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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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>Assessment of experimental, computational, and combined EFD/CFD methods for ship performance prediction</title>
      <link>https://trid.trb.org/View/2389038</link>
      <description><![CDATA[This thesis addresses the need for a comprehensive assessment of Experimental Fluid Dynamics (EFD), Computational Fluid Dynamics (CFD), and their combination to enhance the accuracy of performance predictions. Moreover, it explores the potential of combined EFD/CFD methods in improving power predictions by either replacing or complementing certain aspects of the existing methodology, while also introducing novel methods. The investigation identifies the Prohaska method as a prominent source of uncertainty in the ITTC-78 method. As an alternative, the CFD-based form factor method is meticulously examined, employing various codes and numerical approaches. The findings robustly establish the applicability and accuracy of the CFD-based form factor method, even when subjected to diverse numerical approaches and computational grids. Furthermore, best practice guidelines are derived for double-body RANS computations, ensuring compatibility with experimental form factors. Another debated issue within the ITTC-78 method is the very concept of form factor. This study conclusively affirms the Reynolds number dependence in form factors when the ITTC-57 line is employed. However, the numerical friction lines derived in this research, effectively eliminates these scale effects. Additionally, this study addresses conditions with flow separation, which renders the conventional form factor approach inadequate. A two form factor method (2−k method) is proposed to address instances of separated flow, complemented by an empirical correction formula for vessels with deep transom submergence and wetted transom flow. Furthermore, this thesis delves into the exploration of direct full-scale CFD computations for ship performance prediction. Extensive validation studies, encompassing numerous test cases and sea trials, are conducted to compare the accuracy of full-scale CFD computations with EFD based, and combined EFD/CFD methods. This thesis quantifies, for the first time in the literature, the difference in accuracy between fully computational and extrapolation-based methods using a large number of test cases and sea trials.]]></description>
      <pubDate>Mon, 10 Jun 2024 14:05:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2389038</guid>
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    <item>
      <title>Characterising turbulent ship wakes from an environmental impact perspective</title>
      <link>https://trid.trb.org/View/2389003</link>
      <description><![CDATA[The world's oceans, especially coastal areas, are intensively trafficked by ships. All these ships exert pressure on the marine environment, through emission to the atmosphere, discharges of pollutants to the water, and physical disturbance through energy input. Of these impacts, energy pollution from shipping has received the least attention. Especially the impact of ship-induced turbulence in the wake, which is induced by the hull friction and propeller, and remains for up to 15 minutes. The turbulent wake can impact the spread of contaminants, affect air-sea gas exchange, physically disturb plankton, and potentially impact local biogeochemistry through increased entrainment and vertical mixing. To assess these impacts, an understanding of the turbulent wake development and interaction with surface ocean stratification, is essential. However, characterisation of the turbulent wake development in time and space, especially in stratified conditions, is challenging and requires an interdisciplinary approach.  The aim of this thesis is to advance the understanding of turbulent wake development from an environmental impact perspective. The intensity and spatiotemporal extent of the turbulent wake, and its impact, have been investigated through a combination of in situ and ex situ observations, and Computational Fluid Dynamic (CFD) modelling of ships in full-scale. The unique dataset of several hundred in situ turbulent wake observations, showed large variation in spatiotemporal extent and intensity. Wake depths can reach down to 30 m, and the turbulent intensities in the near wake are 1–3 orders of magnitude higher than generally observed in the upper ocean surface layer. In addition, during stratified conditions ship-induced turbulence entrain water from below the pycnocline, with implications for local nutrient input and primary production in the ocean surface layer. In addition, ship-passages were observed to frequently trigger large methane emissions in an estuarine shipping lane.]]></description>
      <pubDate>Mon, 10 Jun 2024 14:05:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2389003</guid>
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    <item>
      <title>BeFo 440 - Injektering av bergsprickor under höga hydrauliska gradienter</title>
      <link>https://trid.trb.org/View/2269727</link>
