherent vortex structures (tip vortices, hub vortices) that evolve over long distances and affect both hydrodynamic efficiency and acoustic signature. The wake behind a submarine is more than a fluid phenomenon: • It influences propeller performance and stability. • It contributes to noise generation and vibration. • It defines part of the hydrodynamic and acoustic signature. Advanced CFD methods now allow tracking of the wake far downstream, revealing interactions that are difficult or sometimes impossible to capture experimentally. Capturing these effects requires: • High-fidelity turbulence modeling (LES / hybrid approaches) • Accurate representation of rotating systems • Large computational resources From a CAE perspective, understanding these flow mechanisms is key, not only to improve efficiency, but to design systems that are quieter, more stable, and more optimized from the start. The attached animation from SIMULIA highlights the wake tracking simulation of a submarine propeller (https://lnkd.in/dsd7h7S2). #CFD #CAE #Hydrodynamics #MarineEngineering #Simulation #Propeller #Multiphysics

𝗬𝗼𝘂 𝗰𝗮𝗻 𝗯𝘂𝗶𝗹𝗱 𝗮 𝘆𝗮𝗰𝗵𝘁 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝗯𝗲𝘀𝘁 𝗺𝗮𝘁𝗲𝗿𝗶𝗮𝗹𝘀... 𝗮𝗻𝗱 𝘀𝘁𝗶𝗹𝗹 𝗴𝗲𝘁 𝗶𝘁 𝘄𝗿𝗼𝗻𝗴. A yacht made entirely of carbon fiber might not perform well if not properly calculated. 𝗖𝗼𝗺𝗽𝘂𝘁𝗮𝘁𝗶𝗼𝗻𝗮𝗹 𝗙𝗹𝘂𝗶𝗱 𝗗𝘆𝗻𝗮𝗺𝗶𝗰𝘀 (CFD) in yachts. In my view, simulating a boat is even more complex than simulating a car or an airplane. Why? Because a yacht operates in 𝘁𝘄𝗼 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝗺𝗲𝗱𝗶𝘂𝗺𝘀, part of the hull is underwater, facing water pressure, while the rest is above water, exposed to wind. And it’s not just a fixed surface. The 𝗲𝗳𝗳𝗲𝗰𝘁𝗶𝘃𝗲 𝘀𝘂𝗿𝗳𝗮𝗰𝗲 𝗮𝗿𝗲𝗮 𝗸𝗲𝗲𝗽𝘀 𝗰𝗵𝗮𝗻𝗴𝗶𝗻𝗴 with load, speed, and sea conditions. Multiple simulation runs are often needed, under calm and rough waters, light and heavy loads, and different environmental conditions. Here are some important CFD use cases in yacht design: 𝟭. 𝗪𝗮𝘁𝗲𝗿 𝗙𝗹𝗼𝘄 𝗮𝗻𝗱 𝗥𝗲𝘀𝗶𝘀𝘁𝗮𝗻𝗰𝗲 (Calm vs. Rough Water) Calm water simulations are quick, but rough water takes longer due to complexity simulating how boats interact with dynamic water surfaces predicting real-world performance. CFD also helps calculate water pressure on stepped-bottom hulls, useful for estimating resistance and the max speed the hull can handle. 𝟮. 𝗣𝗿𝗼𝗽𝘂𝗹𝘀𝗶𝗼𝗻 𝗮𝗻𝗱 𝗨𝗻𝗱𝗲𝗿𝘄𝗮𝘁𝗲𝗿 𝗖𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀 CFD ensures smooth flow around propellers and rudders, preventing cavitation and ensuring air doesn’t disturb the propeller’s performance. 𝟯. 𝗦𝘁𝗿𝗮𝗸𝗲𝘀 𝗮𝗻𝗱 𝗔𝗶𝗿 𝗗𝗶𝗿𝗲𝗰𝘁𝗶𝗼𝗻 𝗖𝗼𝗻𝘁𝗿𝗼𝗹 It helps analyze the air coming from hull strakes (external longitudinal ribs), making sure it's directed properly, especially from tunnels. This helps eliminate ineffective strakes and keep only what improves performance. 𝟰. 𝗪𝗮𝘃𝗲 𝗘𝗻𝗲𝗿𝗴𝘆 + 𝗪𝗲𝗶𝗴𝗵𝘁 𝗗𝗶𝘀𝘁𝗿𝗶𝗯𝘂𝘁𝗶𝗼𝗻 For how wave energy behaves with hull areas. If harnessed well, this energy can reduce power usage and save fuel. Weight distribution is also important, it affects the center of mass and overall performance. 𝟱. 𝗜𝗻𝘁𝗲𝗿𝗻𝗮𝗹 𝗙𝗹𝗼𝘄 CFD isn’t just for the outside. It’s also valuable for internal systems like cooling, HVAC, and exhaust layout, helping ensure everything runs efficiently. 𝗧𝗵𝗲 𝗴𝗼𝗼𝗱 𝗻𝗲𝘄𝘀? Modern CAD tools now have built-in CFD modules, faster and cheaper than standalone software. Before, a rough water run took 3–4 days, and a small mistake meant starting over. Today, it’s much quicker due to the systems computing power. 𝗖𝗙𝗗 𝗺𝗮𝘆 𝗰𝗼𝘀𝘁 𝗷𝘂𝘀𝘁 𝟭% 𝗼𝗳 𝘁𝗵𝗲 𝗱𝗲𝘀𝗶𝗴𝗻 𝗯𝘂𝗱𝗴𝗲𝘁, but it delivers huge value, faster cycles, better testing, and higher performance. Small cost, big impact. #YachtDesign #CFD #NavalArchitecture #DesignOptimization

