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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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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>Testing Rig for Laboratory Research of Tyre Pressure Transducers</title>
      <link>https://trid.trb.org/View/2579375</link>
      <description><![CDATA[The study of inflation pressure for passenger car tyres represents a field of interest for automotive research, having major influence on tyre-road interaction, with respect to automotive dynamics and safety, vehicle comfort, rolling resistance, traction, braking and cornering. The investigation of inflation pressure is crucial in automotive testing, because essential information can be obtained concerning the behaviour of tyres in rolling conditions. The current paper focuses on experimental investigation of inflation pressure using measuring systems that can be mounted inside passenger car tyres. The aim of the paper is to perform the comparison of pressure transducers with measuring ranges adequate for study of inflation pressure but also with size and mass suitable to tyre mounting. For transducers validation, a newly designed testing rig has been developed to allow pressure adjustment and verification using digital and analog display manometers. Experiments have been performed for two small-size pressure transducers for determining the measuring range, sensitivity and offset. Conversion diagrams and linearity errors have been obtained experimentally for the two pressure transducers and very good repeatability has been ascertained. The sensitivity and offset provided by the transducers manufacturer were found to be different from real values obtained in laboratory tests, therefore the verification through experiments lead to update of these technical specifications. The experimental investigation of pressure transducers contributed substantially to the design of portable system for future application in tyre rolling conditions, but further research is required for development of pressure measuring system for road rolling tyres.]]></description>
      <pubDate>Mon, 13 Jul 2026 10:46:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2579375</guid>
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    <item>
      <title>Measurement of Rate of Multiple-Injection in CDI Diesel Engines</title>
      <link>https://trid.trb.org/View/1787232</link>
      <description><![CDATA[The injection rate meter based on W. Zeuch's method was improved to meet the recent requirement for precise measurement of the multiple injection rate and amount in CDI (Common rail Direct Injection) diesel engines. A pressure sensor with a high sensitivity was added to measure the small pressure increase due to the pilot injection and after injection. At the same time a flow meter having a high accuracy was installed in the discharge pipe line to obtain a correction factor to the modulus of elasticity of volume. As a result it became possible to measure the multiple injection amount at an accuracy of ±0.2mm³/stroke in a range up to 40mm³/stroke.]]></description>
      <pubDate>Sat, 30 Nov 2024 15:27:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1787232</guid>
    </item>
    <item>
      <title>Loads on Structure and Waves in Ice (LS-WICE) Project, Part 1: Wave Attenuation and Dispersion in Broken Ice Fields</title>
      <link>https://trid.trb.org/View/1722646</link>
      <description><![CDATA[A multi-group investigation was conducted at Hamburgische Schiffbau-Versuchsanstalt GmbH (HSVA) from Oct. 24 to Nov. 11, 2016 under the Hydralab+ Transnational Access project: Loads on Structure and Waves in Ice (LS-WICE). There are three parts to this investigation: ice fracture under wave actions, wave attenuation/dispersion in broken ice covers, and ice-structure interaction under wave conditions. This paper focuses on the wave attenuation/dispersion part of the investigation. A level ice sheet was produced first. The physical and mechanical properties were measured in the Large Ice Model Basin (LIMB) before passing through a range of waves to obtain the attenuation/dispersion relation. Wave measurements were monitored with pressure transducers and ultrasound sensors. The test sequence began with a continuous ice sheet followed by broken ice sheet. The broken ice sheet was produced by cutting the continuous ice sheet into uniform size floes. A range of floe sizes and wave periods were tested. Results of the data obtained and their implications to wave propagation in the marginal ice zone populated with different broken ice floes will be presented.]]></description>
      <pubDate>Wed, 22 Jul 2020 15:52:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1722646</guid>
    </item>
    <item>
      <title>Development of a Mass-Based Automated Passenger Counter</title>
      <link>https://trid.trb.org/View/1687842</link>