      <description><![CDATA[Grouting of rock joints with considerable hydraulic gradient, i.e. flowing water, is a challenging issue in many rock engineering projects. Typical situations include post-excavation grouting and remedial grouting of dam foundations. There is still a need for basic research regarding the behaviour of the fresh grout in flowing water. Not until we understand this complex hydromechanics will it be possible to develop reliable design methodologies that can predict the decrease in hydraulic conductivity of the grouted rock mass. We propose an experimental research project to investigate 1) the erosion of fresh grout during grouting in flowing water, and 2) the likely favourable effect of relief wells that reduces the hydraulic gradient. In addition, we plan to develop a design methodology for remedial grouting of dam foundations, and a case study related to the subject will be made. The findings will be relevant also for post-excavation grouting in tunnels with similar hydraulic environments. The project results can therefore be highly useful in future application studies for post-excavation grouting. The project is part of a PhD project at KTH.]]></description>
      <pubDate>Mon, 16 Oct 2023 09:26:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2269727</guid>
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    <item>
      <title>Guide to road design part 5B: drainage: open channels, culverts and floodway crossings</title>
      <link>https://trid.trb.org/View/2134817</link>
      <description><![CDATA[Guide to Road Design Part 5B: Drainage – Open Channels, Culverts and Floodway Crossings contains guidance on the design of open channels, culverts and floodway crossings to support the operation and management of the road network. This Guide needs to be used in conjunction with the other two Parts of the Guide to Road Design that relate to drainage design:  Part 5: Drainage – General and Hydrology Considerations and Part 5A: Drainage – Road Surface, Network, Basins and Subsurface. This Guide provides guidance on the fundamentals of open channel, culvert and floodway crossing flows, and includes methods to undertake the design of these drainage facilities.]]></description>
      <pubDate>Mon, 06 Mar 2023 16:22:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2134817</guid>
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    <item>
      <title>Untersuchungen zur Lüftung von Straßentunneln anhand eines generischen Modells</title>
      <link>https://trid.trb.org/View/1872930</link>
      <description><![CDATA[Die Untersuchung soll die Aussagekraft des Modelltunnels der BASt im Maßstab 1:18  als experimentelles Modell und des begleitend zu Untersuchungen am Modelltunnel entwickelten numerischen Modells erweitern und die modellhafte Bearbeitung konkreter Fragestellungen zur Lüftung von Straßentunneln ermöglichen. Ein Schwerpunkt der Untersuchung ist die Durchführung realmaßstäblicher Strömungsmessungen in einem Tunnel zur Vervollständigung der Validierung des experimentellen und des numerischen Modells. Zur engeren Verzahnung der beiden Modelle (generisches Modell) wird die Frage adressiert, inwieweit strömungsmechanische Untersuchungen räumlich abgegrenzt durchgeführt, aber dennoch mit hinreichender Belastbarkeit auf den gesamten Tunnel übertragen werden können. Hierdurch wird eine Vereinfachung der Bearbeitung komplexer Situationen ebenso erwartet wie eine Erweiterung der Entscheidungsgrundlage für planerische Fragestellungen, gestützt auf Parameterstudien mittels des numerischen Modells. (A) ABSTRACT IN ENGLISH: The investigation is intended to extend the informative value of the BASt model tunnel on a scale of 1:18 as an experimental model and the numerical model developed in parallel to investigations on the model tunnel, and to enable the model-based processing of specific questions on the ventilation of road tunnels. A main focus of the investigation is the execution of real scale measurements in a tunnel to complete the validation of the experimental and the numerical model. For a closer integration of the two models as a generic model the question is addressed to what extent fluid mechanical investigations can be carried out in a spatially delimited manner, but still be related to the entire tunnel with sufficient transferability. This is expected to simplify the handling of complex situations as well as to extend the decision basis for planning issues, based on parameter studies using the numerical model. (A)]]></description>
      <pubDate>Wed, 27 Oct 2021 06:03:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1872930</guid>
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    <item>
      <title>Accounting Thermal Exchanges in Coanda Effect</title>
      <link>https://trid.trb.org/View/1701137</link>
      <description><![CDATA[An exhaustive model of Coandã effect has not been defined, and fundamental questions are still open. One of them is the influence of convective heat exchange on Coandã adhesion. This paper presents an even preliminary numerical study of this problem. It analyses the behaviour of a fluid stream on a convex surface in the presence of a temperature gradient between the fluid and the convex surface. It approaches the problem by a set of CFD simulations, analyses previous hypotheses, which are based on Prandtl number, and evidences the need for a model that account Reynolds number. The performed simulations are still not sufficient for an exhaustive comprehension of Coandã effect in the presence of heat exchange phenomena. It allows producing some consideration that may help future scientific work in toward a better comprehension of these phenomena. In particular, it verifies the importance of Reynolds number, because it is intrinsic in the adopted model, with good accordance with CFD data. In conclusion, this paper is still far from a complete model of the phenomena that govern the Coandã adhesion in the presence of convective heat exchange. Otherwise, it presents a preliminary starting point toward further and more detailed analyses.       ]]></description>
