<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <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>
    </image>
    <item>
      <title>COMPUTATION OF UNSTEADY VISCOUS FLOW WITH APPLICATION TO THE MIT FLAPPING HYDROFOIL EXPERIMENT</title>
      <link>https://trid.trb.org/View/447250</link>
      <description><![CDATA[A time-accurate unsteady viscous-flow method is validated through calculations and comparisons with the Massachusetts Institute of Technology flapping-foil experiment.  Solutions are obtained using a small domain surrounding the foil, a tunnel domain that included the foil and the tunnel walls, and a complete domain that included the foil and both the tunnel walls and the upstream flappers.  In the lattter case, the CHIMERA overlaid-grid method was used.  The solutions give similar overall agreement with the data for both steady and unsteady flow, which demonstrates that such problems can be handled with a variety of formulations, although the boundary data, cpu time, and storage requirements are different. The physics are complex with analogy to Stokes layers and explicated through analysis of the axial pressure downstream travelling waves over the foil and in the near wake and in the intermediate wake, respectively, due to non-linearities induced by the convective acceleration and steady/unsteady interactions.  The nature of the unsteady displacement thickness suggests viscous- inviscid interaction as a possible mechanism for the axial gradient response.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/447250</guid>
    </item>
    <item>
      <title>TIME ACCURATE INCOMPRESSIBLE NAVIER-STOKES SIMULATION OF THE FLAPPING FOIL EXPERIMENT</title>
      <link>https://trid.trb.org/View/447251</link>
      <description><![CDATA[A numerical simulation of an experiment conducted at Massachusetts Institute of Technology has been performed.  The experiment was designed to study the flow about a two-dimensional hydrofoil undergoing high reduced frequency gust loading.  The gust was created by two NACA 0025 hydrofoils oscillating sinusoidally in phase upstream of the stationary foil.  Experimental data was taken in the flowfield near the stationary foil as well as on the foil on the entire experimental domain, including the multiblock unsteady incompressible Navier-Stokes algorithm based on artificial compressibility.  A comparison of the pressures and velocities on the bounding  box and surface of the stationary foil are presented for the steady case, as well as time histories and an harmonic analysis at the same locations for the unsteady case.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/447251</guid>
    </item>
    <item>
      <title>AN INTEGRATED PROPULSION-LIFT-CONTROL DESIGN FOR LARGE HIGH SPEED HYDROFOIL CRAFT</title>
      <link>https://trid.trb.org/View/447351</link>
      <description><![CDATA[An innovative design concept for large hydrofoil craft that can operate at high speed (>60 kt.) without detrimental cavitation is described.  The design concept overcomes the classical limits of the "square-cube" law, and provides practical foil dimensions and configurations for large size hydrofoil craft (1,000 tons and greater). The basic foundation for the concept is based on the use of a circulation control jet foil design, with ease of control of lift forces. Integration of the foil system with a unique propulsion system that supplies the necessary jet flow completes the design, which has applied ideas from aerospace industry applications.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/447351</guid>
    </item>
    <item>
      <title>MODEL SCALE EFFECTS ON A 16-309 FLAPPED HYDROFOIL SECTION</title>
      <link>https://trid.trb.org/View/161990</link>
      <description><![CDATA[Wind and water tunnel tests have been conducted of a NACA 16-309 section with the standard a = 1.0 camber line and equipped with a 25% flapchord ratio, simple, sealed flap. Differences between test results from the two facilities are discussed, as well as the effect of placing roughness strips near the leading edge.  Results are given showing the dependency of force, moment and, in particular, cavitation inception on Reynolds number over the range from 1.25 x 10 to the 6th power to 4.0 x 10 to the 6th power. (Author)]]></description>
      <pubDate>Thu, 12 Mar 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/161990</guid>
    </item>
    <item>
      <title>SECTION DESIGN FOR HYDROFOIL WINGS WITH FLAPS</title>
      <link>https://trid.trb.org/View/86859</link>
      <description><![CDATA[The basic problem of a flapped NACA-16 foil is its poor pressure distribution around the flapped region.  With the flap deflected, the velocity distribution becomes a very unfavorable shape in terms of cavitation-inception and boundary-layer separation.  This type of flowfield results in low flap effectiveness.  Based on the present profile design and boundary-layer calculation methods, improved hydrofoil wings with flaps have been developed.  The approaches to construct the desired velocity distributions to delay cavitation and boundary-layer separation are discussed.  Examples are given for the case that the flap deflection has to compensate the vertical component of the surface wave motion in a seaway.]]></description>
      <pubDate>Wed, 13 Jun 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/86859</guid>
    </item>
    <item>
      <title>HYDRODYNAMIC LOADING COEFFICIENTS FOR THE AGEH-1 MAIN STRUT-POD-FOIL SYSTEM AS DERIVED FROM THE 1975 FLAP INCIDENCE CONTROL EXPERIMENT</title>
      <link>https://trid.trb.org/View/82855</link>