      <description><![CDATA[Automatic passenger counters (APCs) provide passenger boarding and alighting information associated with time and location data.  The cost of current APC systems can be prohibitive for smaller fleets with small capital budgets,  and integration with existing bus controllers and agency databases is also challenging.  This IDEA project develops an inexpensive passenger counting system that allows simple integration with existing vehicle information systems to reduce cost. The system relates bus mass to passenger boarding and alighting using pressure transducers located in the air spring suspension system. A micro-controller installed on the bus conducted calculations at the stop event. A feed forward neural network and convolutional neural network algorithm were used to analyze the shape of the signal and predict boarding and alighting at each stop. Built using commercially available, open-source software and hardware, this new system is cost-effective, easy to setup and could be integrated with existing transit agency databases.  During the project, the system was integrated on four in-use transit buses around the Minneapolis-Saint Paul metropolitan area. The machine learning algorithms had 91% accuracy for a subset of the data used in training the algorithms. However, testing with the trained algorithms showed that the mass-based APC was 61% and 38% accurate in recording boarding and alighting events, respectively.  Although the algorithms had poor accuracy for alighting events, especially, the system was able to estimate the mass of the bus at each stop accurately. As the project progressed, new, vision-based APC systems were brought to the market by other manufacturers. Based on the testing data collected in this project, the developed APC could not compete with the accuracy obtained by these new systems.  In an extension of this IDEA project, the University of Minnesota team used instantaneous bus mass recorded by the developed system to estimate the effect of passenger loading on fuel economy and bus energy consumption. A simulation study was done using multiple days of second-by-second bus mass and speed with hybrid and conventional buses to show the effect of passenger loading on the fuel consumption of each technology. The results showed that fuel consumption in hybrid buses are less affected by passenger mass since the additional mass increases the available energy from regenerative braking.]]></description>
      <pubDate>Thu, 20 Feb 2020 10:10:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1687842</guid>
    </item>
    <item>
      <title>In Situ Injection Rate Measurement to Study Single and Split Injections in a Heavy-Duty Diesel Engine</title>
      <link>https://trid.trb.org/View/1653455</link>
      <description><![CDATA[The split injection strategy holds a potential for high pressure combustion engines. One advantage of such strategy is the capability to control the heat release rate, which also implies the use of multiple split-injections with relatively short dwell intervals. Most injection rate measurement techniques require installment of the injector on a dedicated test rig. However, these techniques fail to accurately reproduce real-engine operating conditions. Using the spray impingement method, this paper investigates the injection rate of a high flow-rate solenoid injector while being operated on the engine. The aim is to have an experimental configuration as similar as possible to the real engine in terms of the acoustics and the fuel temperature within the injection system. The assumption of spray force proportional to the spray momentum is used here to measure the injection rate. The spray momentum is measured while the injector is mounted on the Volvo D13 engine and connected to the in-series fuel rail and pump. A high-natural-frequency piezoelectric pressure transducer is mounted perpendicularly at 4 mm from one of the nozzle holes. The injector and sensor are contained within a specially designed collector for the injected fuel, which is maintained at atmospheric pressure and temperature. Experiments with single injection are conducted varying the Duration of Injection (DOI) from 400 up to 2000 µs. The tests with split double-injections are conducted with fixed DOI of 500 µs while the dwell time are varied from 100 up to 1000 µs. All tests are performed at the rail pressures of 500, 1000, 1500 and 2000 bar while the engine is operated at 1200 rpm. Results show that the injection rate shape of single injections is highly dependent on the rail pressure profile. With double split-injections, the rate of the second injection as well as the total fuel mass injected increases when the dwell time is shortened. Short dwell intervals boost the fuel quantities as a result of the altered needle response. Long dwell time between two equally-long injections generate similar injection rates. The injector hydraulic delay was more pronounced when dwell time was kept long enough. Overall, higher injection pressure advances the effective start of injection while retarding the effective end of injection.       ]]></description>
