Orca3D Marine CFD

Why use CFD?

• Eliminate or reduce model test cost and schedule
• Improve vessel performance
• Increase customer confidence in the performance of your design
• Analyze vessels that are not appropriate for traditional parametric methods

With the Orca3D Marine CFD package, you can:

• Run resistance and self-propelled analyses for displacement and planing hulls
• Analyze monohulls and multihulls, with or without appendages
• Include any type of hull features (e.g., steps, trim tabs, etc.)
• Analyze longitudinal dynamic instability (porpoising) for planing hulls
• Compute water and air streamlines

Key benefits of the Orca3D Marine CFD package include:

• Easy to run with confidence, without the need to be a dedicated CFD specialist
• Benchmarked with proprietary and public-domain hulls, against full-scale data, model tests, and other analysis codes, with excellent results
• Fast solver; uses all cores available on the computer (up to 16 cores included in base price; additional cores available for an extra charge)
• Multiphase capability accurately models the free surface behavior
• Automated CFD volume meshing in Simerics, using Rhino surface meshes as input
• Automated setup of the domain and wave refinement zone, based on input from Orca3D
• Morphing domain grid, as the vessel heaves and pitches
• Animations of the simulation results (e.g., vessel acceleration, porpoising)
• 2D/3D display of simulation behavior including dynamic pressure, wave elevation, sinkage and trim, and more

There are two parts to the package; the Orca3D plugin for Rhino and SimericsMP CFD. You need both parts to run a CFD simulation.

The Orca3D CFD interface is included in the Analysis module (or in Orca3D Version 1 or 2, the Level 2 package). The SimericsMP CFD code is available directly from us with a 3-month, 6-month, or 12-month license, as well as intermittent licenses that allow you to activate the software on a project-by-project basis. Want to learn how Orca3D Marine CFD could improve your design process? Let us give you a live, on-line demonstration, showing how quickly you can go from your Rhino/Orca3D model to accurate, high-fidelity results! Then request an evaluation license, to see for yourself how easy it is to get accurate results.

System Requirements:

CFD software is CPU, RAM, and storage intensive.

• Operating System: Windows 7, 8.1, or 10
• Memory: At least 16 GB RAM memory, preferably spread among all of the available slots (e.g., four 8 GB chips are better than two 16 GB chips). CFD uses a significant amount of RAM during simulation computations. If you have sufficient RAM memory, having more will not make the calculations faster. However, if you run out of RAM during a simulation it will try to use your hard disk as virtual memory. This is impractical for CFD, and the simulation will appear to be frozen. 16 GB  should be sufficient for evaluating Orca3D Marine CFD and in many cases for running simulations with default grid sizes. However, when running finer grids more memory may be needed. 
• Storage: A typical simulation can use from 1-3 GB of storage. If you wish to do animations, it can be much higher (e.g., 10-15 GB)
• Processor: The commercial license will use up to 16 cores on one or more CPUs. If you have fewer cores, it will use what is available. Technically speaking Orca3D Marine CFD will run on as little as a single core, however, practically speaking we’ve found that a processor with at least 4 cores is needed to get results in a reasonable amount of time. The performance scales well with core count so that all else being equal a processor with 16 cores will be approximately three times faster than an equivalent 4-core processor. Note that the evaluation license of Orca3D Marine CFD will only make use of up to 8 cores.

EXAMPLE BENCHMARKS 

DTMB Model 5415

KCS Containership

Wave Cut Comparison

Technical Papers and Presentations

Motions and Hydrodynamics of a High-Speed Search and Rescue Vessel Based on a Time-Efficient Computational Fluid Dynamics Procedure

Master's Degree Thesis, Aalto University, Finland, 2022: Pawel Jan Beszta-Borowski

