2,102 research outputs found

    Integrating virtual reality and Building Information Modeling for improving highway tunnel emergency response training

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    During the last two decades, managers have been applying Building Information Modeling (BIM) to improve the quality of management as well as operation. The effectiveness of applications within a BIM environment is restrained by the limited immersive experience in virtual environments. Defined as the immersive visualization of virtual scenes, Virtual Reality (VR) is an emerging technology that can be actively explored to expand BIM to more usage. This paper highlights the need for a structured methodology for the integration of BIM/VR and gives a generic review of BIM and VR in training platforms for management in infrastructures. The rationales for fire evacuation training were formed based on the review. Then, methods of configuring BIM + VR prototypes were formulated for emergency response in highway tunnels. Furthermore, a conceptual framework integrating BIM with VR was proposed to enable the visualization of the physical context in real-time during the training. The result indicated that, extended to the training system of highway management via the “hand” of BIM, the VR solution can benefit more areas, such as the cost of fire evacuation drills in highway tunnels and the tendency of accidents to occur in the emergency response

    Aerodynamic Analysis on the Effects of Frontal Deflector on a Truck by using Ansys Software

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    Since the early years of the 20th century, when commercial vehicle mass production began, it has been found that air resistance plays a major factor related to vehicle motion. The main causes of aerodynamic drag for automotive vehicles are the flow separation at the rear end of the vehicles. By reducing the drag force, it is possible to increase the fuel economy. Aerodynamic component i.e. Frontal Deflectors (FD) commonly used on trucks to prevent flow separation. Frontal Deflectors themselves do create the drag, but they also reduce drags by preventing flow separation at downstream. The main aim of this paper is to quantify the effect of frontal deflectors on improving trucks aerodynamics. In this study, the simulation ran for 6 different shapes of FD which acquires different height and different placement of FD that is mounted on the truck from the frontal roof by using ANSYS Fluent software. The design of the truck has been done in SOLIDWORK 2018 and the same design is used for analysis in ANSYS (Fluent). The two-equation models used in this study are 𑘠− 𜀠with applying the Reynolds-averaged Navier Stokes (RANS) equations for the behaviour of fluid flow around the truck. The Reynolds number used is ð‘…ð‘’ = 1.1 × 106.  Based on the result, all the FD’s resulted in a reduction of coefficient of drag. The drag coefficient of all models differs. The velocity streamline acquired is different between the Frontal Deflector models mounted on the truck and the flow structure and vortex formation differs in various pattern formation. FD 4 produces the least value of drag. Hence, the efficiency of the truck improves. Therefore, FD 4 is the best model as the acquired coefficient of drag is 0.508 with the height (15 mm) and placement of (230 mm) is the best FD to be used on a truck. Consequently, the drag reduction percentage of FD 4 compared to the truck without a FD is 32.2%.&nbsp

    Integrated modeling and analysis methodologies for architecture-level vehicle design.

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    In order to satisfy customer expectations, a ground vehicle must be designed to meet a broad range of performance requirements. A satisfactory vehicle design process implements a set of requirements reflecting necessary, but perhaps not sufficient conditions for assuring success in a highly competitive market. An optimal architecture-level vehicle design configuration is one of the most important of these requirements. A basic layout that is efficient and flexible permits significant reductions in the time needed to complete the product development cycle, with commensurate reductions in cost. Unfortunately, architecture-level design is the most abstract phase of the design process. The high-level concepts that characterize these designs do not lend themselves to traditional analyses normally used to characterize, assess, and optimize designs later in the development cycle. This research addresses the need for architecture-level design abstractions that can be used to support ground vehicle development. The work begins with a rigorous description of hierarchical function-based abstractions representing not the physical configuration of the elements of a vehicle, but their function within the design space. The hierarchical nature of the abstractions lends itself to object orientation - convenient for software implementation purposes - as well as description of components, assemblies, feature groupings based on non-structural interactions, and eventually, full vehicles. Unlike the traditional early-design abstractions, the completeness of our function-based hierarchical abstractions, including their interactions, allows their use as a starting point for the derivation of analysis models. The scope of the research in this dissertation includes development of meshing algorithms for abstract structural models, a rigid-body analysis engine, and a fatigue analysis module. It is expected that the results obtained in this study will move systematic design and analysis to the earliest phases of the vehicle development process, leading to more highly optimized architectures, and eventually, better ground vehicles. This work shows that architecture level abstractions in many cases are better suited for life cycle support than geometric CAD models. Finally, substituting modeling, simulation, and optimization for intuition and guesswork will do much to mitigate the risk inherent in large projects by minimizing the possibility of incorporating irrevocably compromised architecture elements into a vehicle design that no amount of detail-level reengineering can undo

    Spatial and Temporal Investigation of Real World Crosswind Effects on Transient Aerodynamic Drag Losses in Heavy Duty Truck Trailers in the US