      <pubDate>Mon, 18 Nov 2019 17:15:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1653455</guid>
    </item>
    <item>
      <title>Measurement of Oil Film Pressure in Piston Pin-Boss by Thin-Film Pressure Sensor</title>
      <link>https://trid.trb.org/View/1595040</link>
      <description><![CDATA[Piston design approach for automotive engines has been advanced from both experimental and calculation analysis. However, the developments of experimental analysis method that can verify the accuracy of the calculation analysis are required. In this paper, multi-point thin-film pressure sensor for piston pin-boss part (hereinafter pin-boss) was sputtered on piston pin sliding surface and oil-film pressure distribution was measured in axial and circumferential direction using the pin-boss fatigue tester. Additionally, oil-film pressure measurement of the piston pin-boss portion was carried out without changing the environment of the measurement portion by using the thin-film pressure sensor. The authors also analyzed the application of elastic fluid lubrication theory using CAE analysis, compared with measured values．]]></description>
      <pubDate>Thu, 23 May 2019 10:23:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1595040</guid>
    </item>
    <item>
      <title>Analysis of Cylinder Pressure Measurement Accuracy for Internal Combustion Engine Control</title>
      <link>https://trid.trb.org/View/1462468</link>
      <description><![CDATA[With the tightening requirements on engine emission and performance, pressure based combustion controls are becoming common in medium speed large bore reciprocating internal combustion engines. The accuracy of the cylinder pressure data including the raw pressure value at its corresponding crank angle, has a vital impact on engine controllability. For instance, this work shows that a 1-bar pressure offset leads to a 0.6% variation in the total heat release (THR) while the 50% heat release crank angle (CA50) can be shifted by 1.5 degrees. Similarly, with a single degree error in the crank position, the indicated mean effective pressure (IMEP) gets a 1.8 bar error. Thus, in this work the typical errors for cylinder pressure measurement are reviewed and analyzed for large bore four stroke marine and power plant production engines.         The main sources of error for pressure measurement are thermal shock and installation defects. Meanwhile, calibration is carried out for ten production pressure transducers to provide a general accuracy result of the pressure transducers that are used in production engines.         The main sources of error for crank angle position monitoring - when done with a flywheel-based inductive system, manufacturing tolerance, installation, and the relative displacement between the pickups and the shaft due to shaft bending, shaft longitudinal movement, torsional vibration and engine block vibration are the main sources of error.         In this paper, those errors are quantified individually through simulation and their impacts on IMEP and CA50 are also presented. At last, cylinder volume deformation and its impact on combustion diagnostics are also estimated. From the result it is concluded that torsional vibration and cylinder volume deformation have the most significant effects for combustion analysis.       ]]></description>
      <pubDate>Tue, 30 Oct 2018 10:50:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1462468</guid>
    </item>
    <item>
      <title>Development of the Portable Combustion Monitor System Using the Fourier Series Type IMEP Calculation Method</title>
      <link>https://trid.trb.org/View/1512563</link>
      <description><![CDATA[For improvement of fuel consumption and the exhaust gas emission of automotive engines, the measurement of combustion conditions in the engine on the real vehicle tests are important as well as the engine test on the bench. In this study, the authors developed a portable combustion monitor system that can measure indicated mean effective pressure (IMEP) from plug washer type force sensor and ECU crank signal. As the result, they verified that IMEP can be measured with untoothed pulse and found a good correlation between equivalent IMEP from plug washer type force sensor and IMEP from ordinary pressure diagram.自動車用エンジンの燃費やエミッションの改善には，エンジン単体のみならず実車両での機関燃焼状態の計測が重要視されている．本研究では，点火プラグ座型力センサとECUクランク信号による図示平均有効圧計測を実車両で計測可能な車載型燃焼モニタ装置を開発した．その評価を行い，良好な結果が得られたので報告する．]]></description>
      <pubDate>Fri, 29 Jun 2018 17:12:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1512563</guid>
    </item>
    <item>
      <title>Analysis of Contact and Slip Behavior of Elements in Metal Pushing Belt CVT</title>
      <link>https://trid.trb.org/View/1512490</link>
