<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>GENERALIZED CULVERT DESIGN DIAGRAM. TECHNICAL NOTE</title>
      <link>https://trid.trb.org/View/541152</link>
      <description><![CDATA[The features of culvert flow in a basic arrangement are highlighted.  Four fundamental flow types may be identified, namely critical flow, uniform flow, gated flow, and pressurized flow.  A generalized design diagram is presented for the circular barrel that gives the possible transitions between various flow types.  Further, the lengths of free surface flows with a central pressurized flow portion are determined as a function of the pipe Froude number.  Photographs of model tests illustrate the complex flow patterns that may occur even in a simple culvert arrangement.  Of particular relevance are choking conditions and features of two-phase flow in a culvert.  The effects of friction coefficient, bottom slope, relative pipe length, and upstream head are detailed for free culvert outlet conditions.]]></description>
      <pubDate>Wed, 11 Nov 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/541152</guid>
    </item>
    <item>
      <title>RESISTANCE VARIABLES FOR SHEET FLOWS ON PORTLAND CEMENT CONCRETE SURFACES</title>
      <link>https://trid.trb.org/View/572768</link>
      <description><![CDATA[The purpose of this study was to develop reliable hydraulic resistance variables for sheet flow runoff on Portland cement concrete surfaces.  Present highest state of the art is a multiple regression equation for hydraulic flow depth without a fundamental resistance variable.  Both uniform flow and rainfall-runoff situations were investigated.  Experimental research was performed using artificial rainfall equipment on Portland cement concrete surfaces.  Three surface roughness defined by mean texture depths (MTDs) of 0.010, 0.027 and 0.044 inches were tested at each of three slopes (S) of 0.005, 0.015 and 0.025.  The uniform flow rates used ranged from very low flows up to approximately the largest flow rate possible without the development of roll waves.  A total of 73 data sets, the consequence of approximately 3300 data points, was determined from uniform flow testing.]]></description>
      <pubDate>Fri, 11 Jul 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/572768</guid>
    </item>
    <item>
      <title>SYNCHRONIZATION OF VORTEX SHEDDING FROM AN OSCILLATING CYLINDER IN UNIFORM FLOW</title>
      <link>https://trid.trb.org/View/480519</link>
      <description><![CDATA[The hydrodynamic forces acting on a circular cylinder forced to oscillate transversely in a uniform flow were measured, and the effect of synchronization of vortex shedding on the forces were examined. The vortex shedding frequency fu becomes   of the frequency of cylinder oscillation fa   2fs where fs is the natural vortex shedding frequency so called Strouhal frequency.  This phenomena is called 'frequency demultiplication'.  The measured velocity field by means of the image measurement technique showed the vortex shedding process in the case of frequency demultiplication, and the measured results show that two vortices which have the same vorticity direction shed in one and half cycle of the cylinder oscillation.  The measured hydrodynamic forces, drag and lift, were analyzed by the FFT technique.  The lift force contains a low frequency component fv0, the component lower than fa under frequency component fu0, the component lower than fa under frequency demultiplication.  However the ratio of fu0/fa is not   neither  , but continuously changes   and .  The drag force has two components beside the fa.  It is found that the drag force has the component of fu0 + fa and fu0 - fa from the analysis of measured hydrodynamic forces.]]></description>
      <pubDate>Thu, 27 Mar 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/480519</guid>
    </item>
    <item>
      <title>UNIFORM FLOW PAST ONE (OR TWO IN TANDEM) FINITE LENGTH CIRCULAR CYLINDER(S)</title>
      <link>https://trid.trb.org/View/479586</link>
      <description><![CDATA[The problem of uniform flow past one (or two in tandem formation) finite length circular cylinder(s) is investigated experimentally in this paper.  For the case of flow past a single finite length cylinder, it is found that the flow that separates from the free end interacts strongly with those that separate from the sides and results in a three-dimensional flow.  This separated flow from the free end delays the interaction between the separated flows from the sides, resulting in a less negative wake pressure and a lower drag when compared with flow past an infinitely long cylinder.  Spanwise effects were found to be stronger over the longest (h/d = 8) cylinder is investigated, with the spanwise drag coefficient increasing towards the free end.  Vortex shedding with some regularity can be detected only at y/h = 0.95 and y/h < 0.5 (with weak spectral peak) of the h/d = 8 cylinder, with corresponding Strouhal numbers equal to 0.08 and 0.191, respectively.  For the flow past two tandem finite length circular cylinders, although the transition from reattached flow to co- shedding flow is still observed, due to the highly three-dimensional nature of the flow, the change no longer takes place over the entire span simultaneously.  When the dimensionless spacing between the cylinders increases from one (cylinders touching), the co-shedding flow structure was first detected near the free end and its extend later expands towards the mounted end with further increase in cylinders spacing, at the expense of the reattached flow region.  At very small spacing between cylinders, a third flow structure which is characterised by having lower surface pressure over the windward part of the downstream cylinder was also observed.  Spanwise variation of the drag that acts on both cylinders was observed.  The magnitude of the drag coefficient was found to be strongly dependent on the flow structure involved and normally varies as a direct consequence of the variation in the wake pressure.  The overall trend is that of higher local drag towards the free end.]]></description>
