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    <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" />
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    <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>
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    <item>
      <title>Research on dust diffusion reduction-control technology of wind guide hood system based on an improved tunnel pressurized air system</title>
      <link>https://trid.trb.org/View/2528976</link>
      <description><![CDATA[The dust generated during tunnel construction poses a serious threat to the health of construction workers. High dust concentrations rapidly spread throughout the tunnel, severely polluting the construction environment. To improve these conditions, the present study sought to develop a wind volume-wind direction guide device, hereinafter referred to as wind guide hood (WGH), which can regulate the pressure air volume in real time. The WGH ventilation and dust control system divides the wind volume into two parts while maintaining a total pressurized air volume of 500 m³/min. One part of the wind volume flows to the digging working face through a pressurized air cylinder, whereas the other part is discharged to the back side of the tunnel, thus achieving dust control. By separating the airflow, the system minimizes the airflow to the face, thereby slowing down dust diffusion. The results revealed that installing the WGH system effectively controls dust propagation. When the airflow to the face is 20 m³/min, the diffusion distance of high-concentration dust is reduced to 18.7 m, and the dust control efficiency is increased by 68.04 %, thereby greatly improving the working conditions within the tunnel.]]></description>
      <pubDate>Wed, 09 Apr 2025 09:52:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528976</guid>
    </item>
    <item>
      <title>Development and Construction of Soil Reinforcement Method Using Pressurized Injection Materials</title>
      <link>https://trid.trb.org/View/2342140</link>
      <description><![CDATA[The authors previously developed and proposed a new method called "Lotus anchor" method as a soil reinforcement method. "Lotus Anchor" developed as a soil reinforcement method is a method that obtains high pullout resistance by expanding the reinforcement material using pressurized injection. This paper reports on construction tests conducted during the development process of this method, evaluation of pullout resistance characteristics, examples of subsequent construction, and construction management methods aimed at further improving the efficiency and quality of this method.]]></description>
      <pubDate>Fri, 12 Apr 2024 09:16:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2342140</guid>
    </item>
    <item>
      <title>Evolution and Characterization of Pressurized Flow Conditions in Stormwater Collection Networks</title>
      <link>https://trid.trb.org/View/2319923</link>
      <description><![CDATA[Intense rain events and sprawling urbanization have contributed to more frequent flash flooding in cities, often due to the pressurization of drainage systems. Stormwater collection networks (SCNs) can become pressurized if their conveyance capacity is exceeded, leading to on-street flooding through backflow out of curb inlets. Due to the complexity of SCN geometry and spatiotemporal rainfall variability, studies evaluating pressurization in stormwater systems have previously been conducted for relatively simple geometries and inflow conditions. Thus, to date there have been few network-scale insights into how pressurization develops, making it difficult to understand drivers that influence pressurization: slope, roughness, connectivity, and inflow rate. The present work evaluates the process of SCN pressurization using numerical modeling through a systematic variation of these variables. Herein, three distinct pressurization mechanisms were identified by using EPA SWMM 5.1 to model idealized SCN topology and junction inflows. New nondimensional flow indexes (NDFIs) are proposed to characterize the pressurization conditions after an initially empty stormwater system reaches steady state under application of hydrographs. This study provides a basis for further systematic evaluation of factors influencing drainage system pressurization, guiding future actions to mitigate urban flash flooding.]]></description>
      <pubDate>Tue, 20 Feb 2024 09:15:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2319923</guid>
    </item>
    <item>
      <title>Theoretical analysis of local indentation by the wedge indenter for pressurised pipeline</title>
      <link>https://trid.trb.org/View/2169779</link>
