<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>Nonplanar multi-modal vibrations of fluid-conveying risers under shear cross flows</title>
      <link>https://trid.trb.org/View/1604815</link>
      <description><![CDATA[Risers/pipes conveying fluid are a typical kind of slender structures commonly used in marine engineering. It is of great academic significance and application value for us to evaluate and understand the vibration characteristics and nonlinear responses of these risers under the combined action of internal and external fluid flows. In this paper, the nonplanar vibrations and multi-modal responses of pinned-pinned risers in shear cross flow are numerically studied. With this objective in mind, the van der Pol wake oscillators are used to simulate the dynamical behavior of the vortex shedding in the wake. Two nonlinear equations of motion of the riser are proposed to govern the lateral responses of the riser structure. The nonplanar nonlinear equations for the riser and wake are then discretized by employing Galerkin's method and solved by using a fourth-order Runge–Kutta integration algorithm. Theoretical results show that the coupled frequencies for cross-flow (CF) and in-line (IL) motions and the corresponding coupled damping ratio could be influenced by the external and/or internal fluid velocities. Based on extensive calculations, the dynamical behavior of the riser with various internal and external flow velocities are presented in the form of bifurcation diagrams, time traces, phase portraits, oscillation trajectories and response spectrum curves. It is shown that some interesting dynamical phenomena, such as ‘lock-in’ state, ‘figure-of-eight’ trajectory and quasi-periodic oscillation, could occur in such a fluid-structure interaction system. The authors' results also demonstrate that the shear parameter can significantly affect the dynamic responses of the riser. When the shear parameter of the cross flow is large, multi-modal quasi-periodic responses of the riser can be excited, showing some new features undetected in the system of fluid-conveying risers in uniform cross flow.]]></description>
      <pubDate>Mon, 29 Jul 2019 11:03:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1604815</guid>
    </item>
    <item>
      <title>CFD analysis of fluid flow inside a pentroof combustion chamber with different piston shapes</title>
      <link>https://trid.trb.org/View/1464153</link>
      <description><![CDATA[In the present work a study of in-cylinder flow for spark ignition (SI) engine is carried out, for pentroof head piston geometry with four different configurations of the piston crown. The flow pattern is investigated using commercial software package Fluent 6.3 during intake and compression stroke at different engine speeds. The parameters investigated are turbulent kinetic energy (TKE) and tumble ratio. The nature of computed velocity and TKE contours for flat piston combustion chamber is found to be in good agreement with experimental results (Murali et al., 2010). Furthermore, it is found that piston shape significantly affects the velocity and TKE contours of SI engine during the compression stroke. The combustion chamber with trapezoidal piston shows more TKE and tumble ratio when compared to other pistons at 330 crank angle degree, i.e., near TDC during compression, where turbulence is most essential before ignition.]]></description>
      <pubDate>Thu, 25 May 2017 13:56:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1464153</guid>
    </item>
    <item>
      <title>3D Modeling of Piping Mechanism Using Distinct Element Method</title>
      <link>https://trid.trb.org/View/934519</link>
      <description><![CDATA[A 3D coupled continuum-discrete hydromechanical model was utilized to simulate the pore fluid flow and solid particle transport during piping in a micro scale. The fluid phase was implemented using the "fixed coarse-grid" fluid scheme based on Navier-Stokes equations and the solid phase which consists of an assemblage of discontinuous particles can be modeled effectively using DEM. Numerical simulations were conducted to investigate the mechanisms of macro-meso response of fluid and grains during piping in the presence of increase hydraulic gradient. The fluid velocity, loss fraction of eroded particles, pathway of moving particles, and etc are traced and recorded. The outcome of these simulations was consistent with experimental observations and revealed valuable information on the micro-mechanical characteristics of piping in sandy soil.]]></description>
      <pubDate>Fri, 24 Sep 2010 07:50:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/934519</guid>
    </item>
    <item>
      <title>Comparative Testing of Slurry Monitors</title>
      <link>https://trid.trb.org/View/871197</link>
