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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>SURFACE EFFECT SHIP HEAVE CONTROL USING A LINEAR REGULATOR DESIGN</title>
      <link>https://trid.trb.org/View/155596</link>
      <description><![CDATA[A control system was designed to attenuate vertical accelerations for the XR-3 captured air bubble type surface effect ship using linear regulator techniques applied to the simplified nonlinear equations of motion. A pressure lift-only model was used to represent the craft vertical heave motion and was linearized around the steady state operating point. Model validation was obtained through analysis of the frequency spectrum. State variable feedback was used to determine a set of optimal control gains that would reduce the magnitude of the heave acceleration during operation under simulated sea input conditions. (Author)]]></description>
      <pubDate>Mon, 16 Sep 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/155596</guid>
    </item>
    <item>
      <title>AN ANALYSIS OF HEAVE ADDED MASS AND DAMPING OF A SURFACE EFFECT SHIP</title>
      <link>https://trid.trb.org/View/166775</link>
      <description><![CDATA[The analysis presents a practical method for evaluating the added-mass and damping coefficients of a heaving surface-effect ship in uniform translation.  The theoretical added-mass and damping coefficients and the heave response show fair agreement with the corresponding experimental values.  Comparisons of the coupled aero-hydrodynamic and uncoupled analytical results with the experimental data prove that the uncoupled theory, dominant for a long time, that neglects the free-surface effects is an oversimplified procedure.  The analysis also provides means of estimating the wave elevation of the free surface, the escape area at the stern and the volume which are induced by a heaving surface-effect ship in uniform translation in otherwise calm water.  Computational procedures have been programmed in the FORTRAN IV language and adapted to the PDP-10 high-speed digital computer.]]></description>
      <pubDate>Thu, 21 May 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/166775</guid>
    </item>
    <item>
      <title>THE DAMPING AND WAVE RESISTANCE OF A PITCHING AND HEAVING SHIP</title>
      <link>https://trid.trb.org/View/158150</link>
      <description><![CDATA[This paper considers the damping and wave resistance of a thin ship which is moving in calm water with constant velocity and oscillating in pitch and heave.  The velocity potential is obtained from Green's theorem after a process of systematic linearization in terms of perturbation parameters representing the beam-length ratio and the oscillation amplitude.  An asymptotic expansion of the Green's function is derived from which the energy radiation is obtained.  The coefficients of damping and increased wave resistance are then found by separation of the energy components.  No separation of the two cross-coupling damping coefficients is obtained, however. Calculations are presented for a polynomial hull and compared with experimental data.]]></description>
      <pubDate>Wed, 15 Apr 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/158150</guid>
    </item>
    <item>
      <title>ON THE DAMPING FORCE AND ADDED MASS OF SHIPS HEAVING AND PITCHING</title>
      <link>https://trid.trb.org/View/161778</link>
      <description><![CDATA[No Abstract.]]></description>
      <pubDate>Wed, 15 Apr 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/161778</guid>
    </item>
    <item>
      <title>ADDED MASS AND DAMPING OF THE HEAVING SURFACE EFFECT SHIP IN UNIFORM TRANSLATION</title>
      <link>https://trid.trb.org/View/143555</link>
      <description><![CDATA[The analysis presents a practical method for evaluating the added mass and damping coefficients of a heaving surface effect ship in uniform translation. The theoretical added mass and damping coefficients and the heave response show fair agreement with the corresponding experimental values. Comparisons of the coupled aero-hydrodynamic and uncoupled analytical results with the experimental data prove that the uncoupled theory, dominant for a long time, that neglects the free surface effects is an over simplified procedure. The analysis also provides means of estimating the wave elevation of the free surface, escape area at the stern and the volume which are induced by a heaving surface-effect ship in uniform translation in otherwise calm water. Computational procedures have been programmed in FORTRAN IV language and adapted to the PDP-10 high-speed digital computer. (Author)]]></description>
      <pubDate>Mon, 29 Dec 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/143555</guid>
    </item>
    <item>
      <title>NOTES ON THE THEORY OF HEAVE ATTENUATION</title>
      <link>https://trid.trb.org/View/155416</link>
      <description><![CDATA[This note examines the power required for heave attenuation of SEV, using either cushion air damping or flow modulating fans. Shortage of time has prevented a complete analysis of some aspects, particularly for the modulated flow case which is of most practical interest. Power requirements have been calculated for 100% heave attenuation only in the latter case and the values obtained are naturally very large. More work needs to be done on the partial alleviation case, which is of more practical interest. (Author)]]></description>