      <pubDate>Mon, 22 Jun 2020 17:53:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1701137</guid>
    </item>
    <item>
      <title>Water in roads : flow paths and pollutant spread</title>
      <link>https://trid.trb.org/View/1652337</link>
      <description><![CDATA[For better road construction and maintenance while minimising damage to the environment and groundwater, it is essential to monitor and model hydrological impacts on roads and consider pollution of groundwater. Water content in unbound material in road layers changes continuously and water flow usually occurs along pathways that are the main corridors for pollutant spread to groundwater. Good awareness of hydrological conditions and of water and solute transport in road layers down to the groundwater can be helpful in minimising environmental impacts during construction and operation. Today, road planning is usually carried out without specifically considering hydrological criteria. To improve understanding of the links between water in roads and groundwater, this thesis developed investigation methods and used numerical simulations for estimating seasonal variations, flow pathways and pollutant spread. Seasonal changes in road water content in an operational road, tracer tests pathways from the road shoulder and percolation down to groundwater were monitored non-destructively using electrical resistivity tomography (ERT). Chloride concentration changes were estimated based on ERT data inversion. New monitoring methodology was assessed and data analysis was performed on ERT data from different road zones and layers, which were analysed statistically and correlated to precipitation, temperature and ground moisture content. Data were collected at a unique road test station on a motorway north-west of Stockholm and in tracer experiments on typical roads in southern and central Sweden. Two-dimensional (2D) models of heat and moisture changes were prepared for a road section, considering vapour pressure and frozen water content changes using partial differential equations (PDE). Model parameters were optimised based on soil moisture and temperature data from the E18 road test station. A PDE model was used for calculating liquid water and ice content changes in different scenarios based on geometry and design changes. Both pathways and travel times were traced by 2D and pseudo 3D inverse modelling of the ERT measurements.]]></description>
      <pubDate>Tue, 17 Sep 2019 10:33:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1652337</guid>
    </item>
    <item>
      <title>A comparison of the effect of pier shape on flood loading on bridges</title>
      <link>https://trid.trb.org/View/1468059</link>
      <description><![CDATA[The resistance to flood and debris loading are critical parameters affecting design of bridges under flood loading. For instance, bridges which are under extreme flood could partially or completely immerse in the water, resulting in very notable hydrodynamic loads on the decks and piers. Typical design process would convert the flood loading in to a static force, which cannot reflect the full effect of flood and the debris loading on different shaped piers. Therefore, it is important to investigate the effect of flood loading on piers of different shapes. This work simulates the flooding effect on the piers using a finite volume method in ANSYS Fluent. The pier is modelled as a column with a square cross section or a circular cross section. The pier has been simplified as a nonslip boundary for fluid domain as well as bed and sidewall. It is assumed that the domain size is 5x7x3.5 m3 and the pier is a 0.355 m2 in dimension. A numerical model has been developed to examine the influences of velocity variation in the range of 0.5m/s to 10m/s on the hydrodynamic pressure exerted on the pier. The developed model is employed to explore the behaviour of pressure exerted by food flow on a pier. Comparison between the equivalent hydro-static load suggested by AS 5100 and the numerical analysis has been presented. Outcomes demonstrate that the AS 5100 method is appropriate for evaluating the pressure on square piers whereas the method is inadequate for predicting the pressure on circular piers.]]></description>
      <pubDate>Wed, 24 May 2017 14:08:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468059</guid>
    </item>
    <item>
      <title>Simulation of secondary and separated flow in a diffusing S-duct using four different turbulence models</title>
      <link>https://trid.trb.org/View/1320325</link>