      <pubDate>Wed, 12 Mar 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/479586</guid>
    </item>
    <item>
      <title>UNIFORM FLOW PAST ONE (OR TWO IN TANDEM) FINITE LENGTH CIRCULAR CYLINDER(S)</title>
      <link>https://trid.trb.org/View/467797</link>
      <description><![CDATA[The problem of uniform flow past one (or two in tandem formation) finite length circular cylinder(s) is investigated experimentally in this paper.  For the case of flow past a single finite length cylinder, it is found that the flow that separates from the free end interacts strongly with those that separate from the sides and results in a three-dimensional flow.  This separated flow from the free end delays the interaction between the separated flows from the sides, resulting in a less negative wake pressure and a lower drag when compared with flow past an infinitely long cylinder.  Spanwise effects were found to be stronger over the longest (h/d = 8) cylinder is investigated, with the spanwise drag coefficient increasing towards the free end.  Vortex shedding with some regularity can be detected only at y/h = 0.95 and y/h < 0.5 (with weak spectral peak) of the h/d = 8 cylinder, with corresponding Strouhal numbers equal to 0.08 and 0.191, respectively.  For the flow past two tandem finite length circular cylinders, although the transition from reattached flow to co- shedding flow is still observed, due to the highly three-dimensional nature of the flow, the change no longer takes place over the entire span simultaneously.  When the dimensionless spacing between the cylinders increases from one (cylinders touching), the co-shedding flow structure was first detected near the free end and its extend later expands towards the mounted end with further increase in cylinders spacing, at the expense of the reattached flow region.  At very small spacing between cylinders, a third flow structure which is characterised by having lower surface pressure over the windward part of the downstream cylinder was also observed.  Spanwise variation of the drag that acts on both cylinders was observed.  The magnitude of the drag coefficient was found to be strongly dependent on the flow structure involved and normally varies as a direct consequence of the variation in the wake pressure.  The overall trend is that of higher local drag towards the free end.]]></description>
      <pubDate>Mon, 04 Nov 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/467797</guid>
    </item>
    <item>
      <title>ON THE INSTABILITY OF A FULL NON-PARALLEL FLOW - KOVASZNAY FLOW</title>
      <link>https://trid.trb.org/View/455028</link>
      <description><![CDATA[The local instability of a full non-parallel flow is investigated. The basic flow is a horizontal uniform flow about a vertical array of periodic bound eddies.  This flow was found by Kovasznay as an exact solution to the Navier-Stokes equations.  The problem is formulated as an initial value problem with two sets of complete orthogonal functions.  A new approach to the problem with semi- infinite domain is given computationally with a new modified rational Chebyshev function.  The linear stability analysis of the Kovasznay flow is performed with respect to the odd-rational Chebyshev mode and the even-rational Chebyshev mode for the evolution of disturbances.  While symmetrical vortex sheets appeared through the process of big eddies breaking into small eddies in the odd-rational Chebyshev mode, the von Karman vortex street phenomena is found in the even-rational Chebyshev mode.  The mode corresponding to antisymmetric velocity perturbation is found to be far more unstable than symmetric disturbance.  An organized structure is developed after the onset of instability.  Several general characteristics of non- parallel flow stability are discussed.]]></description>
      <pubDate>Wed, 28 Feb 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/455028</guid>
    </item>
    <item>
      <title>CALCULATION OF NONLINEAR WATER WAVES AROUND A 2-DIMENSIONAL BODY IN UNIFORM FLOW BY MEANS OF BOUNDARY ELEMENT METHOD</title>
      <link>https://trid.trb.org/View/435071</link>
      <description><![CDATA[In this paper nonlinear wave making phenomena around a 2-dimensional body is studied. The analysis uses the boundary element method based on Cauchy's integral theorem and the wave profile is calculated by time marching integration based on the semi-Lagrangian approach. Steepening or Breaking waves can be simulated by this scheme. Two problems are discussed, a semi-circular mound in shallow water and a floating body with semi-infinite length. In cases including a uniform flow component, numerical treatments have some difficulties. In the semi-circular mound problem, nodal points on the free surface move out of the calculation region and in the floating body problem, nodal points concentrate in front of the bow. In the present work, numerical difficulties caused by these problems are settled and numerical examples are given for several cases.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/435071</guid>
