bill clark

- Submarine Motion Monitored with CFD Software Maritime Reporter, Jan 2014 #18
The numerical simulation of submarine maneuvering is a challenging problem that has only recently been addressed by advances in Computational Fluid Dynamics (CFD) software.

In this article, we demonstrate how CD-adapco’s simulation technology can be applied to accurately predict how a submarine’s motion is driven by hydrodynamic forces, and compare numerical results with experimental data.
The physics-based simulation of a full-scale submarine performing maneuvers is an expensive proposition relative to many CFD applications. This is principally due to the wide range of length and timescales that must be resolved in order to predict accurately the flow around the submarine hull. An additional challenge involves representing the full geometric complexity of an appended submarine and propulsion unit. The length scales range from the very thin boundary layer to the full length of the submarine. The time scales range from a fraction of the propeller blade passing period to the total duration of a maneuver - more if several maneuvers are combined in a single simulation. These disparities in scale lead to very large computational meshes and simulation times that, until recently, have challenged the state-of-the-art in computational resources.
The submarine in question is propelled by a three-bladed rotating propeller. Maneuvers were executed through the application of rudder and stern planes, and controlled by varying the position of these control surfaces in response to the submarine motion predicted by the simulation.

Numerical method
During the course of a maneuver, the submarine changes its position and orientation continuously in time in response to the pressure field generated by application of the control surfaces. The simulation of a maneuver requires the coupled solution of equations of motion of the rigid body (in six degrees of freedom) with unsteady Reynolds-averaged Navier-Stokes equations (URANS). The URANS solver uses a fully-implicit iterative time-integration scheme. It computes the flow field around the body first and integrates the computed shear stresses and pressure distribution on the surface of the body, providing the hydrodynamic forces and moments acting on it. The equations of motion are then solved in order to obtain instantaneous displacements and rotations.
This information is used to update the computational mesh which is rotated and translated as a rigid body with respect to an inertial frame of reference.
The integration and rigid body mesh movement are performed automatically using CD-adapco’s Dynamic Fluid-Body Interaction (DFBI) model at each iteration. By converging this iteration process at each time step, the trajectory of the body is obtained. The implicit nature of the method (in which equations of motion are calculated simultaneously with the flow field) is important to ensure the overall stability of the simulation without using an impractically small time step.

Computational mesh
The discretized domain consisted of 3 million computational cells, including layers of prismatic cells next to the walls, which was prescribed in order to capture the near wall boundary layer. The mesh was automatically constructed using CD-adapco’s automatic hexahedral meshing methodology: a simple background hexahedral mesh was created within the boundaries of the computational domain, overlapping the geometry of the submarine. Any hexahedral cells that were located completely inside the body or the extruded layer were deleted, while those that intersect this layer were trimmed so that any overlaps were removed. Finally, the mesh was locally refined in regions where large flow variations were expected.
The propeller was enclosed inside the cylindrical mesh block that rotates about the propeller axis, with a sliding interface between the cylindrical mesh block and the surrounding fluid domain. Rudder control surface motions were accounted for by using mesh distortion. As the rudder is deflected to a new position at each time step, the mesh in this structured block is locally deformed and smoothed. By employing this procedure only a single computational mesh had to be generated for the entire simulation - rather than creating several meshes for various rudder positions and interpolating between them. Because the rudder mesh motion was integrated into the solution process, less user input was required.

Maneuvering simulations
For the case of constant heading and large depth, the submarine is assumed to be traveling through an infinite domain of stagnant water. The motion of the submarine is controlled by a three-bladed propeller, rudder and stern planes. The entire computational mesh including the submarine body is assumed to be moving with the body without any deformation. The flow field computations were performed in the inertial frame of reference, which makes the specification of boundary conditions easier. Since the body moves through infinite volume of stagnant water, the velocity specified at the far field boundaries of the computational domain is zero.
For the case of horizontal overshoot maneuvering, the top and bottom rudder surfaces were actuated to initiate the maneuver. In the experiment, the rudder was first deflected to 10 degrees and held in this position until the body reached a yaw angle of 30 degrees. The rudder was then reversed. Figure 2 shows predicted pressure distribution on walls and streamlines behind propeller. Predicted time history of roll, pitch and yaw angles show good qualitative agreement with measurements, see Figures 3 and 4.

Conclusions
Good qualitative agreement has been shown between predictions and measurements for the studied maneuvers. The results obtained demonstrate the suitability of the present methodology for the simulation of submarine maneuvers and motion of similar underwater autonomous vehicles. CFD simulation tools will help engineers to optimize the design and analysis process and improve the maneuvering capabilities, survivability and cost of submarines.