      <description><![CDATA[The authors developed the thin-film pressure sensor which was improved durability by forming a film with DLC (Diamond-Like Carbon) or TiN (Titanium Nitride). Several sensors were put on the surface of a drive pulley in the pushing metal belt type of CVT, and then the contact and slip behavior between the pulley and elements which the belt consisted of were analyzed. It became possible to quantify the size of active arc area where the slip was generated and the relation of the slip speed versus the clamping force and the CVT transmitting torque.DLCやTiNにより耐久性を強化した薄膜圧力センサを新規開発し，このセンサをプッシュベルト式CVTのシーブ表面に複数点形成することにより，シーブとエレメント間の接触・スリップ挙動を解析した．シーブ挟圧や伝達トルクに対して，アクティブアーク領域の大きさやスリップ速度の定量化を可能にした．]]></description>
      <pubDate>Mon, 25 Jun 2018 13:49:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1512490</guid>
    </item>
    <item>
      <title>Effects of inlet radial distortion on the type of stall precursor in low-speed axial compressor</title>
      <link>https://trid.trb.org/View/1492309</link>
      <description><![CDATA[Experimental investigations of the effect of inlet blade loading on the rotating stall inception process are carried out on a single-stage low-speed axial compressor. Temporal pressure signals from the six high response pressure transducers are used for the analysis. Pressure variations at the hub are especially recorded during the stall inception process. Inlet blade loading is altered by installing metallic meshed distortion screens at the rotor upstream. Three sets of experiments are performed for the comparison of results, i.e. uniform inlet flow, tip, and hub distortions, respectively. Regardless of the type of distortion introduced to the inflow, the compressor undergoes a performance drop, which is more severe in the hub distortion case. Under the uniform inlet flow condition, stall inception is caused by the modal type disturbance while the stall precursor switched to spike type due to the highly loaded blade tip. In the presence of high blade loading at the hub, spike disappeared and the compressor once again witnessed a modal type disturbance. Hub pressure fluctuations are observed throughout the process when the stall is caused by a modal wave while no disturbance is noticed at the hub in spike type stall inception. It is believed that the hub flow separation contributes to the modal type of stall inception phenomenon. Results are also supported by the recently developed signal processing techniques for the stall inception study.]]></description>
      <pubDate>Wed, 27 Dec 2017 10:29:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1492309</guid>
    </item>
    <item>
      <title>Engine performance under pressure : in the age of electronically controlled engines, financially constrained ship operators and environmental regulation, reliable monitoring of cylinder pressure is more important than ever</title>
      <link>https://trid.trb.org/View/1465940</link>
      <description><![CDATA[]]></description>
      <pubDate>Mon, 01 May 2017 14:11:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1465940</guid>
    </item>
    <item>
      <title>Field Measurements of Lateral Earth Pressures on a Pre-Cast Panel Retaining Wall</title>
      <link>https://trid.trb.org/View/1428743</link>
      <description><![CDATA[Terra Tee pneumatic earth pressure cells are used to measure lateral earth pressures acting on a pre-cast panel retaining wall. Force transducers are used between the panel and the supporting structural members to measure the total force exerted on the panel by the backfill material. Accurate measurements of panel movements are made during and after backfilling. Data are presented for measured pressures, forces, and movements covering a period of 65 days. Physical and engineering properties of the backfill material are determined. Reasonably good correlation between the forces calculated from the pressure cell measurements and those measured by the force transducers tend to verify the adequacy of the pneumatic pressure cell calibration procedures. Measured pressures in the upper elevations of the wall correlate fairly well with theoretical pressures computed according to Coulomb and Rankine. However, measured pressures in the lower elevations are considerably higher than the theoretical pressures.]]></description>
      <pubDate>Wed, 09 Nov 2016 13:24:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1428743</guid>
    </item>
    <item>
      <title>Angle of Incidence Effects on Far-Field Positive and Negative Phase Blast Parameters</title>
      <link>https://trid.trb.org/View/1352470</link>
      <description><![CDATA[The blast overpressure acting on a rigid target is known to vary between the normally reflected overpressure and the incident overpressure as a function of the angle between the target and the direction of travel of the blast wave. Literature guidance for determining the exact effects of angle of incidence are unclear, particularly when considering the negative phase. This paper presents the results from a series of well controlled experiments where pressure transducers are used to record the pressure-time history acting on the face of a large, rigid target at various angles of incidence for varying sizes of hemispherical PE4 charge and stand-off distances. The test data demonstrated remarkable repeatability, and excellent agreement with semi-empirical predictions for normally reflected overpressures. The oblique results show that peak overpressure, impulse and duration are highly dependent on angle of incidence for the positive phase, and are invariant of angle of incidence for the negative phase.]]></description>
