Ship Science and Engineering
Naval Architecture glossary (page 2)
The parent engineering discipline of the ship: hull geometry and hydrostatics, resistance and powering (the Holtrop-Mennen method, the Admiralty coefficient), propeller hydrodynamics and cavitation, seakeeping, maneuvering, and the design spiral. Includes structural design under the IACS Common Structural Rules, hull-girder strength and FEA, intact and damage stability under the IS Code and the Second Generation Criteria, and freeboard under the Load Line Convention.
311 defined terms.
Showing 61 on this page (page 2 of 2).
S
- Service margin
- Margin added to trial power for service conditions.
- Shaft horsepower (SHP)
- Power transmitted by the propeller shaft.
- Shallow-water effects
- Increase in resistance and squat near the bottom.
- Sheer plan
- Side view of waterlines.
- Ship motion equations (6 DOF)
- Surge, sway, heave, roll, pitch, yaw equations.
- Side-force coefficient
- Non-dimensional lateral hydrodynamic force.
- Significant wave height (Hs)
- Mean of highest one-third wave heights.
- Simulated annealing (hull optimization)
- Stochastic optimizer for hull form design.
- Slamming
- Impact loading from re-entry of bow flat into the wave.
- Slender ship theory
- Asymptotic theory for high-Fn vessels.
- Smith effect
- Pressure reduction in waves affecting wave loads.
- Sommerfeld radiation condition
- Outgoing-wave boundary condition.
- SST k-omega model
- Menter shear-stress transport turbulence model.
- Stability booklet
- Approved booklet of loading conditions and curves.
- Stagnation point
- Point of zero local velocity on a body.
- Standard wave (IACS Rec. 34)
- Standard North Atlantic wave for design loads.
- Steepest wave criterion
- Wave-breaking limit, H/L approx 1/7.
- Stockholm Agreement
- Damage stability requirement for Ro-Pax ferries.
- Strip theory
- 2D sectional approach to seakeeping (Salvesen-Tuck-Faltinsen).
- Subdivision draft
- Maximum draft for assessing subdivision and damage stability.
- Sway
- Lateral translational motion.
T
- Tank top
- Inner-bottom plating forming cargo hold floor.
- Thrust deduction fraction (t)
- (T - R)/T reduction of effective thrust on the hull.
- Tonne per centimeter immersion (TPC)
- Mass required to sink the ship one centimeter.
- Towing tank
- Long basin for resistance and self-propulsion tests.
- Transom
- Flat or curved stern surface above the waterline.
- Transverse metacenter (MT)
- Metacenter for transverse heel.
- Trim
- Difference between forward and aft drafts.
- Trim and stability booklet
- Document containing loading conditions and stability data.
- Trim moment
- MCT*trim, equivalent moment.
- Trochoidal wave theory
- Early wave theory used for hogging/sagging analysis.
- Turning circle
- Path traced by the vessel under steady rudder.
- Twin-skeg stern
- Stern with two slender skegs supporting twin shafts.
U
- Unrestricted service
- Operational notation without ocean-area restriction.
- Upper deck stringer
- Strake at the gunwale connection.
V
- Vapor pressure (water)
- Pressure at which boiling occurs, relevant to cavitation.
- Vertical center of buoyancy (VCB)
- KB, vertical centroid of displaced volume.
- Vertical center of gravity (VCG)
- KG, vertical centroid of mass.
- Vibration mode shape
- Spatial distribution of an eigenvibration.
- Voith-Schneider propeller (VSP)
- Cycloidal vertical-axis propeller.
- Volume coefficient (CV)
- Volume divided by L^3.
- Vortex lattice method
- Panel method using horseshoe vortices for foil and propeller analysis.
W
- Wageningen B-series
- Open-water propeller series from MARIN.
- Wake fraction (w)
- (V - VA)/V at propeller plane.
- Waterplane area coefficient (CWP)
- Aw/(L*B).
- Wave celerity
- Phase speed of surface waves.
- Wave drift force
- Mean second-order force in irregular waves.
- Wave-making resistance (RW)
- Resistance associated with the ship's wave system.
- Weibull distribution
- Long-term distribution used for wave-load extremes.
- Weight estimate
- Engineering rollup of structure, machinery, and outfit weights.
- Welded T-bar stiffener
- Common longitudinal hull stiffener.
- Wetted surface area (S)
- Submerged hull area used in CF*0.5*rho*V^2*S.
- Whipping
- Transient hull-girder vibration after a slam.
- Wigley hull
- Mathematical parabolic hull used as analytical benchmark.
- Windage area
- Above-water projected area used for wind force.
Y
- Yaw
- Rotational motion about the vertical axis.
- Yaw checking ability
- Maneuvering criterion for stopping a yaw rate.
- Yield buckling check
- Combined yield and buckling assessment of plating.
Z
- Zaitsevsky stability criterion
- Soviet-era weather criterion variant.
- Zigzag maneuver (10/10, 20/20)
- Standard IMO test of course-keeping ability.
- Zinc anode (sacrificial)
- Galvanic anode noted in NA weight estimate.