(As published in the January 2014 edition of Maritime Reporter & Engineering News - www.marinelink.com)
- Submarine Maneuvering Simulation Technology Marine Technology, Jan 2014 #18
The numerical simulation of submarine maneuvering is a challenging problem that has only recently been addressed by technological advances in commercial Computational Fluid Dynamics (CFD) software. In this article, we demonstrate how CD-adapco’s simulation technology can be applied to accurately predict how
- To the North, South And A Little Island Sheltered Maritime Reporter, Jan 2003 #27
Vessel Annual, so I traveled as far east on Long Island as possible without getting my feet wet. MR/EN stopped in to see Capt. Cliff Clark and Bill Clark, the brothers who operate the 200-year old South Ferry. As the fifth-generation of the family, the brothers manage the four-vessel fleet from their
- Willard Marine, MetalCraft Inc. Launch Hybrid Aluminum/FRP RIB Maritime Reporter, Aug 2001 #52
its heavier FRP cousin. This is a common problem for RIBs as the air collar bounces off the water surface. According to Willard's Product Manager, Bill Clark, the new concept of combining aluminum hulls with fiberglass decks, "Is the best of both worlds." It provides the most versatile platform for
- Proper Engine Maintenance Leads to Significant Cost Savings Marine News, Aug 2013 #30
monitors the condition of the oil for a number of factors including viscosity, wear metals, additives, contamination, and physical properties. Captain Bill Clark, who runs the South Ferry service, operates four ships that carry passengers across the waterways off New York’s Long Island. Captain Clark estimates