      <pubDate>Thu, 28 May 2015 09:23:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1352470</guid>
    </item>
    <item>
      <title>Evaluation of Surface and Subsurface Processes in Permeable Pavement Infiltration Trenches</title>
      <link>https://trid.trb.org/View/1341416</link>
      <description><![CDATA[The hydrologic performance of permeable pavement systems can be affected by clogging at the pavement surface and/or clogging at the interface where the subsurface storage layer meets the underlying soil. The objective of this paper was to evaluate changes in infiltration and exfiltration using three pressure transducers installed in piezometers along the length of two, 2.47-m wide, permeable pavement strips. Each system was retrofitted in the parking lane of a curb-and-gutter system in Louisville, Kentucky. The strips received run-on from a drainage area about 20–25 times larger than the paver area. Below each permeable pavement strip (16.8-m and 36.6-m long) was a deep (3.0 m) and narrow (0.6 m) infiltration trench. Piezometers were installed at the bottom of the trench about 1 m from the uphill edge, and at roughly one-third and two-thirds along the permeable paver strips, to measure the rise and fall of water for 13 months. Initially, infiltrating run-on was localized near the uphill edge. During periods with intense runoff, the localized inflow accumulated in the trench faster than it could move laterally creating a measureable subsurface gradient between piezometers. Runoff transported solids to the uphill edge where a portion was filtered and accumulated between the paver blocks. With time, surface clogging progressed along the paver strip past the next piezometer. The localized infiltration caused the subsurface water level gradient between piezometers to reverse. After each event, the exfiltration rate per wetted surface area was calculated for fixed 0.15-m intervals. The exfiltration rate decreased drastically after the first few events. The primary cause of the initial exfiltration rate decline was attributed to infiltrating water rinsing the fine solids attached to the washed aggregate and depositing them at the bottom of the trench. Silt and clay-sized particles (particle size smaller than 75 μm) accounted for about 1.7–1.8% of the washed aggregate mass. This large source of fine-grained particles from construction materials can be eliminated if cleaner aggregate is available and used. A continued and significant decrease in exfiltration rate with age was measured during year 1 of use. To optimize the design of these systems, a lifecycle analysis incorporating exfiltration rate decline with age should be included. Another item to consider during the design process is the variability of urban soils. Although these sites are across the street from one another, exfiltration rates were markedly different. Installation should be targeted in soils with larger hydraulic conductivities to improve hydrologic performance, so more preconstruction soil borings and soil tests are necessary to characterize the in situ soils.]]></description>
      <pubDate>Thu, 29 Jan 2015 09:17:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1341416</guid>
    </item>
    <item>
      <title>Simulation of shock wave propagation in a duct with a side branch</title>
      <link>https://trid.trb.org/View/1324514</link>
      <description><![CDATA[Experimental studies conducted during the 70s and 80s of the previous century are numerically simulated. The authors examine a horizontal duct with a vertical branch having a circular cross section whose diameter is 5 cm. These experiments were conducted by the late Dr Heilig in the Ernst-Mach-Institute (private communication). In both segments of the branched duct pressure transducers were installed. They were used for recording the pressure histories and for deducing the traveling shock wave speed. These results were compared with the present numerical simulation. The numerical simulations were conducted using the commercial code Fluent with the density-based AUSM solver. The solver is second order in both space and time. It is apparent from the results obtained that good agreement exists between the recorded pressure histories and their simulations. Based on the good agreement between recorded and simulated pressures a numerical study was conducted by comparison between two similar branched ducts, one having a circular cross section while the other has a rectangular cross section. Also, the effect that changes in the branched segment orientation have on the resulting flow field were investigated.]]></description>
      <pubDate>Wed, 29 Oct 2014 11:38:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1324514</guid>
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