      <description><![CDATA[The focus of this article is on the numerical simulation of compressible flow in a diffusing S-duct inlet; this flow is characterized by secondary flow as well as regions of boundary layer separation. The S-duct geometry produces streamline curvature and an adverse pressure gradient resulting in these flow characteristics. The geometry used in this investigation is based on a NASA Glenn Research Center experimental diffusing S-duct that was studied in the early 1990s. The computational fluid dynamics flow solver ANSYS-FLUENT is employed in the investigation of compressible flow through the S-duct. A second-order accurate, steady, density-based solver is employed in a finite-volume framework. The three-dimensional Reynolds-Averaged Navier-Stokes equations are solved on a structured mesh with a number of turbulence models, namely the Spalart–Allmaras (SA), k-ε, k-ω SST, and Transition SST models, and the results are compared with the experimental data. The computed results capture the flow field and pressure recovery with acceptable accuracy when compared with the experimental data. The turbulence model giving the best results is identified.]]></description>
      <pubDate>Wed, 27 Aug 2014 10:54:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1320325</guid>
    </item>
    <item>
      <title>Fracture processes and in-situ fracture observations in Gipskeuper</title>
      <link>https://trid.trb.org/View/1290612</link>
      <description><![CDATA[Several tunnels constructed in sulfate-rich clay rocks revealed severe and costly problems associated with floor heave as a consequence of gypsum precipitation. Previous studies have shown that gypsum precipitation often takes place within pre-existing natural structures or fissures which were created by hoop-stresses and opened as a consequence of radial stress relief. Brittle fracture processes cause a damage zone around an underground excavation in sulfate-rich clay rock when the stress exceeds the crack initiation threshold. Microcracks in the damage zone are seen as a preconditioning factor for gypsum precipitation when sulfate-rich fluids penetrate these fissures and become supersaturated. However, brittle failure pro-cesses in sulfate-rich clay rocks and the stress magnitudes required to initiate microcracks were previously not studied in detail, and the hypothesis of brittle fracturing as a major cause for swelling has not been conclusively proven. It was also not studied in detail newly formed fractures actually exist in the vicinity of tunnels in this rock type, and if these fracture may be related to stress fracturing or unloading or propagation of pre-existing discontinuities. Furthermore, the influence of newly formed fractures on fluid flow and gypsum precipitation was not demonstrated. ln this study we test these hypotheses with data from new boreholes and cores drilled into the Gipskeuper formation intersected by the Belchen tunnel in the Swiss Jura Mountains. The investigation primarily focuses on the stress magnitude at which microcracks initiate in Anhydrite-Clay rocks, on factors such as heterogeneities that affect the fracturing processes and strength, and on micro-structural observations below the invert of the Belchen drainage tunnel. This investigation provides insights into the fracture formation mechanisms and its influence on preferential pathways for fluid flow and gypsum precipitation.]]></description>
      <pubDate>Fri, 31 Jan 2014 14:14:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1290612</guid>
    </item>
    <item>
      <title>Guide to road design part 5B: drainage: open channels, culverts and floodways</title>
      <link>https://trid.trb.org/View/1252607</link>
      <description><![CDATA[Guide to Road Design Part 5B: Drainage &ndash; Open Channels, Culverts and Floodways contains guidance on the design of open channels, culverts and floodways to support the operation and management of the road network.  This Guide needs to be used in conjunction with the other two Parts of the Guide to Road Design that relate to drainage design: 1. Part 5: Drainage - General and Hydrology Considerations; 2. Part 5A: Drainage - Road Surface, Network, Basins and Subsurface.  This Guide provides guidance on the fundamentals of open channel, culvert and floodway flows, and includes methods to undertake the design of these drainage facilities.]]></description>
      <pubDate>Thu, 13 Jun 2013 12:25:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1252607</guid>
    </item>
    <item>
      <title>On the dynamics of porous media: application to road and railway structures</title>
      <link>https://trid.trb.org/View/1215529</link>
      <description><![CDATA[Load-bearing road and railway structures normally consist of layers of particulate porous materials, often with bitumen-based binders. The layered system is subjected to dynamic loading from traffic, which inevitably causes material deterioration that enhances permanent surface deformation. For example, internal erosion of fines from the solid skeleton is brought about by high seepage rates in the open pore system. The interplay between deformation, pore-water flow and material degradation is a highly complex problem that poses significant challenges from both the modeling and computational viewpoints. The thesis is, therefore, concerned also with means of reducing the computational cost without jeopardizing the predictive capability. The so-called Porous Media Theory (a mixture theory with phase volume fractions) is adopted as the modeling paradigm. In order to model the coupling between deformation and pore-water flow in the presence of internal erosion, a triphasic erosion system is considered in terms of the solid skeleton and an ideal mixture of pore-water and eroded fines (the abrasive