    </item>
    <item>
      <title>EXPERIMENTAL STUDY OF PRODUCTION RISERS IN STEADY UNIFORM FLOW</title>
      <link>https://trid.trb.org/View/437061</link>
      <description><![CDATA[Results from an experimental investigation on sectional models of multitude risers are presented. A single cylinder was tested as a reference case. The data outlined herein contain new information about the hydrodynamic behaviour of various riser bundles exposed to a steady current. The bulk of the experimental data is pertinent to the measured steady drag coefficients and the transverse and in-line motions of such risers. Data are also provided about the influence of turbulence, surface roughness and the separation distance between the centre and satellite pipes on the loading and response characteristics of the specific riser geometries tested. It was found that when flexibility in the transverse and in-line directions of the test cylinders is allowed, large increases in both the steady drag coefficients and response amplitudes may occur compared to fixed cylinders. These increases were seen with varying intensity in both the subcritical and critical flow regimes.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/437061</guid>
    </item>
    <item>
      <title>A STUDY ON VORTEX SHEDDING FROM SPHERES IN A UNIFORM FLOW</title>
      <link>https://trid.trb.org/View/438080</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438080</guid>
    </item>
    <item>
      <title>AN AXISYMMETRIC MODEL OF SEPARATED FLOW ABOUT A SPHERE USING DISCRETE VORTICES</title>
      <link>https://trid.trb.org/View/438968</link>
      <description><![CDATA[A procedure for the calculation of the starting flow around a sphere in a uniform stream is presented. The flow field is simulated by a flow of ideal fluid with embedded vorticity. With the assumption that the flow remains symmetric, the vorticity field is approximated by a number of discrete circular line vortices. The image vortices to satisfy the boundary condition for the normal component of velocity on the surface of the sphere are determined by Butler's sphere theorem. The Stokes stream-function is used for the field description. The motion of vortices is tracked by the vortex-in-cell method, the cells being formed by square grids.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438968</guid>
    </item>
    <item>
      <title>OBLIQUE IMPACT OF TWO CYLINDERS IN A UNIFORM FLOW</title>
      <link>https://trid.trb.org/View/439826</link>
      <description><![CDATA[The oblique motion of a circular cylinder through an inviscid and incompressible fluid, conveyed by a uniform flow at infinity, in the vicinity of another cylinder fixed in space is considered. In a relative polar co-ordinate system moving with the stream, the kinetic energy of the fluid is expressed as a function of six added masses due to motions parallel and perpendicular to the line joining the centres of the cylinder pair.  The Lagrange equations of motion are then integrated for the trajectories of the moving cylinder.  In order to evaluate the added masses and their derivatives with respect to the separation distance between the cylinders in terms of the hydrodynamic singularities, the method of successive images, initiated by Hicks, and the Taylor added-mass formula are applied, and analytic solutions in closed form are obtained thereafter.  The dynamic behaviour of a drifting body in close proximity of a fixed one is investigated by considering the limiting values of the fluid kinetic energy and the interaction forces on each body.  The reliability of the numerical approximation of added masses and their derivatives is also discussed in the present study.  The integral equations, in terms of surface source distributions and also discussed in the present study.  The integral equations, in terms of surface source distributions and their derivatives on both circles, are carefully modified for obtaining accurate numerical solutions.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/439826</guid>
    </item>
    <item>
      <title>THE ONSET AND DEVELOPMENT OF CIRCULAR-CYLINDER VORTEX WAKES IN UNIFORMLY ACCELERATING FLOWS</title>
      <link>https://trid.trb.org/View/439839</link>
      <description><![CDATA[The influence of uniform flow acceleration on the stability and the characteristics of circular-cylinder wakes over a Reynolds-number range, 20<R<330, was investigated.  Experiments were preformed to examine the temporal evolution of the wake before, during, and after the onset of the wake instability.  We have demonstrated in several ways that the wake is stabilised by flow acceleration:  (i) the onset of the wake instability occurs at larger Reynolds numbers than in the steady flow case, (ii) the closed wake develops to states that would be unstable in a steady flow, and (iii) once vortex shedding does occur there is a reduction in instantaneous Strouhal number.  We have also examined the temporal growth rate of the wake instability and find that it is directly proportional to the applied flow acceleration.  Physical mechanisms are proposed to describe the experimental observations.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/439839</guid>
    </item>
    <item>
      <title>THE EVALUATION OF STEADY FLUID FORCES ON SINGLE AND MULTIPLE BODIES IN LOW SPEED FLOWS USING VISCOUS BOUNDARY ELEMENTS</title>