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    Decreasing truck fuel usage and climate change gas production is of national and global importance. This study focuses on large, heavy-duty on-road tractor trailer combinations because of their impact in terms of fuel consumption levels, emissions, and their dominance in freight transportation in the United States, which offers substantial potential to improve efficiency of the transportation sector and reduce emissions. The US Department of Energy completed a study of this topic in 2009, and the EPA and NHTSA are both engaged in regulating truck efficiency. The Energy Information Administration (EIA) reported that more than 50 percent of the total diesel consumed was for transportation and this percentage will increase. With about 65 percent of the total engine-out energy consumed by a typical heavy-duty tractor trailer being spent on overcoming aerodynamic drag at highway speeds (55mph in the USA), improvements to aerodynamic performance offers a substantial avenue for reduction in fuel usage and emissions. Besides being directly related to fuel consumption, emissions, maximum speed and acceleration, aerodynamic phenomena also influence the stability characteristics of road vehicles, and their response to crosswinds. Crosswinds from any directions will affect the drag losses and will cause a significant change in pressure distribution along the truck body. The main objective of this research is to provide a better understanding of the influence of crosswinds on the aerodynamic performance of heavy-duty tractor trailers in the United States.;A model to calculate on-road crosswinds for any temporal and spatial conditions from time-varying weather data, vehicle position and road data was developed. This transient model combined with drag data obtained from experimental, steady-state wind tunnel testing and numerical simulations for various tractor trailer configurations, the transient nature of coefficient of drag due to on-road crosswind conditions (from the model) was analyzed. Variations in yaw angle of up to 17 degrees were observed in some cases where the average yaw angle was recorded at only 3 degrees. Relationships between wind speed, yaw angle, drag and overall truck efficiency were clearly established. The research statistically measured the interaction between aerodynamic add-on devices, on-road crosswinds, and drag reduction efficiency. A region-based and time-based analysis was conducted to provide a better understanding of the aerodynamic performance of a baseline tractor-trailer configuration and aerodynamic add on devices. In several cases, the coefficient of drag varied as much as 60% on the routes analyzed and reductions in aerodynamic drag force up to 25% could realized by using the appropriate aerodynamic configurations. The application of these results will improve the estimation accuracy in fuel, emissions prediction models by allowing temporally and spatially disaggregated data input parameters. Finally, the study presented the different methods in which coefficient of drag is estimated and how these differences could play a role in misleading information about the aerodynamic characteristics of a tractor trailer

    Aerodynamic Analysis on the Effects of Frontal Deflector on a Truck by using Ansys Software

    Get PDF
    Since the early years of the 20th century, when commercial vehicle mass production began, it has been found that air resistance plays a major factor related to vehicle motion. The main causes of aerodynamic drag for automotive vehicles are the flow separation at the rear end of the vehicles. By reducing the drag force, it is possible to increase the fuel economy. Aerodynamic component i.e. Frontal Deflectors (FD) commonly used on trucks to prevent flow separation. Frontal Deflectors themselves do create the drag, but they also reduce drags by preventing flow separation at downstream. The main aim of this paper is to quantify the effect of frontal deflectors on improving trucks aerodynamics. In this study, the simulation ran for 6 different shapes of FD which acquires different height and different placement of FD that is mounted on the truck from the frontal roof by using ANSYS Fluent software. The design of the truck has been done in SOLIDWORK 2018 and the same design is used for analysis in ANSYS (Fluent). The two-equation models used in this study are 𑘠− 𜀠with applying the Reynolds-averaged Navier Stokes (RANS) equations for the behaviour of fluid flow around the truck. The Reynolds number used is ð‘…ð‘’ = 1.1 × 106.  Based on the result, all the FD’s resulted in a reduction of coefficient of drag. The drag coefficient of all models differs. The velocity streamline acquired is different between the Frontal Deflector models mounted on the truck and the flow structure and vortex formation differs in various pattern formation. FD 4 produces the least value of drag. Hence, the efficiency of the truck improves. Therefore, FD 4 is the best model as the acquired coefficient of drag is 0.508 with the height (15 mm) and placement of (230 mm) is the best FD to be used on a truck. Consequently, the drag reduction percentage of FD 4 compared to the truck without a FD is 32.2%.&nbsp