phase). Small strain kinematics is assumed, and the pertinent model is obtained from consistent linearization of finite strain kinematics. Linear elastic response is assumed in the absence of erosion (for fixed porosity); however, strong nonlinearity in stiffness and permeability arise due to the finite change of porosity from erosion. The developed simulation tool is used to analyze a simplified road structure subjected to dynamic loading. As part of the effort to reduce the model complexity and computational cost, different simplifying approximations for the relative fluid acceleration are assessed. From the numerical examples, it is concluded that the convective part of the relative fluid acceleration may be neglected without significant loss of accuracy; however, simply using the "added mass" approximation is normally unacceptable. A novel space-variational format with reduced number of global fields was developed based on the time-discretized balance equations. For the adopted triphasic system, three global fields (displacement, pore-pressure and abrasive volume fraction) and two local fields (seepage velocity and total porosity) constitute the coupled problem. The local fields can be eliminated similarly to internal variables in constitutive models. A comparison with the "classical" format carried out for a biphasic model (without erosion) showed that the novel format competes well in terms of convergence behavior.]]></description>
      <pubDate>Mon, 01 Oct 2012 13:15:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1215529</guid>
    </item>
    <item>
      <title>RTA study on the use of self-compacting concrete</title>
      <link>https://trid.trb.org/View/1138205</link>
      <description><![CDATA[Self-compacting concrete (also known as Super-workable concrete in Australia and Self-consolidating concrete in North America) is defined in EN 206 Part 9: Additional Rules for Selfcompacting Concrete (SCC) as concrete that is able to flow and compact under its own weight, completely fill the formwork with its reinforcement, ducts, box outs etc, whilst maintaining homogeneity. A study on self-compacting concrete was conducted by RTA Bridge Engineering for the possible use of SCC in certain reinforced and prestressed concrete bridge elements where mechanical compaction is hindered by OHS requirements and often times not practically feasible to assure a homogeneous concrete end product. Self-compacting concrete is considered as an improvement on the current applications of high or very high slump flowable concrete. This paper will discuss the conducted study that includes laboratory mix design trials, full scale field trials and the project verification trials. The study resulted in the preparation of draft clauses for the inclusion of SCC in the next major amendment of the RTA QA Specifications B80 - Concrete Work for Bridges (RTA B80).]]></description>
      <pubDate>Thu, 03 May 2012 10:44:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1138205</guid>
    </item>
    <item>
      <title>Wavelet analysis of turbulent velocity fields in a spark ignition engine</title>
      <link>https://trid.trb.org/View/1100286</link>
      <description><![CDATA[The issue of decomposing in-cylinder flow into mean and turbulence velocities remains unresolved. Spark Ignition (SI) engine flows are inherently non-stationary because of the piston and valve motions. In SI engine combustion chamber, turbulence is superimposed on unsteady organised motion of a mean flow. These turbulent flows have been studied by time or ensemble averaging methods and low-pass, high-pass filter methods. In this study, wavelet transform has been applied to experimentally measured turbulent velocity field in an SI engine to extract information about coherent structures. The radial and circumferential turbulent velocity fields are measured using hot wire anemometer under motoring conditions at various engine configurations. (A)]]></description>
      <pubDate>Fri, 15 Apr 2011 16:19:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1100286</guid>
    </item>
    <item>
      <title>Sizing of riprap for spill-through abutments</title>
      <link>https://trid.trb.org/View/1100167</link>
      <description><![CDATA[An experimental investigation of riprap stability at spill-through abutments was carried out in two similar horizontal-bed flumes, avoiding riprap failure modes other than shear failure and erosion failure. Tests were conducted for two common abutment side slopes, sub-critical flow regime, short to intermediate abutment lengths and high bed roughness. The aim of the experiments was to determine the size of stone riprap necessary to resist (a) shear failure in aprons placed at the base of spill-through abutments, and (b) erosion failure over their side slopes. Results are compared with predictions of stone riprap size given by expressions found in the literature. The predictor of Pagan-Ortiz is confirmed as being appropriate for shear failure at abutment aprons and can be adapted to account for erosion failure over abutment side slopes. Alternatively, two new mathematical expressions, written in terms of the (critical) approach flow intensity required to make the riprap stones move, are suggested]]></description>
      <pubDate>Fri, 15 Apr 2011 15:57:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1100167</guid>
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