      <description><![CDATA[As part of an investigation into minimizing control power requirements for hydrofoil craft, a technique has been developed for obtaining complete hydrodynamic lift and moment characteristics of a flapped hydrofoil from equilibrium data obtained in flap incidence control experiments with a freely pivoting foil. This method employs a simple mathematical model and various crossplots of the data to separate the effects of camber, foil incidence angle, and flap angle using a minimum amount of data. Existing model data for the AGEH-1 main strut-pod-foil system under subcavitating conditions have been analyzed by this method, and effects of depth and velocity are described. Velocity effects were attributed to air and/or water flow out of the pod. Relatively high values of flap lift effectiveness (0.3 to 0.4) were obtained. Centers of pressure (lines of action) for lift due to camber, angle of attack, and flap angle are presented. Recommendations are given for improving the accuracy of the measurement and analysis techniques. (Author)]]></description>
      <pubDate>Sat, 26 May 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/82855</guid>
    </item>
    <item>
      <title>A SUPERCAVITATING HYDROFOIL WITH MECHANICAL AND JET FLAPS BENEATH A FREE SURFACE</title>
      <link>https://trid.trb.org/View/80793</link>
      <description><![CDATA[The flow around a supercavitating hydrofoil equipped with both mechanical and jet flaps, moving beneath a free surface, was analyzed by second-order theory, and the method of matched asymptotic expansions was used to solve the governing integro-differential equation.  Hydrodynamic forces which are valid up to the second order of small angles of foil incidence and of jet deflection are determined by asymptotic expansions in terms of the jet-momentum coefficient.  Moreover, it is found that Oba's correction factors are not reasonable.]]></description>
      <pubDate>Sat, 13 Jan 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/80793</guid>
    </item>
    <item>
      <title>HINGE MOMENT REDUCTION FOR THE AG(EH) MAIN STRUT-POD-FOIL ASSEMBLY BY USE OF TRAILING EDGE TABS</title>
      <link>https://trid.trb.org/View/63953</link>
      <description><![CDATA[Hydrodynamic loading on a 1/12th scale model of the AG(EH) main strut-pod-foil was experimentally examined at various velocities, depth of hydrofoil submergence, strut-pod pitch angles, and foil angles of attack.  The results, which are in agreement with previous experiments, show that the lift center of pressure at zero angle of attack for this particular foil (aspect ratio = 3, taper ration = 0.3, and leading edge sweep angle - 0.724 rad or 41.5 deg) is located at 70 to 90 percent of the mean geometric chord.  Thus, the experimental results could not be compared directly to the empirical two-dimensional theory that was developed since it had been assumed that this lift acted at midchord.  Various families of fixed tab/flaps were added to the trailing edge of the foil to determine the effectiveness of such tab/flaps in reducing the foil pitching moment around the foil hinge. It was shown that such tab/flaps can significantly reduce this moment but at a drag penalty.  For example, for the particular strut-pod-foil system evaluated, to reduce the moment to zero would result in a 12 to 15 percent increase in drag. (Author)]]></description>
      <pubDate>Wed, 16 Feb 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/63953</guid>
    </item>
    <item>
      <title>A VALIDATION STUDY OF THE MIXED FOIL CONCEPT FOR HIGH SPEED HYDROFOILS</title>
      <link>https://trid.trb.org/View/30729</link>
      <description><![CDATA[A hydrodynamic validation study of the concept of the mixed foil has been carried out.  A mixed foil is a streamlined hydrofoil equipped with a flap or other device which, above a certain speed, can be activated so as to change the flow around the foil into a supercavitating flow.  At takeoff and at moderate speeds, a mixed foil is operated as a subcavitating foil; at high speeds, it is operated as a supercavitating foil.  During high speed operations, a reduction in the wetted planform area of a mixed foil is proposed.  Two hydrofoils which have as their sections plano-convex foils of thickness to chord ratios of 5% and 6% are used for the study.]]></description>
      <pubDate>Wed, 21 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/30729</guid>
    </item>
    <item>
      <title>PERFORMANCE OF A SUPERCAVITATING JET-FLAPPED HYDROFOIL AT ARBITRARY SUBMERGENCE</title>
      <link>https://trid.trb.org/View/35285</link>
      <description><![CDATA[The flow around an arbitrary supercavitating jet-flapped hydrofoil operating at an arbitrary submergence is analyzed by a second order theory and the following results are obtained; The hydrofoil performance data are shown for various submergences and jet operating conditions.  The flap effects are highly dependent on the submergence as well as the hydrofoil shape.  Operation of the jet flap results in an increase in the cavity thickness so that the hydrofoil thickness can be increased.  Especially at the shallower submergences, the performance as well as the flow pattern changes strikingly.]]></description>
      <pubDate>Tue, 18 Nov 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/35285</guid>
    </item>
    <item>
      <title>FIRST AND SECOND-ORDER THEORY ON A SUPERCAVITATING HYDROFOIL WITH A JET FLAP</title>
      <link>https://trid.trb.org/View/20770</link>
      <description><![CDATA[The basic relations for an infinite steady flow around thin hydrofoil with a jet flap are obtained as the solution of the Riemann-Hilbert-Poincare problem, and the first and second-order problem at small incidence and small deflection angle of the jet is analytically solved by means of the matched asymptotic expansions in the case of the jet-momentum coefficient small.  Expressions for lift, drag, pitching-moment, and the cavity shape have been obtained as the asymptotic expansions in powers of the jet-momentum coefficient together with its logarithm.  From the comparison of the lift with numerical results of Ho, the analytical method in this paper is seen to be very useful and reasonable.]]></description>
      <pubDate>Tue, 31 Dec 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/20770</guid>
    </item>
  </channel>
</rss>