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March 2024 - Marine Technology Reporter page: 35
Figure 1 A self-righting vehicle design with buoyancy high and weight low, WHOI’s SeaBED AUV captures the attention of a pair of curious Antarctic penguins as it is deployed from the British research vessel James Clark Ross. Vehicle designers allowed for temperature reduction of battery capacity. Recharge
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April 2024 - Maritime Reporter and Engineering News page: 29
RADM PHILIP SOBECK, MILITARY SEALIFT COMMAND U.S. Navy photo by Bill Mesta/released U.S. Navy photo by Ryan Carter Rear Adm. Philip Sobeck, Commander, United States Navy’s Military Sealift Command, visits USNS Patuxent (T-AO 201) for a tour of the ship at Naval Station Norfolk, Va., November 20, 2023.
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April 2024 - Maritime Reporter and Engineering News page: 27
RADM PHILIP SOBECK, MILITARY SEALIFT COMMAND With COVID, we had to make some hard choices for our Do your CIVMARs have upward mobility? mariners because we couldn’t rotate. Many of our mariners The Navy has Sailors who become “Mustangs,” and work found other employment, and were able to use their skills
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April 2024 - Marine News page: 48
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April 2024 - Marine News page: 14
for the coming six to 12 months and that Congress thought that it addressed in the last Coast what’s being done to address them? Guard Authorization bill, the last National Defense Au- We’ve hit on some of them. If I had to take it up to a thorization Act. Unfortunately, the Coast Guard hasn’t higher
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April 2024 - Marine News page: 13
are being applied in a practical risk-based way. ize their guidance to really take that risk-based lens that We hope to see a Coast Guard Authorization Bill and we’ve talked about on cyber and other issues and make a Water Resources Development Act enacted this year. sure that it is tailored. There is
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February 2024 - Marine News page: 48
ADVERTISER INDEX Page Company Website Phone# 27 Ahead Sanitation www.aheadsanitationsystems.com (337) 330-4407 25 All American Marine www.AllAmericanMarine.com (360) 647-7602 7 Caldwell Lifting Solutions www.caldwellinc.com (800) 628-4263 9 CMA Shipping 2024 www.cmashippingevent.com Visit
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November 2023 - Marine News page: 64
ADVERTISER INDEX Page Company Website Phone# 39 Ahead Sanitation www.aheadsanitationsystems.com (337) 330-4407 29 All American Marine www.AllAmericanMarine.com (360) 647-7602 49 Arcosa Marine www.arcosamarine.com (615) 400-4373 3 C Job Naval Architects c-job.com/offshore Please visit our
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November 2023 - Marine News page: 38
impacting U.S. workers on new offshore en- headquartered in some of the wealthiest countries to utilize ergy projects. This effort was initiated by Sen. Bill Cassidy mariners from low-wage nations. When employed in our (R-La.) in February 2022 when he introduced the “Ameri- waters, these mariners are not
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November 2023 - Marine News page: 37
the CR only provides funding through November CBP writes: “Anchoring of the installation vessel to the seabed to aid 17, when hopefully a ? nal budget bill will be approved. If its installation activity, even if due to inclement weather, not, it’s déjà vu all over again. would result in a violation of
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November 2023 - Marine News page: 30
? cally for the maritime sectors, has been involved in successful testing alongside utility Southern Company, Terra Power, a business incubator tied to Bill Gates. California’s push for ‘green’ Alex Parker, managing partner at Rose Cay Maritime, which currently operates a large tug and barge ? eet, de- ployed
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November 2023 - Marine News page: 19
deduction trades. Even with these geographical restrictions, today there for the taxable year for cargo handling equipment, (3) the is more than $2.5 billion on deposit in CCF accounts held net sales or insurance proceeds from the disposition of cargo by more than 140 fundholders who own or operate vessels
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November 2023 - Marine News page: 18
NOFOs that have been issued for this tection Agency (EPA) was “taking the next step to invest $3 increased funding have emphasized the importance of dem- billion in its Clean Ports Program to fund zero-emission port onstrating that a project for which funding is requested will equipment and technology and
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November 2023 - Maritime Reporter and Engineering News page: 80
Index page MRNov23:MN INDEX PAGE 11/3/2023 1:56 PM Page 1 ADVERTISER INDEX Page Advertiser Website Phone# C2 . . . . .ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .www.eagle.org/outlook2023 . .
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September 2023 - Marine Technology Reporter page: 64
IRM services for The BSEE is funding the project with a grant to UH re- Petrobras. The project involved a remote piloting upgrade of searchers Zheng Chen, Bill D. Cook Assistant Professor of the workclass ROV system on board an ROV support vessel. Mechanical Engineering and Gangbing Song, John and Re- Real-time
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October 2023 - Marine News page: 48
ADVERTISER INDEX Page Company Website Phone# 27 Ahead Sanitation www.aheadsanitationsystems.com (337) 330-4407 19 All American Marine www.AllAmericanMarine.com (360) 647-7602 35 Appleton Marine, Inc www.appletonmarine.com (920) 738-5432 7 Clean Gulf www.cleangulf.org Visit us online 41
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October 2023 - Marine News page: 24
Feature Alternative Fuels However, the AMR notes there are no commitments now Fire Protection Association dealing with safeguards for the from any vessel owners or gas companies for H2 offtake. “generation, installation, storage, piping, use, and han- In summarizing work so far, the AMR states that
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September 2023 - Maritime Reporter and Engineering News page: 55
the economics of the tor from expensive down time and re- quality weld. Through this spectrum of weld. Chamfers are easier to create but curring repair bills. practice "where the arc meets the metal" require more weld passes to ? ll the re- Why keep making the same crack there are opportunities to create
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June 2023 - Marine News page: 48
ADVERTISER INDEX Page Company Website Phone# 35 Ahead Sanitation www.aheadsanitationsystems.com (337) 330-4407 23 All American Marine www.AllAmericanMarine.com (360) 647-7602 29 Appleton Marine, Inc www.appletonmarine.com (920) 738-5432 17 Conrad Industries www.conradindustries.
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June 2023 - Marine News page: 36
support for dredging from the Biden Administra- tion and Congress. The company highlights funding from the following: • The Omnibus Appropriations Bill for ? scal year 2023 which includes a record $8.66 billion budget for the Army Corps of Engineers’ civil works program; • Of that, $2.32 billion is
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August 2023 - Marine News page: 48
ADVERTISER INDEX Page Company Website Phone# 37 Ahead Sanitation www.aheadsanitationsystems.com (337) 330-4407 21 All American Marine www.AllAmericanMarine.com (360) 647-7602 27 Arcosa Marine www.arcosamarine.com (615) 400-4373 25 Bristol Harbor Group, Inc. www.BristolHarborGroup.com (401)
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August 2023 - Marine News page: 27
systems have both been well received by workboat crews worldwide, featuring rugged reliability, excellent headset comfort, and are built with marine-grade components of- fering ingress protection, salt/fog corrosion resistance, wide ranging temperature tolerance and superior shock/vibra- tion absorption
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August 2023 - Marine News page: 26
Feature Comms the noise. He was later informed that some had been in- systems, featuring advanced Digital Enhanced Cordless jured and even killed by propellers and jet intakes. Telecommunications (DECT) technology, provide users Months later, while visiting the home of David Clark, with all the communicati
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August 2023 - Marine News page: 25
treme altitudes, the vacuum of space, or in the realms asso- ciated with high-G ? ight,” said Dan Barry, Vice President/ Director of Research & Development at David Clark Com- pany. “Mr. Clark recognized that the unique capabilities and expertise developed by his company represented a true, National asset