      <link>https://trid.trb.org/View/439999</link>
      <description><![CDATA[Based on a viscous boundary element method, computations are presented of the steady flow or moving in a stationary, unbounded viscous fluid.  The developed theoretical approach is analogous to a potential flow singularity distribution panel method with singularity replaced by a fundamental solution derived from a modified Oseen equation developed through an integral equation formulation.  Analytical expressions are given for the fundamental solution (or oseenlet) appropriate to two- and three-dimensional problems and these contain both viscous and potential contributions.  To solve the non-linear integral equations requires a distribution of viscous panels over the wetted surface of the body and into the fluid domain, although the simplified linearised Oseen model needs only a body surface distribution.  The sensitivity of the solutions to idealisation, numerical truncation, etc. are discussed and predictions are compared with experimental data, over a wide range of Reynolds number.  The versatility of the method is demonstrated by evaluating the fluid-structure interactions between two unconnected cylinders fixed in a fluid flow.  However, the approach can be extended to problems involving arbitrary shaped bodies, e.g. a cluster of cylinders, a group of buildings, a hull and appendages, etc. with no further theoretical modifications, but an increased computational effort.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/439999</guid>
    </item>
    <item>
      <title>NUMERICAL STUDY OF AN OSCILLATING CYLINDER IN UNIFORM FLOW AND IN THE WAKE OF AN UPSTREAM CYLINDER</title>
      <link>https://trid.trb.org/View/440732</link>
      <description><![CDATA[Direct numerical simulation is carried out to study the response of an oscillating cylinder in uniform flow and in the wake of an upstream cylinder.  It is found that the response of the cylinder wake is either a periodic (lock-in) or a quasi-periodic (non-lock-in) state.  In the non-lock-in state, the vortex shedding frequency equals the forcing frequency.  In the non-lock-in state, the shedding frequency shows a smooth variation with the driving frequency.  For a cylinder oscillating in uniform flow, a lock-in diagram of different forcing amplitude is computed.  However, no clear chaotic behaviour is detected near the lock-in boundary.  For a cylinder oscillating in uniform flow, a lock-in diagram of different forcing amplitude is computed.  However, no clear chaotic behaviour is detected near the lock-in boundary.  For a cylinder oscillating in the wake of an upstream cylinder, the response state is strongly influenced by the distance between the two cylinders.  By changing cylinder spacing, two different flow regimes are identified.  In the 'vortex formation regime', found at large spacings, the vortex street develops behind both the upstream and downstream cylinders.  The strength of the naturally produced oscillation upstream of the second cylinder becomes important compared to the forced oscillation and dominates the flow, leading to a very small or even indistinguishable zone of synchronisation. However, in the 'vortex suppression regime', observed at small spacings, the oncoming flow to the downstream cylinder becomes do weak that it hardly affects its vortex wake, and therefore a large zone of synchronisation is obtained.  The numerical results are in good agreement with available experimental data.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/440732</guid>
    </item>
    <item>
      <title>A METHOD TO MEASURE PLANE FLOW VELOCITY BY PROCESSING VISUALISED INTENSITY DISTRIBUTION PROFILES OF STREAKLINES</title>
      <link>https://trid.trb.org/View/440878</link>
      <description><![CDATA[A hybrid method is under development to measure 3-dimensional velocity fields where the image processing of visualised flow and numerical computations are used.  The 3-dimensional velocity is computed from several scanned plane flows which have been obtained by flow visualisation and image processing.  It is necessary to analyse the plane flow fields as accurately as possible, for they are used as boundary conditions is computations for the 3-dimensional reproduction.  This paper proposes a new method to determine the plane flow velocity accurately.  The method is to analyse the intensity distribution profiles of visualised streaklines rather than the discrete images of tracers.  The velocity is determined from the movement of the profiles at three successive times.  The zero crossing points are invoked to characterise the profiles whose identification is much easier than the tracer method because of its 1-dimensional identification along the streakline.  The use of the distribution of the intensity rather than the binary data makes the results accurate where the results do not depend on the slice level.  Because the intensity distribution profile carries much information than discrete binary data, amendment for higher accuracy can be done by making use of the correlation function and so on.  The method is applied to analyse the uniform flow and plane flow around the stern of Wigley model.  Although several points are still left to be improved for higher accuracy, the present method provides much better plane flows than those obtained by the particle-trace method.  It is expected to be used for the computation of 3-dimensional flow reproduction.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/440878</guid>
    </item>
  </channel>
</rss>