This thesis proposes a time-effective procedure for numerical prediction of the hydrodynamic performance of a small high-speed craft (HSC) for Search and Rescue (SAR) operations. Following a naval architecture review of available SAR designs, engineering physics and numerical methods for the evaluation of resistance and seakeeping are explained. A method that utilises Reynolds-Averaged Navier Stokes equations-based Computational Fluid Dynamics theory is utilised to predict calm-water resistance and wave-induced motions of a sample SAR vessel operating in regular waves. Simulations are performed using the Orca3D Marine CFD environment, utilising the Simerics CFD package. The method is validated against experimental results found in literature. The comparative study of calm-water resistance allows for analysing the influence of the hull shape on the performance of the craft. Seakeeping analysis is performed in one wave length. Head, oblique and following seas conditions are simulated. In head and oblique seas, obtained results in the time domain present periodic motions. Non-linear pitch motions are displayed, followed by amplitudes of motions calculations. High non-linearity of roll motions in oblique seas is observed. The thesis concludes that for less demanding cases, the proposed procedure offers a time-efficient method to estimate the hydrodynamic performance of the vessel with satisfying accuracy. Further research is required to optimise the method for obtaining results in following seas in an acceptable time frame.

The Simulation of Ship Maneuvering Using a RANS-Based CFD Tool

SNAME Maritime Convention 2019: Chengjie Wang, Joe Snodgrass, Hui Ding

Maneuverability is an important characteristic of a ship, which affects not only the performance during its daily operation but also its safety under urgent conditions, such as danger of collision. Currently, it draws increasing attention from naval architects during the design stage. The characteristics of hydrodynamic derivatives in maneuvering equations are traditionally obtained from towing tank experiments. In this paper, we present several numerical simulations of typical ship maneuvering using a RANS-based computational fluid dynamics tool. In order to resolve the transient phenomena properly, the explicit volume of fluid method is applied to solve the free surface. The motions of the vessel are captured through an embedded 6-DOF dynamic solver. This kind of simulation provides a more direct reference to naval architects for their design and optimization work. All simulations can be achieved with practical turnaround times on a single workstation.

A Computational Study of High-Speed Planing Hull Performance by a RANS based CFD Tool

World Maritime Technology Conference 2018: Chengjie Wang, Hui Ding, Piotr Bandyk, Lawrence Leibman, Joe Snodgrass

The planing hull form has long been employed in modern marine vehicle design. Its favorable performance in the high-speed range makes it a good candidate for powerboats, yachts, and other high-speed vessels. However, it is challenging to get an accurate and cost-effective prediction of resistance as well as dynamics, i.e., porpoising. The semi-empirical and analytic methods widely used today are based on gross hull parameters, limiting their applicability and accuracy. These methods do not provide details of the flow around the hull and cannot reliably predict dynamic instabilities such as porpoising. In this paper, we present numerical simulations of two different high-speed planing hulls using a RANS-based CFD tool, and compare the predicted sinkage, trim, resistance, and other interesting properties and behaviors with experiments. In order to resolve the transient phenomena properly, the explicit Volume of Fluid (VOF) method is applied to solve the free surface. The transient, steady, and possibly unsteady motions of the vessel are captured through an embedded dynamic solver. Good agreement is shown with experiments, including prediction of dynamics, and results can be achieved with practical turn-around times on a single workstation.

The Use of CFD Simulation in the Design of Motor Yachts and their Associated Appendages

SNAME Maritime Convention 2019: Chengjie Wang, Joe Snodgrass, George Hazen, Hui Ding

The design of high-speed vessels is always a challenging job for naval architects. The semi-empirical and analytic methods widely used today are based on gross hull parameters, limiting their applicability and accuracy. These methods do not provide details of the flow around the hull and therefore cannot be applied to some design concepts like stepped hulls. It becomes more challenging when associated appendages are used in the design, like lifting strakes, spray rails, trim tabs, ventilation pipes, etc. Those designs are usually driven by experience or a trial and error process. In this paper, we present numerical studies on multiple high-speed yachts with different appendage configurations, e.g., different layouts of spray rails and/or lifting strakes, different trim tabs, etc., to illustrate how computational fluid dynamics (CFD) can help to guide the design process. The RANS-based CFD tool, SimericsMP+, is used for all simulations and results are compared to towing tank tests and sea trial data. Significant agreement is shown with experiments, including those effects due to appendages, and results can be achieved with practical turnaround times on a single workstation.

