What if SEAVIEW???

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • modelnut
    • May 2003
    • 432

    #1

    What if SEAVIEW???

    What is the SEAVIEW had been an actual submarine?

    What details would need to be added to make her more real?

    Ballast/flood vents. An anchor.

    What else?

    Since I can't go the R/C route I want my Moebius to be the best static version that I can. I am not so much worried about being absolutely faithful to the FX model. I want to build her as if she had really sailed in the '60's and '70's.

    Any suggestions???

    -Leelan
  • junglelord
    Junior Member
    • Jan 2009
    • 347

    #2
    Of course the SeaView is

    Of course the SeaView is a SSNB type sub to begin with.

    I have found the original plans on this thread

    and Seaview plans here as well.
    http://www.nimr.org/seaview.html
    and also done a search for cutaway models of the Seaview.



    One question is where are the nuclear engines located....that lead to this


    I was interested in the various design characteristics of the different subs that are available for RC.

    Since I am interested in the Seaview, I thought I would submit what I have researched about this particular sub.

    I thought I would start with work from Mr Merriman on the Seaview.

    Design Flaws and Characteristics
    Wedge shape bow and manta fins creates a downward pitch when submerged. This downward thrust can be countered with internal fixed vanes in the nicelles and also functional bow planes.

    This peculiar architecture of the Seaview also creates something else.

    A large Bow-wake = lots of drag

    (Largest ever seen by Mr Merriman)

    Certainly my own little piggyback PL Seaview on a Walmart USS Dallas showed a huge difference in bow-wake

    Surface turning radius is average for the Seaview. But submerged it has some design flaws. Yaw stability increased by cadillac fins which makes submerged turns large. However, high speed underwater turns have a roll issue called "snap-roll".

    Fast underwater turns have snap-roll due to the cadillac fins which is countered by the manta fins and according to Mr Merriman the sub would actually be non-functional without the manta fins.

    the manta-fins produce a counter torque (outboard rolling moment, counter of the vehicles turn) that works to negate the de-stabilizing inboard torque produced by the SEAVIEW's sail and 'V' shaped 'Cadillac' fins at the stern. The manta-fins contribute to the dynamic roll stability of the SEAVIEW in a tight turn. As the submarines angle of attack about the yaw (turning) axis increases, and starts to 'skid' into a turn, a situation occurs at the manta-fin tips (those tips well below the vehicles longitudinal center of rotation) where the inboard manta-fin tip begins to generate an upward moment (force) and the outboard manta-fin tip produces a downward moment. These two forces induce a torsional moment that works to right the boat in the turn; the manta-fins improve the boats roll stability dynamically in a turn.

    The significant maneuverability problems with this boat occur as a consequence of a turn while submerged. Sea-trails taught me to 'ease' the SEAVIEW into high speed submerged turns. To put the rudder hard over while running at any significant speed rolls the boat into an uncontrollable dive to the bottom. (American LOS ANGELES class attack submarines have the same problem). Other than that, and the SEAVIEW's woefully poor backing down ability, it handles pretty much like any other r/c submarine.

    The only vice I can lay at the feet (fins) of the manta-fins is that they work to de-stabilize the boat in the pitch plane and contribute a great deal of flow and wave-making drag. The fix was to install permanent vanes within each propulsion nozzle, their job to direct the exhausted water upward, countering the pitching moment at the bow. In water tests verified that the fixed vanes countered the bow induced pitching problem throughout the SEAVIEW's speed regime, net angle change as a consequence of submerged speed was zero. Mission accomplished!

    But, keep in mind that the two pitching forces (shape of the hull forward, the fixed vanes in the nozzles aft) are directed down; the net force on the vehicle is a downward one. However, this downward force acting on the submerged submarine is of low magnitude and is easily countered by operating the boat at a slight up-angle or simply by cranking in a bit of 'rise' on the sailplanes.

    After installation of the fixed vanes in the nozzles depth control of the SEAVIEW became no more difficult than driving a 'traditional' type r/c submarine.

    The SEAVIEW, as an r/c submarine, can be made to be dynamically stable in pitch and yaw as it travels submerged - without need of non-scale 'stabilizing' fins or control surfaces.
    Some nice practical information on the dynamics of modern submarines and how that relates to the Seaview in particular.

    [quote]Nearly all modern American combat attack submarines employ a set of downward canted (anhedral) stabilizers at the stern (situated between the horizontal surfaces and lower rudder). Their primary function is to serve as foundations from which either evasion devices or towed cables are launched or streamed clear of the propeller/pump-jet disc. The secondary purpose of the stern mounted anhedral stabilizers is to generate a torsional force (created as the boat's angle of attack about the yaw axis increases) to counter the boats tendency to roll inboard in a turn. On a 'real' submarine this unwanted inboard rolling moment originates solely with the sail and a big reason that today's submarine sail structures are kept as short and low of area as possible. Sail structures are either well faired in to the hull (as practiced by the Russian 'Ruben' design bureau) or are so shaped as to limit the structures ability to produce lateral 'lift' at a high yaw angle of attack (American LOS ANGELELS class).

    With the SEAVIEW we are cursed with three surfaces that produce a unified torsional moment in a turn]


    Hope that stimulates some ideas.

    Comment

    • crazy ivan
      SubCommittee Member
      • Feb 2003
      • 659

      #3
      Leelan,
      I share your philosophy of

      Leelan,
      I share your philosophy of modeling the concept boat, rather than the shooting minatures. The front and back covers of Issue 15 of the Subcommittee Report feature the Seaview illustrated with exactly the type of realistic external details you are looking for. Here are some low res samples to give you the idea. You will need to purchase the actual back issue for the full res version.



      sigpic
      "There are the assassins, the dealers in death. I am the Avenger!" - Captain Nemo

      -George Protchenko

      Comment

      • scott t
        Member
        • Feb 2003
        • 880

        #4
        Since the front fins are

        Since the front fins are called Manta fins how about changing there action
        to rotate up and down horizontally removing the up or down force when
        moving forward. Manta rays move there fins up and down for propulsion.

        -Scott

        Comment

        Working...
        X