      <description><![CDATA[The U.S. Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes stored in underground tanks. These wastes must be retrieved, transferred to treatment facilities, and processed for disposal. Before removal from the storage tanks, the sludge and liquid wastes will typically be combined to create a mixture of suspended solids, generally referred to as a slurry; the slurry is then pumped from the tank to the treatment facilities by pipelines. Since the wastes are radioactive, it is critically important that the slurries are transported safely and successfully. The consequences of pipeline plugging are unacceptable from the perspectives of schedule, cost, and safety. The baseline method of ensuring that the transport properties of the slurries are correct is to sample the slurry in the tank and analyze the sample in the laboratory. This method has some problems. First, there is a delay between the time that the sample is taken and the time that the analytical results are reported. For some types of analysis, this delay could be from 24 to 48 hours. Second, although the tank is being mixed to keep tile solids in suspension during this period, there is no way to determine whether the contents of the tank are homogenous unless multiple samples are collected at various depths and locations. Therefore, an on-line system that monitors slurry transport properties in real time is needed to evaluate the slurry prior to and during transfer.]]></description>
      <pubDate>Mon, 29 Sep 2008 11:47:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/871197</guid>
    </item>
    <item>
      <title>Dynamic Effects on Moisture Transport in Asphalt Concrete</title>
      <link>https://trid.trb.org/View/811661</link>
      <description><![CDATA[Permeability of an asphalt pavement is one of the most important parameters that have a direct influence on its design life. It is an intrinsic property that relates the average fluid velocity to a constant pressure gradient; however, the external pressures on a saturated pavement pore structure are often dynamic due to the repeated tire loading in the field. A dynamic permeability constant, therefore, is a more realistic representation of the response of a pavement pore structure to external stresses. In order to investigate the unsteady (dynamic) fluid flow in asphalt pavements, a three-dimensional fluid flow model was developed using the lattice Boltzmann method. The model was validated using the well-known closed form solution of oscillating flow through a circular tube. Simulations were carried out to calculate the permeabilities of different asphalt specimens exposed to pulsatile pressures as well as the pore pressures and shear stresses at the solid–water interfaces. The results indicated that the dynamic permeability of an asphalt pore structure collapses on a single curve for a given frequency, confirming a universal behavior. Dynamic effects were generally limited to near the surface of the specimens analyzed, and the pore pressures and velocities varied nonlinearly along the depth due to the heterogeneous nature of the asphalt specimens. The results are encouraging yet should be considered preliminary as they are based on stone matrix asphalt specimens and one type of pulsatile load analyzed.]]></description>
      <pubDate>Fri, 20 Jul 2007 09:53:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/811661</guid>
    </item>
    <item>
      <title>Characteristics of Horseshoe Vortex in Developing Scour Holes at Piers</title>
      <link>https://trid.trb.org/View/806521</link>
      <description><![CDATA[The outcome of an experimental study on the turbulent horseshoe vortex flow within the developing (intermediate stages and equilibrium) scour holes at cylindrical piers measured by an acoustic Doppler velocimeter (ADV) is presented. Since the main aim was to analyze evolution of the turbulent flow characteristics of a horseshoe vortex within a developing scour hole, the flow zone downstream of the pier was beyond the scope of the investigation. Experiments were carried out for the approaching flow having undisturbed flow depth (=0.25 m) greater than twice the pier diameter and the depth-averaged approaching flow velocity (=0.357 m/s) about 95% of the critical velocity of the uniform bed sand that had a median diameter of 0.81 mm. The flow measurements by the ADV were taken within the intermediate (with depths of 0.25, 0.5, 0.75 times the equilibrium scour depth) and equilibrium scour holes (frozen by spraying glue) at a circular pier of diameter 0.12 m. In order to have a comparative study, ADV measurements within an equilibrium scour hole at a square pier (side facing the approaching flow) of sides equaling the diameter of the circular pier were also taken. The contours of the time-averaged velocities, turbulence intensities, and Reynolds stresses at different azimuthal planes (0, 45, 90°) are presented. Vector plots of the flow field at azimuthal planes reveal evolution of the characteristics of the horseshoe vortex flow associated with a downflow from intermediate stages to equilibrium condition of scour holes. Bed-shear stresses are determined from Reynolds stress distributions. Flow characteristics of the horseshoe vortex are discussed from the point of view of similarity with velocity and turbulence characteristic scales. An imperative observation is that flow/turbulence intensities in the horseshoe vortex flow in a developing scour hole are reasonably similar.]]></description>