CFD Simulation for X-BOW vs. Conventional Ship Bow. 🚢 In this study, I conducted a Computational Fluid Dynamics (CFD) simulation using ANSYS to compare the performance of an X-BOW with a traditional ship bow in wave conditions. The visualization illustrates the water volume fraction and streamlines around the hull, highlighting the hydrodynamic differences between both designs. 🔹 Key Differences & Advantages of the X-BOW: ✅ Reduced Slamming: The X-BOW’s elongated and streamlined shape significantly decreases wave impact forces, enhancing comfort and structural longevity. ✅ Lower Resistance: Unlike conventional bows, the X-BOW reduces wave-making resistance, improving fuel efficiency and reducing emissions. ✅ Better Seakeeping: The design minimizes vertical accelerations, leading to smoother motion and improved operational efficiency, especially in harsh sea conditions. ✅ Enhanced Speed & Efficiency: Ships with an X-BOW can maintain higher speeds in rough seas compared to traditional hull designs. This approach is a step forward in maritime innovation, ensuring safer, more efficient, and more sustainable vessel operations. 🚀🌊 #Maritime #NavalArchitecture #MarineEngineering #ShipDesign #Shipbuilding #OceanEngineering #Seakeeping #Hydrodynamics #ShipPerformance #MaritimeTechnology #OffshoreEngineering #MaritimeIndustry #BlueEconomy #MarineInnovation #ShipResistance #WaveDynamics #ShipEfficiency #MaritimeTransport #NavalTechnology #FloatingStructures #ComputationalFluidDynamics #CFD #CFDSimulation #ANSYS #CFDModeling #FluidSimulation #NumericalSimulation #HydroSimulation #ShipHydrodynamics #MarineCFD #HydrodynamicAnalysis #WaveSimulation #CFDAnalysis #TurbulenceModeling #RANSEquations #FlowAnalysis #SimulationEngineering #MaritimeSimulation #CFDForShips #MarinePhysics #FuelEfficiency #EcoShip #GreenShipping #SustainableShipping #EnergyEfficiency #ShipOptimization #LowCarbonShipping #FutureShipping #BlueTechnology #EmissionReduction #MaritimeSustainability #ShipEnergy #Decarbonization #EcoFriendlyVessels #SmartShipping #MaritimeGreenTech #BlueInnovation #FuelConsumption #ShipHydrodynamics #MaritimeFuture #XBOW #XBOWShip

Hydrodynamics in Minutes: Hulls, Drag, Decisions . . Speed has always defined progress in maritime design, but today, speed means something very different. With the combination of advanced simulation and intelligent modeling, engineers can now predict hull resistance and flow behavior in less than a minute, achieving drag accuracy within a few percentage points of full-scale CFD. This transforms the entire design loop. Instead of waiting overnight for a single simulation, teams can test hundreds of variants in one session, adjusting form and balance in real time. What once delayed decisions for days now enables them. Consider what this makes possible: • Optimization at speed. Designers can evaluate multiple hull shapes under different conditions quickly and confidently. • Fuel efficiency improvements. Performance can be refined early, before manufacturing begins. • Operational insight. Flow behavior, stability, and control can be understood well before sea trials. When hydrodynamics becomes interactive, decisions move from reactive to predictive. Designers no longer simulate performance; they shape it. The result is not just faster modeling but faster learning. The teams that learn faster will lead the next era of maritime engineering. Key thought: Every time you shorten the feedback loop between simulation and design, you unlock a new level of innovation. #CFD #ComputationalFluidDynamics #MaritimeEngineering #NavalArchitecture #Hydrodynamics #SimulationDrivenDesign #EngineeringInnovation #DigitalTwin #DesignOptimization #AerospaceAndMarine #EngineeringSimulation #FluidDynamics #FutureOfEngineering #PhysicsBasedAI #MarineTechnology

As part of my graduation project on Marine Propeller Design, I simulated the SUBOFF underwater vehicle near free surfaces using STAR CCM++. Here’s a concise breakdown of my insights into marine CFD workflows and wave resistance analysis!  🔹Quick Overview - Goal: Analyze wave resistance at 1.1D submergence and Fr = 0.462.   - Geometry: Axisymmetric hull (L/D = 8.575).   - Key Focus: Balancing accuracy vs. computational cost in free-surface modeling.  CFD Workflow Snapshot 🔹 Meshing:   - 23 prism layers (y+ ≈ 100, stretching 1.1) for boundary layers.   - Hex-dominant trimmer mesh + anisotropic refinement (10 cells/wave height).   - Local volumetric controls for wake/free-surface refinement.  🔹 Physics:   - VOF Multiphase: HRIC scheme for sharp interface resolution (CFL = 100).   - EB-RSM Turbulence Model: Captured anisotropic flow.   - Damping Zones: 5.8m wavelength regions to suppress reflections.  🔹 Results:   - Kelvin Wave Pattern: Clear free-surface deformation.   - Resistance Force: 7% deviation from experiments (unmodeled mounts influenced discrepancy).  Lessons Learned ✅ Mesh Quality: Skewness <85° and cell quality >0.1 ensured stability.   ✅ VOF Precision: HRIC minimized numerical smearing for crisp waves.   ✅ Validation Gaps: Even small unmodeled parts impact results!  Why It’s Relevant Free-surface CFD is vital for optimizing submarine stealth, efficiency, and propeller design. Tools like STAR-CCM+ bridge virtual and physical testing, saving time/costs.   #CFD #MarineEngineering #Hydrodynamics #STARCCM #PropellerDesign