      <description><![CDATA[External impact is one of the potential hazards for in-service subsea pipelines. The stress concentration by external impact can create a dent that affects the pipeline's ultimate bearing capacity. In this paper, a theoretical model based on the string-on-plastic foundation is established to model the local indentation of pressurised pipelines by a wedge indenter. The effects of internal pressure and boundary conditions on the denting process are investigated. With this model, the relationship between the indenting force and the dented depth is obtained under a set of two boundary conditions. The accuracy of the new analytical models is validated by comparing them with the specification and numerical simulation model. It is believed that the new analytical models will provide theoretical guidance for maintaining the reliability and integrity of in-service pressurised pipelines.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:57:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2169779</guid>
    </item>
    <item>
      <title>Effect of hexagonal stringer design on bulging factor and stress intensity factor of cracks in the skin of pressurized aircraft fuselage</title>
      <link>https://trid.trb.org/View/2117692</link>
      <description><![CDATA[Aircraft structural fatigue is a serious issue. Untreated, it could lead to failure. Several aircraft accidents were caused by widespread fatigue damage. For cracks in the fuselage, the stress state is due to the bulging around the crack caused by applied internal pressure. This condition is characterized by a parameter called the bulging factor; it compares the stress intensity factor of a crack in curved shell to its counterpart in a plate. Bulging factor expressions are available for longitudinal and circumferential cracks but less for slanted cracks.The underlying structure that stiffens the skin of the fuselage has a direct impact on the stress intensity factor and the bulging factor of the crack. A hexagonal grid stiffening pattern has been shown to provide sufficient stiffening to the fuselage skin while using a lesser amount of material compared to the traditional orthogonal grid design. However, the response of this grid pattern in the presence of a cracked fuselage has not been studied.The current paper aims to estimate the effect of the hexagonal grid pattern on the bulging factor and stress intensity factor of cracks of various lengths and orientations in the skin of the fuselage. Results obtained are compared to the conventional orthogonal grid stiffening pattern of a fuselage structure. Several patterns were considered. Results show that cracks of different lengths and orientations in hexagonal grid stiffened panels had stress intensity factors and bulging factors that are comparable to the base case within a margin of 2%–8%.]]></description>
      <pubDate>Mon, 27 Feb 2023 08:51:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2117692</guid>
    </item>
    <item>
      <title>Modeling and Simulation of a Fighter Aircraft Cabin Pressure Control System Using AMESim</title>
      <link>https://trid.trb.org/View/2046675</link>
      <description><![CDATA[Environmental Control System (ECS) of an aircraft provides required temperature, pressure and air flow to the cockpit or cabin or occupied compartments for the comfortable and required conditions of the occupant. Cabin pressure control system (CPCS), one of the sub-systems of ECS, controls and maintains the cabin pressure to provide a physiologically safe environment for the occupants inside the cabin. As ECS takes engine bleed air as input, any variation in engine rpm affects the cabin pressure and further the comfortable condition inside the cabin. This paper is focused on modeling and simulation of a fighter aircraft CPCS to evaluate its performance for its entire range of operation. The system is modeled and simulated in AMESim and the dynamic behavior of the system and its components are studied. Also, this paper emphasizes the effect of transient input characteristics on the cabin pressure with the cases of extreme variation in engine rpm and aircraft altitude. For the purpose of model validation, the simulated results are compared with the actual data and found that the simulated cabin pressure profile and the dynamics of cabin pressure control valve match with the actual data. The validated system model and results can be further used in designing a better CPCS.]]></description>
      <pubDate>Mon, 17 Oct 2022 17:00:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2046675</guid>
    </item>
    <item>
      <title>Modeling and Dynamic Analysis of a Self-Regulating Valve</title>
      <link>https://trid.trb.org/View/1969789</link>