      <pubDate>Tue, 22 Jul 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/155416</guid>
    </item>
    <item>
      <title>A REVIEW OF HOVERCRAFT DYNAMIC MOTION WITH PARTICULAR REFERENCE TO RIDE AND MANOEUVRING CHARACTERISTICS</title>
      <link>https://trid.trb.org/View/92237</link>
      <description><![CDATA[The various concepts involved in the mathematical modelling of the air cushion vehicle are discussed.  Drag implications and active methods of ride control of particular interest, are mentioned.  Finally manoeuvring controls, and full scale ride quality instruments and techniques are briefly reviewed.  Order from NSFI as No. 17397.]]></description>
      <pubDate>Sat, 15 Sep 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/92237</guid>
    </item>
    <item>
      <title>ANALYSIS OF WAVES GENERATED BY A SHIP OSCILLATING AND RUNNING ON A CALM WATER WITH FORWARD VELOCITY</title>
      <link>https://trid.trb.org/View/86853</link>
      <description><![CDATA[Wave analysis is proposed for deriving the spectrum of the unsteady wave pattern, which is generated by a ship forced to oscillate and simultaneously running with a constant forward velocity, from wave elevations measured along a line parallel to its course.  The final purpose of this wave analysis is to check the validity of the theoretical predictions in the unsteady velocity potential field around a ship when it moves in waves.  The measurement of the unsteady wave pattern around a ship is difficult compared with that of the stationary wave pattern.  A new wave measuring system is invented providing us with sufficient information from the tank test to make it possible to carry out the analysis of the unsteady wave pattern.  From the results of the wave analysis of the measured radiation wave pattern compared with the theoretical prediction we can conclude that Ogilvie-Tuck's slender body theory predicts fairly well the spectrum of radiation wave pattern.  This fact means the far field velocity potential can be predicted even in minute details by the theory.  A little interaction effect between stationary and nonstationary waves are observed.]]></description>
      <pubDate>Wed, 13 Jun 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/86853</guid>
    </item>
    <item>
      <title>COMPUTATION OF THE HYDRODYNAMIC FORCES INDUCED BY GENERAL VIBRATION OF CYLINDERS</title>
      <link>https://trid.trb.org/View/85533</link>
      <description><![CDATA[The hydrodynamic pressures created by the arbitrary deformation around the girth of a two-dimensional section are computed in a form suitable for finite-element structural analysis.  The computations are based on the panel method developed by Frank (1976) for determining the hydrodynamic forces on rigid sections.  In this method the section is approximated by straight-line segments on each of which source singularities of constant strength are distributed.  The source strengths are determined by matching the kinematic boundary condition at the center of each panel.  Frank's method is extended to treat nonrigid-body deformations of an infinite cylinder, including deformations which are also periodically varying in the longitudinal direction.  The results show that these hydrodynamic pressures are quite dependent on the shape of the deformation pattern and are extremely sensitive to the longitudinal periodicity.]]></description>
      <pubDate>Wed, 25 Apr 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/85533</guid>
    </item>
    <item>
      <title>LARGE-AMPLITUDE TRANSIENT MOTION OF TWO-DIMENSIONAL FLOATING BODIES</title>
      <link>https://trid.trb.org/View/85534</link>
      <description><![CDATA[A numerical method is presented for solving the transient two-dimensional flow induced by the motion of a floating body.  The free-surface equations are linearized, but an exact body boundary condition permits large-amplitude motion of the body.  The flow is divided into two parts: the wave field and the impulsive flow required to satisfy the instantaneous body boundary condition.  The wave field is represented by a finite sum of harmonics.  A nonuniform spacing of the harmonic components gives an efficient representation over specified time and space intervals.  The body is represented by a source distribution over the portion of its surface under the static waterline.  Two modes of body motion are discussed--a captive mode and a free mode.  In the former case, the body motion is specified, and in the latter, it is calculated from the initial conditions and the inertial properties of the body. Two examples are given--water entry of a wedge in the captive mode and motion of a perturbed floating body in the free mode.]]></description>
      <pubDate>Wed, 25 Apr 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/85534</guid>
    </item>
    <item>