    EFFECT OF NITROGEN FILLING ON TIRE ROLLING RESISTANCE AND VEHICLE FUEL ECONOMY

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    There are various losses associated with passenger vehicle that affect its fuel economy as it is being operated. These losses include engine, driveline, aerodynamic and rolling losses. While engine, driveline and aerodynamic losses are inherent with the vehicle due to large number of parts that go into assembling, rolling loss is associated with the vehicle tires and it is the only part of the vehicle that comes in contact with the road. The rolling resistance of inflated tires is an important component of resistance to vehicle motion and contributes to vehicle fuel consumption. Many research works have been focused on how the various tire parameters (e.g., load, inflation pressure and speed) affect rolling resistance so that fuel economy can be increased. Recent studies indicate that inflating tire with nitrogen can maintain proper inflation pressure and decrease the deterioration of the rubber. Therefore, the goal of this research is to explore the probability of using nitrogen inflated tires to improve vehicle safety, performance, and reduce operating cost. In order to accomplish these goals, literature review was done to study the characteristics of tire and methods to improve the vehicle fuel economy and increase tire life. Based on this, a mathematical model was developed and refined to predict the rolling resistance of tires identifying the key parameters affecting them. Considering the possibility of inflating tires with nitrogen, the pressure sustainability of the inflation gas in tires at different operating conditions was tested. However, this does not represent the real driving conditions. Putting to test the tires filled with nitrogen under driving conditions would further help understand tire behavior and how this would affect the tire contact patch area with time. Comparing the test results of nitrogen inflated tires with air inflated ones was performed to determine the importance of nitrogen inflation to cut down the cost spent on fuel and replacement tires. Extensive shop testing was done at MARC (Michelin America Research Corporation) on different passenger car and truck tires. Qleak tests were conducted at room temperature for 16 days, while Sleak tests were performed at higher oven temperatures for about 28 days. It was observed that nitrogen inflation can maintain tire pressure approximately 35% to 55% better than air inflated tires for Qleak tests and about 29% to 35% better for Sleak test depending on tire type. In order to better understand the problem at hand, road testing was also performed on Wal-Mart truck fleet by inflating the tires with both air and nitrogen gases. The results demonstrated that nitrogen inflated tires improve tire life by about 50% and vehicle fuel economy by 23%. Considering these experimental results and extensive computer simulations, it was proven that nitrogen filling in tires help improve tire life and vehicle fuel economy

    Effects of duty cycles on diesel engine component life estimation

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    Engine manufactures have relied on over designed of engines and performance testing to ensure product reliability. The efforts to maximize efficiency and to predict performance characteristics have evoked an interest to study the in-cylinder pressure throughout the respective duty cycle. The duty cycle of an engine is defined as the history of speed and load conditions over which the engine operates in a specific application. Understanding the transient on-road diesel engine duty cycles has been one of major goals for the engine developers. To date there have not been any research performed to identify a wide variety of on-road diesel engine duty cycles. One of the world largest diesel engine manufactures, Cummins Inc., had interest in developing and understanding how the effective life of a diesel engine component is related to its duty cycle. West Virginia University Engine and Emissions Research Laboratory (EERL) was commissioned to conduct this study.;The objective of this study is to create a mathematical model that predicts the effective life of diesel engine components with respect to its operational duty cycle. In particular, power cylinder components were considered along with the variations of in-cylinder pressure. Four different duty cycles were evaluated in this study: a concrete mixer, heavy hauler, dump truck, and a transit bus. In-cylinder pressure data for all four duty cycles were statistically analyzed using the tools from non-parametric function and regression analysis. A mathematical model that predicts the power cylinder component lives was created. Mimicking the infield operation, heavy hauler displays the minimum power cylinder component life, while concrete mixer has the maximum life. Ultimately, this mathematical model will enable the engine manufactures to produce more cost effective components for different duty cycle applications, while fulfilling the customer requirements

    Solid Waste Collection Vehicle Route Optimization for the City of Redlands, California

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    The City of Redlands, California was interested in using a geographic information system (GIS) to help determine cost savings for the collection and transportation of its solid waste. Studies have shown that 60% - 80% of a municipality’s waste budget goes towards the collection and transportation phase. The city maintains a GIS department and they would like to incorporate data, procedures and a workflow to help facilitate using GIS to optimize solid waste collection. GIS technology can be used to help determine optimal collection routes by matching real world travel conditions and patterns. This study used a GIS to model current and proposed collection patterns using Esri’s ArcGIS Network Analyst software. The software was used to determine optimal routes for small collection groups and outlines the workflow and best practices for future analysis throughout the city

    Lightweight Composite Materials for Heavy Duty Vehicles

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    Aerodynamic Design Of A Roof Fairing For Trucks

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    Carbon emission is the release of carbon into the atmosphere also known as greenhouse gas emissions is the main contributor to climate change in this world. In Malaysia, the transportation sector accounts for around 28% of total carbon emission, of which 85% comes from road transport (Mustapa & Bekhet, 2016). Therefore, it is important reduce the greenhouse gas (GHG) emissions to slow the climate change and also improve air quality. Drag reducing devices can help to decrease air resistance of a vehicles, thus the forces acting on the vehicles will be transfer more of that power produced by the engine into movement. Therefore, the purpose of this thesis is to study how the air flow behavior imposed on the truck with 20 m/s of velocity by simulation. Moreover, wind tunnel is used to observe the drag acting on the 3D model truck that are selected. Multiple velocities is used from 1 m/s to 15 m/s to observe the drag. The result shows that a cab roof fairing that has rounded edges at the end could help to decrease the aerodynamic drag. In the simulation, the gap between the truck and trailer has created a low-pressure area which also contribute to the aerodynamic drag. Therefore, the use of cab roof fairing in the experiment, aerodynamic drag is reduced for about 5.86% at the velocity of 15 m/s
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