      <description><![CDATA[Pressure regulating valves are one of the indispensable components in an aircraft. Its application is found in many critical systems such as anti-icing system, cabin pressurization, propulsion system, hydraulic system etc. In this study, the simulation and dynamic analysis of a pressure regulating anti-icing valve is discussed. The valve comprises of an arrangement of sliding piston and pressure chamber to regulate the pressure. It also includes a feedback loop to achieve self-regulation. The valve includes two functional halves for robustness as well as to have some redundant functionality if some components doesn’t function optimally as the operation calls for accuracy as well as precision. The principles behind the working of this valve includes the interaction of physical domains such as mechanical and fluid dynamics. The modeling of this valve is carried out in multi-domain physical state simulation in MATLAB/SIMULINK platform. It is followed by the dynamic analysis to study the effect of each sub-component on the overall functioning of the valve. Considering this model can be used for designing as well as solving field issues, all the variables such as the diameter at various sections, friction coefficient, surface area of piston, stroke length, orifice diameter are parametric. Variables such as inlet and outlet pressure, piston displacement, flow rate and force balance at the piston are studied. The response from the dynamic model with the initial parameters shows good correlation with the design targets and the influence of key physical parameters on outlet pressure and the regulation time is presented.]]></description>
      <pubDate>Tue, 31 May 2022 16:07:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1969789</guid>
    </item>
    <item>
      <title>Failure process analysis of frustum windows for deep-sea manned cabin</title>
      <link>https://trid.trb.org/View/1930595</link>
      <description><![CDATA[The commonly used acrylic frustum windows are the weakest components in the deep-sea manned cabin of the submersible. The short-term collapse test is typically required by full or scale model test, which can applied to measure the critical pressure but cannot tell when the structure begins to damage and how the damage continues. To make up for the deficiency, it is necessary to develop the design-by-analysis methodology. In this paper, numerical analysis for the pressurisation process of the frustum windows considering two failure criteria is carried out to capture the initial failure pressure and location. An effective way to study the detailed failure status and failure process of window under pressurisation is provided. The results are regressed as functions and compared with the values of conversion factor applied in window’s design based on ASME specification, which will provide reference for safe design based on determining safety factor reasonably.]]></description>
      <pubDate>Wed, 25 May 2022 09:40:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1930595</guid>
    </item>
    <item>
      <title>An Experimental Study of In-Cylinder Heat Transfer from a Pressurized Motored Engine with Varying Peak Bulk Gas Temperatures</title>
      <link>https://trid.trb.org/View/1937741</link>
      <description><![CDATA[The variation of in-cylinder heat transfer with parameters such as engine speed, air-to-fuel ratio, coolant temperature and compression ratio were frequently studied in classical research. These experimentally-obtained relationships are important for improving in-cylinder heat transfer models, essential in developing CO2 reducing strategies. In this publication, a 2.0 liter compression ignition engine was tested in the pressurized motored configuration. This developed experimental setup allowed testing of the engine at speeds ranging between 1400 rpm and 3000 rpm, with peak in-cylinder gas pressures from 40 bar to 100 bar. The engine was motored using different gas compositions chosen specifically to have ratios of specific heats of 1.40, 1.50, 1.60 and 1.67 at room temperature. This enabled motored testing with peak in-cylinder bulk gas temperatures ranging from 700 K to 1500 K. This wide variation of peak bulk gas temperature was achievable even at constant peak in-cylinder gas pressure, which gave the possibility of varying the thermal load of the engine independently from the gas pressure load. This experimental setup offered the repeatability and robustness of motored testing, with the benefit of a fired-representative gas pressure and thermal load. Throughout the test matrix, the engine was instrumented with eroding surface thermocouples at two locations in the cylinder head; at the cylinder central axis, and at the periphery in the squish region. The steady-state and transient components of heat flux were investigated separately, along with the average surface temperature and its swing. The transient component of heat flux was computed using the Impulse Response method, coupled with a two-dimensional finite element model of the eroding thermocouples, as presented in SAE 2021-24-0018. This method takes into account the two-dimensional nature of heat flux through the thermocouples and hence presents a more robust analysis than the more common one-dimensional treatment using the Fast-Fourier Transform method.]]></description>
      <pubDate>Thu, 14 Apr 2022 09:16:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1937741</guid>