      <pubDate>Wed, 25 Apr 2007 13:46:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/806521</guid>
    </item>
    <item>
      <title>SuDS in the city</title>
      <link>https://trid.trb.org/View/790873</link>
      <description><![CDATA[This article describes the design of a sustainable drainage system (SuDS) for a new commercial development near the city of Liverpool, north west England. The site is crossed by two watercourses and is near to sewage pipes and treatment works. Drainage had to be shallow, to meet highway safety standards and to attenuate runoff to Environment Agency limits. SuDS components used were swales for highway drainage and detention ponds for development runoff. Outflow from ponds and swales are conveyed into one of the watercourses: the opportunity was taken to improve its quality and the wildlife habitats it offers. The components of the system were individually designed to work together. Stage one of the design process involved the overall site drainage strategy, including the flatter gradients of a SuDS which could cross the existing sewer pipe. Stage two identified individual system components and their connectivity; and flow control pipes were located. Stage three included the construction of a hydraulic model in computer simulation, to assess flow volume and velocity in various rainfall situations. It is hoped that the highway authority will adopt the drainage swales.]]></description>
      <pubDate>Tue, 03 Apr 2007 14:41:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/790873</guid>
    </item>
    <item>
      <title>Estimating Directional Permeability of Hot-Mix Asphalt by Numerical Simulation of Microscale Water Flow</title>
      <link>https://trid.trb.org/View/801645</link>
      <description><![CDATA[Permeability of hot-mix asphalt (HMA) is an important property that influences asphalt’s resistance to moisture damage. All current methods used by pavement engineers rely on measuring vertical permeability. Recently, however, it has been shown that horizontal permeability can be much higher than the vertical because of the anisotropic and heterogeneous nature of air void distribution. Laboratory and field measurements of horizontal permeability require sophisticated equipment and detailed procedures that limit the ability to measure this property routinely. This study developed a procedure for estimating the horizontal permeability of asphalt mixes. The procedure requires simple laboratory measurements of vertical permeability and porosity (percent air voids) of sublayers in a specimen. The development of this simple method was supported by numerical simulations of microscale fluid flow in a wide range of HMA mixtures. The simulations helped in understanding the factors that control vertical and horizontal permeabilities. The developed equation and the numerical simulations confirmed that the horizontal permeability is several times higher than the vertical permeability.]]></description>
      <pubDate>Wed, 21 Mar 2007 12:46:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/801645</guid>
    </item>
    <item>
      <title>Field Methods for Monitoring Solute Transport</title>
      <link>https://trid.trb.org/View/790212</link>
      <description><![CDATA[This chapter presents commonly applied direct methods for in situ solute extraction.  The chapter also provides a comprehensive overview of common and advanced indirect methods and sensors for monitoring solute transport under filed conditions and finally the chapter discusses their applications based on two case studies.  At the end of the chapter a comparison of various methods and an outlook regarding future research opportunities is provided.]]></description>
      <pubDate>Fri, 29 Sep 2006 10:37:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/790212</guid>
    </item>
    <item>
      <title>Preferential Flow: Identification and Quantification</title>
      <link>https://trid.trb.org/View/790211</link>