      <title>APPROXIMATE EVALUATION OF ADDED MASS AND DAMPING COEFFICIENTS OF TWO-DIMENSIONAL SWATH SECTIONS</title>
      <link>https://trid.trb.org/View/76913</link>
      <description><![CDATA[Derivation of approximate formulas for determining the added mass and damping coefficients of two-dimensional, small-waterplane-area, twin-hull (SWATH) sections is described.  The added mass and damping coefficients of interest are those associated with a forced oscillation of SWATH section in heave, sway, or roll mode in a free surface.  The objective of deriving the approximate formulas for the hydrodynamic coefficients is to simplify the computation of motion of SWATH ships in waves without sacrificing its accuracy significantly.  The approximate formulas are derived based on the potential-flow theory. The damping coefficients are obtained in terms of the outgoing wave amplitudes, and the added mass coefficients are obtained by using the damping coefficients through the so-called Kramers-Kronig relations.  Within the frequency range of practical interest, the approximate formulas provide satisfactory results.]]></description>
      <pubDate>Tue, 12 Dec 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/76913</guid>
    </item>
    <item>
      <title>HYDRODYNAMIC POWER RADIATED BY A HEAVING AND PITCHING AIR-CUSHION VEHICLE</title>
      <link>https://trid.trb.org/View/74162</link>
      <description><![CDATA[The harmonic heave and pitch motion of an air-cushion vehicle traveling at a constant speed over water is studied here, with a view to determining the power radiated by the surrounding wave system.  The planform of the particular craft considered is compartmented into forward and aft subcushions, and the fluctuations of pressure in these are utilized to represent the effect of the vehicle on the water.  The usual linearized incompressible potential flow theory is used.  The calculations show that at typical Froude numbers and encounter frequencies, considerable power can be radiated in this manner, and it is generally of similar magnitude to the power required to overcome the usual steady-state wave resistance.  Surprisingly, the singularity in the linear theory that occurs at the critical speed-frequency condition was found to be extremely localized and is therefore only significant in the case of a two-dimensional pressure band, or in the case of a three-dimensional pressure patch, at low Froude numbers.]]></description>
      <pubDate>Sat, 29 Jul 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/74162</guid>
    </item>
    <item>
      <title>SEAKEEPING DYNAMICS OF A SINGLE CUSHION, PERIPHERAL CELL-STABILIZED AIR CUSHION VEHICLE</title>
      <link>https://trid.trb.org/View/73385</link>
      <description><![CDATA[A study of air cushion vehicle (ACV) motion in waves is presented for a single cushion ACV having a cellular, peripheral cell-type skirt system.  The craft is considered to be traveling at constant speed while encountering regular waves of arbitrary heading.  The dynamic equations for pitch, heave, and roll motions are derived using the cushion and cell air flow equations.  These equations are solved numerically using a digital computer.  The results are shown as frequency response curves giving steady-state motion response amplitudes as a function of encounter frequency or wavelength for fixed craft speed and wave steepness.  The theoretical predictions are then compared with experimental data taken from scale model, towing tank tests in head seas. The comparison shows good agreement for pitch motion, while heave motion damping is overpredicted.]]></description>
      <pubDate>Wed, 14 Jun 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/73385</guid>
    </item>
    <item>
      <title>CUSHIONING THE RIDE IN DEEP-SEA DRILLING</title>
      <link>https://trid.trb.org/View/58828</link>
      <description><![CDATA[Heave compensation in one form or another becomes a problem in ocean drilling as soon as the depth of water precludes the use of the jackup type of platform, resting on the ocean floor and independent of the motion of the sea.  The article discusses the design of a new type of compensator with a far greater range of sensitivity and control.  Installation on the Global Challenger took place in November 1973 and the system has proved easy to use, reliable and -- most essential -- popular with the drilling crews.]]></description>
      <pubDate>Thu, 13 Oct 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/58828</guid>
    </item>
    <item>
      <title>HEAVE AND PITCH MOTIONS IN SHALLOW WATER INCLUDING THE EFFECT OF FORWARD SPEED</title>
      <link>https://trid.trb.org/View/58840</link>
      <description><![CDATA[The problem of small heave and pitch motions of a slender ship in shallow water including the effect of forward speed is analyzed using the method of matched asymptotic expansions.  Formulae valid to first order in slenderness are given for the added-mass and damping coefficients in terms of the frequency and subcritical Froude number.]]></description>
      <pubDate>Thu, 13 Oct 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/58840</guid>
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