    </item>
    <item>
      <title>Achieving an Improved Understanding of the Factors Affecting an Aircraft Environmental Control System by Coupling a 1D Cabin Air Distribution System Model with a 3D Passenger Cabin Model using Co-Simulation Middleware</title>
      <link>https://trid.trb.org/View/1819817</link>
      <description><![CDATA[Aircraft Environmental Control Systems (ECS) are designed to optimize passenger comfort by providing satisfactory cabin pressurization, and temperature and humidity control whilst minimising the risks to passenger health from airborne toxins and diseases.         The paper presents a case study that investigates how the cooling load discharge from an ECS system affects the flow behaviour inside a typical mid-size, wide-body aircraft passenger cabin. The investigation uses commercial off-the-shelf one dimensional (1D) Computational Fluid Dynamics (CFD) software to model the cooling pack, cabin air distribution system, and three quarters of the passenger cabin. The centre section of the cabin is modelled using a commercial off-the-shelf three dimensional (3D) CFD package, with the co-simulation middleware providing coupling adapters to ensure that two-way, bilateral exchange of boundary parameters between the 1D and the 3D CFD models gives continuity of mass and momentum transfer. The 1D and 3D CFD applications and Co-simulation middleware are supplied by 3 independent commercial organisations.         The results of the case study are discussed including the co-simulated ‘velocity field of the air discharge’ and the ‘temperature gradient inside the cabin’ within the 3D CFD model as well as the flow and temperature fields within the one-dimensional ECS cooling pack model. The paper concludes by discussing how the proper implementation of the co-simulation methods developed in this case study could bring significant benefits to engineering companies using CFD tools, including improved quality of simulation results and reduced simulation run times.]]></description>
      <pubDate>Thu, 09 Dec 2021 10:33:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1819817</guid>
    </item>
    <item>
      <title>Investigation of a Thermal Management of Manned Spacecraft</title>
      <link>https://trid.trb.org/View/1805187</link>
      <description><![CDATA[There are not only large amounts of energy, but also many different kinds of energy in manned spacecraft, which provide chance to optimize a thermal management system in the spacecraft. When water in atmosphere in pressured cabins was removed, waste heat in atmosphere was removed synchronously. Due to this phenomenon, a thermal management system, in which heat transfer in human zone and electrical equipment zone was considered together, was presented here. In the thermal management system, air loops in human zone and electrical equipments zone was reconstructed to decouple the waste heat and water removing processes, improve the heat exchange efficiency and make it possible to use waste heat produced by electrical equipments in other cabin with insufficient energy.]]></description>
      <pubDate>Thu, 09 Dec 2021 10:26:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1805187</guid>
    </item>
    <item>
      <title>Development of Air Supply Controller for FCV Based on Model-Based Development Approach</title>
      <link>https://trid.trb.org/View/1847343</link>
      <description><![CDATA[In Toyota’s 2nd generation FCV, an electric turbo-type air compressor has been adopted for downsizing and cost reduction. Automotive Fuel Cell applications present several challenges for implementing a turbo-type air compressor. When operating a fuel cell in high-temperature or high-altitude locations, the FC stack must be pressurized to prevent dry-up. The flow rate vs pressure conditions that the FC must pass through or in some cases operate at are typically within the surge region of a turbo-type air compressor. Additionally, Toyota requires quick air transient response (< 1 sec) for power generation, energy management, and FC dry-up prevention. If the turbo-type air compressor is not precisely controlled during quick transients, it can easily enter the surge region. To solve the above issues, we developed a new air supply controller which can avoid compressor surge by controlling 3 variables, ‘FC stack air flowrate’, ‘FC stack air pressure’, and ‘FC stack air Bypass’ independently with high accuracy. The controller was designed using a model-based development approach. At first, the physical characteristics of the air systems compressor, valves, pipes, and FC stack were modeled and integrated into a system level simulation that can run real-time on-board the vehicle Engine Control Unit (ECU). Next, the feedforward and feedback (PI) control were developed by implementing inverse models of the air system component equations. We confirmed that this control development approach could achieve Toyota’s air supply control performance requirements and prevent turbo-type air compressor surge.]]></description>