      <description><![CDATA[Through both experimental and theoretical approaches, the speedy arrival of water and chemicals through preferential pathways has attracted the attention of researchers.  This chapter provides a review of some of the experimental and mathematical approached that have been used to quantify the flow of water and chemicals in soils displaying preferential transport.  The chapter also gives an overview of the experimental techniques such as staining, tension infiltrometer, and lysimeter for identification and quantification of preferential flow and soluble transport, as well as state-of-the-art mechanistic methods considering hydrodynamic principles.  Mechanistic-empirical and stochastic approaches are also discussed.  Finally, the chapter provides a review of the manipulated Darcian approaches and it provides a new three-domain concept for quantifying the infiltration rate for soils displaying differential flow.]]></description>
      <pubDate>Fri, 29 Sep 2006 10:37:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/790211</guid>
    </item>
    <item>
      <title>Coupled Heat-Deformation-Flow Analysis for Clayey Soil</title>
      <link>https://trid.trb.org/View/782713</link>
      <description><![CDATA[Thermal stress imposed on soil is coupled with the expulsion of pore fluid resulting in thermomechanical fluid flow. This paper describes a coupled flow-deformation model subjected to a constant temperature. Two-dimensional numerical modeling was performed based on the finite element method applied to thermoporoelasticity. The model evolves from application of the principles of irreversible thermodynamics. A heating experiment was designed to measure temperature and thermal deformation at predefined locations in a cylindrical clay disk. Results from the experiment are compared with the simulated results to validate the numerical scheme. Sensitivity analysis of the developed code reaffirmed that the coupling effects are most pronounced for high porosity and low permeability medium.]]></description>
      <pubDate>Mon, 03 Jul 2006 08:11:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/782713</guid>
    </item>
    <item>
      <title>SEEPAGE UNDER A RECTANGULAR DAM</title>
      <link>https://trid.trb.org/View/118353</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Sun, 15 Aug 2004 01:53:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/118353</guid>
    </item>
    <item>
      <title>A THEORY OF TRAFFIC FLOW FOR EVALUATION OF GEOMETRIC ASPECTS OF HIGHWAYS</title>
      <link>https://trid.trb.org/View/117061</link>
      <description><![CDATA[AN ANALYTIC APPROACH IS DEVELOPED WHEREBY THE VARIOUS ASPECTS OF A HIGHWAY (SUCH AS CURVES, GRADES, LANE WIDTH, TRAFFIC CONTROL DEVICES, TYPE AND CONDITION OF SURFACING) CAN BE EVALUATED QUANTITATIVELY UNDER VARYING TRAFFIC DENSITY AND WEATHER CONDITIONS PROVIDING A RATIONAL BASIS FOR GEOMETRIC DESIGN. IN THE PRESENT ANALYSIS IT IS POSTULATED THAT TRAFFIC REACTS TO A MOTIVATING PRESSURE POTENTIAL IN A PATTERN THAT DETERMINES THE BEHAVIOR OF ANY PARTICULAR VEHICLE TRAVERSING A GIVEN SECTION OF ROADWAY. THIS CONCEPT CAN BE EXPRESSED QUANTITATIVELY IN A MANNER ANALOGOUS TO THAT USED IN DESCRIBING ONE-DIMENSIONAL VISCOUS FLOW IN A COMPRESSIBLE FLUID. SOLUTION OF THE RESULTING DIFFERENTIAL EQUATION YIELDS A PARAMETER WHICH IS A NUMERICAL MEASURE OF THE SALIENT CHARACTERISTICS OF A ROAD. PROCEDURES ARE THEN PROPOSED TO DETERMINE THIS PARAMETER, USING MEASURABLE VEHICULAR VELOCITIES, WHICH ELIMINATE THE NEED FOR EVALUATING THE MOTIVATING PRESSURE POTENTIAL.]]></description>
      <pubDate>Fri, 13 Aug 2004 18:56:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/117061</guid>
    </item>
    <item>
      <title>DETERMINATION OF TRANSITION ZONES IN SETTLING BASINS</title>
      <link>https://trid.trb.org/View/98999</link>
      <description><![CDATA[A VISUAL METHOD FOR DETERMINING THE FLOW FIELD WHICH EXISTS IN A SETTLING BASIN WAS DEVELOPED. THE METHOD INVOLVES PHOTOGRAPHING THE PATH OF PARTICLES WHICH BEHAVED AS THE FLUID TO DETERMINE COORDINATE POSITIONS THAT COULD BE DETERMINED AS A FUNCTION OF TIME. THE DEVELOPED METHOD CAN QUALITATIVELY EVALUATE THE FLOW FIELDS AND OUTLETS FOR SETTLING BASINS. THE DISTANCE IN THE DIRECTION OF FLOW REQUIRED FOR THE INLET JET ACTION OVER A SHARP EDGED WEIR TO BECOME DISPERSED INCREASES AS THE HEIGHT OF THE WEIR DECREASES, AND THE EFFECT IS EXTENDED FURTHER DOWNSTREAM IF THE FLOW RATE IS INCREASED FOR A GIVEN WEIR HEIGHT. NAPPE CURVES OVER SHARP EDGED INLET WEIRS WERE OBTAINED FOR A RELATIVELY DEEP SETTLING BASIN MODEL AS A RESULT OF THE DEVELOPED FLOW VISUALIZATION METHOD.]]></description>
      <pubDate>Thu, 29 Jul 2004 18:19:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/98999</guid>
    </item>
    <item>
      <title>1992 COLUMBIA RIVER SALMON FLOW MEASURES OPTIONS ANALYSIS/EIS</title>
      <link>https://trid.trb.org/View/406083</link>
      <description><![CDATA[This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FSWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and one private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described.]]></description>
      <pubDate>Fri, 03 Oct 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/406083</guid>
    </item>
  </channel>
</rss>