The Prediction of the Planing Hull Resistance and Porpoising using RANS based CFD Tool

SNAME Maritime Convention 2017: Chengjie Wang, Hui Ding, Piotr Bandyk

The planing hull form has long been employed in modern marine vehicles design. Its good performance at high speed range makes it a good candidate for powerboats, yachts and high speed vessels. However, it is challenging to get accurate prediction on resistance as well as dynamics, i.e. porpoising. The semi-empirical and analytic methods widely used today are based on gross hull parameters, limiting their applicability and accuracy. These methods do not provide details of the flow around the hull and cannot reliably predict dynamic instabilities such as porpoising. In this paper, we present numerical simulations of a classical planing hull (Fridsma 1969) using a RANS based CFD tool and compare the predicted sinkage, trim, resistance, and porpoising behavior with experiments. In order to resolve the transient phenomena properly, the explicit Volume Of Fluid (VOF) method is applied to solve the free surface. The transient, steady, and possibly unsteady motions of the vessel are captured through an embedded dynamic solver. Good agreement is shown with experiments, including prediction of dynamics, and results can be achieved with practical turn-around times on a single workstation.

Orca3D Marine CFD for the MACC Simulation Grand Challenge

Multi-Agency Craft Conference 2018: Bruce Hays, George Hazen, Chengjie Wang, Larry Leibman

In this paper, we present numerical simulations of the US Navy General Purpose Planing Hull (GPPH) and a classical planing hull (Fridsma 1969) using a RANS based CFD tool, and compare the predicted sinkage, trim, resistance, and porpoising behavior with experiments. In order to resolve the transient phenomena properly, the explicit Volume Of Fluid (VOF) method is applied to solve the free surface. The transient, steady, and possibly unsteady motions of the vessel are captured through an embedded dynamic solver.  Good agreement is shown with experiments, including prediction of dynamics, and results can be achieved with practical turn-around times on a single workstation. Semi-automated meshing and setup methods are described, with the goal of allowing naval architects who are not CFD specialists to obtain consistent and reliable results.

Click animation to view full size

"We just wrapped up our engineering trials on a new design, and we are very pleased with the results. Exceedingly happy with the accuracy of the simulations as they pertained to the arrangement of some of the hull details like spray strakes and fairings, etc. We also found a high degree of correlation between simulated and full scale effects of dynamic trim appliances (interceptors and trim tabs) which allowed us to choose the right appliance for this application right out of the box instead of having to trial several different types and arrangements. We took some risks with the hull form (that we would otherwise not have) due to having the data from the simulations to back up our ideas, and those risks taken certainly resulted in a better performing boat. This particular program was a trial run for the usefulness of CFD in the design phase, and our entire organization is convinced that there is a direct benefit to the product."

- Kevin Burns
VP Design & Product Development, Back Cove Yachts and Sabre Yachts

"We at Viking have been interested in CFD for 15 years, and until now it was always just out of reach due to cost, processing requirements, and time. Orca3D Marine CFD now puts the power of CFD into our hands at a reasonable cost in both dollars and CPU requirements. The software is easy to use once you get the hang of it, and we found the training very helpful. Now we have the ability to run tank test resistance simulations any time we want, and do not have to wait for available time at the towing tank. Changes to the models can be made quickly and easily on the computer, whereas changes to our tank test model had significant limitations. Any time we have questions, the Orca3D and Simerics support is quick and to the point."

- Joe Snodgrass
N.A., Viking Yacht Company

"Orca3D Marine CFD is an amazing tool and has been a tremendous asset to my latest project. Thank you guys so much for all of your patience and help on this project. Thanks also for being pioneers with this product, and all of the work that you’ve done to bring it to a level where I can actually use it effectively. I never thought it would be this easy, and I never thought that CFD would be running on my desktop! This is a huge benefit to my boat company, my naval architecture practice, and ultimately the marine industry as a whole! Thanks to all of you for your vision and hard work in bringing incredibly useful tools to practicing naval architects."

- Rob Kaidy
VP Engineering, SeaVee Boats