      <pubDate>Wed, 29 Sep 2021 09:31:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1847343</guid>
    </item>
    <item>
      <title>Reversible Peripheral Facial Nerve Palsy During Airplane Travel</title>
      <link>https://trid.trb.org/View/1745967</link>
      <description><![CDATA[Facial baroparesis is reversible palsy of the facial nerve that may occur due to a pressure change in the middle ear when ascending in an airplane or during scuba diving. The objective is to present a rare case of facial paresis during airplane travel. The authors report a 49-yr-old female patient who presented with a 30-min episode of transient right facial paresis with loss of taste during airplane travel. Brain magnetic resonance imaging (MRI) showed a small left parietal developmental venous anomaly, extensive inflammation of the paranasal sinuses, which were almost completely obstructed with thickened mucosa and mastoid cell secretion bilaterally. Nasal decongestants and antibiotics were prescribed. No new neurological signs or symptoms were noticed. Reversible facial baroparesis due to the pressure change in the middle ear should be considered in cases where present medical history includes ascent/airplane takeoff or prolonged diving and should not be mistaken for transitory ischemic attack.]]></description>
      <pubDate>Fri, 20 Nov 2020 11:06:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1745967</guid>
    </item>
    <item>
      <title>Aircraft Cabin Pressurization and Concern for Non-Arteritic Anterior Ischemic Optic Neuropathy</title>
      <link>https://trid.trb.org/View/1745968</link>
      <description><![CDATA[Cabin pressurization is the process by which aircraft maintain a comfortable and safe environment for passengers flying at high altitudes. At high altitudes, most patients can tolerate changes in pressurization; however, passengers at high risk of hypoxia may experience ischemic events. The purpose of this study was to evaluate variations in pressurization of commercial aircraft at cruising altitude and describe its relevance in relation to patients with non-arteritic anterior ischemic optic neuropathy (NAION). Altimeters were used to measure altitude and cabin altitude at cruising altitude aboard 113 commercial flights, including 53 narrow-body and 60 wide-body aircraft. Cabin altitude ranged from 4232 ft to 7956 ft at cruising altitudes ranging from 30,000 ft to 41,000 ft. The mean cabin altitude for all flights was 6309 876 ft. Narrow-body aircraft had a significantly higher mean cabin altitude (6739 829 ft) compared to wide-body aircraft (5929 733 ft). For all flights, the mean cruising altitude was 35,369 2881 ft with narrow-body aircraft cruising at a lower altitude of 34,238 2389 ft compared to wide-body aircraft at 36,369 2925 ft. Newer generation aircraft had a mean cabin altitude of 6066 837 ft, which was lower than the mean cabin altitude of older aircraft (6616 835 ft).Innovation in flight design has offered the ability for aircraft to fly at greater altitudes while maintaining lower cabin altitude. Those at high risk of hypoxia-induced complications may consider aircraft type when air travel is required.]]></description>
      <pubDate>Fri, 20 Nov 2020 11:06:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1745968</guid>
    </item>
    <item>
      <title>Marine Accident Brief: Overpressurization and Rupture of Cargo Tank on Cargo Vessel Fairchem Filly, May 30, 2019</title>
      <link>https://trid.trb.org/View/1707116</link>
      <description><![CDATA[On May 30, 2019, about 0750 local time, the Marshall Islands-flagged chemical tanker Fairchem Filly, with a crew of 22, experienced an overpressurization of the number 3 port and starboard cargo tanks while discharging liquid hexene at Vopak Terminal in Deer Park, Texas. The overpressurization resulted in damage to the number 3 port cargo tank and the tank top (deck). All cargo was contained on board the double-hulled vessel, with no pollution or injuries reported. Damage to the Fairchem Filly was estimated at $750,000, and the contaminated cargo was an estimated $100,000 loss. ​The National Transportation Safety Board determines that the probable cause of the overpressurization and rupture of the 3P cargo tank aboard the Fairchem Filly during offloading was the vessel and terminal personnel involved not following policies and procedures related to cargo discharge and nitrogen-blanketing operations. Contributing to the casualty was the lack of effective communication between the vessel and terminal personnel and the decision of the vessel’s PIC to continue discharge operations after being unable to communicate with the terminal.]]></description>
      <pubDate>Tue, 26 May 2020 10:17:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1707116</guid>
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