scholarly journals Acceleration Characteristics of Starting Vehicles

2000 ◽  
Vol 1737 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Gary Long
Keyword(s):  
Field Measurements ◽  
Simulation Software ◽  
Rate Of Change ◽  
Model Parameters ◽  
Passenger Cars ◽  
Design Data ◽  
Vehicle Performance ◽  
Analysis And Design ◽  
Railroad Crossings ◽  
Green Book

Acceleration characteristics of starting vehicles are needed for many transportation analysis and design purposes involving driveways, turning bays, intersecting streets, traffic signals, railroad crossings, simulation software, and so forth. Constant acceleration is sometimes assumed, or AASHTO Green Book values based on piecewise-constant accelerations are sometimes adopted. However, continuing research has shown that linearly decreasing acceleration rates better represent both maximum vehicle acceleration capabilities and actual motorist behavior. It is not acceleration that usually is constant during speed changes; it is the rate of change in acceleration. The evolution of AASHTO acceleration values for design is traced, and the literature is reviewed for pertinent field observations. Linearly decreasing acceleration (and some deceleration) model parameters are calibrated for various sets of observational and design data. Despite published results from thousands of field measurements, the values selected for design were found to be based mostly on vehicle performance capabilities, with conjecture about how many of these capabilities are normally used by drivers. Design accelerations were found to deviate substantially from observed accelerations. At the start of motion, observed accelerations were about 15 percent faster for passenger cars and 45 percent faster for SU (single unit) trucks than design accelerations. As speed increased, observed accelerations dropped three to four times faster than design accelerations for these vehicles. Observed accelerations for WB-15 trucks began 40 percent to 75 percent slower than design accelerations, and they were considerably slower than the values in the Green Book for trucks at railroad crossings. Voids in the available information base are identified. Linearly decreasing design acceleration rates for motorists operating different classes of vehicles in different design situations are recommended, and revisions for Green Book parameters and charts are suggested. The recommended acceleration model greatly simplifies acceleration parameters but implies using different acceleration relationships for different design speeds instead of one for all.

Simulation and Simulation Software Development of the Braking Process of a Subway Train

2014 ◽  
Vol 556-562 ◽  
pp. 294-301 ◽  
Author(s):  
Long Han ◽  
Chun Tian ◽  
Yan Wang ◽  
Meng Ling Wu ◽  
Zhuo Jun Luo
Keyword(s):  
Computational Effort ◽  
Simulation Software ◽  
System Model ◽  
Brake System ◽  
Railway Vehicle ◽  
Model Parameters ◽  
Modeling Process ◽  
Time Simulation ◽  
Subway Train ◽  
Braking Process

This paper deals with the problem of braking process modeling. A subway train braking process simulation software is built, which composes of a GUI and a underlying model. The underlying model consists of a train model and a brake system model. The train model is simplified and built by assembling subcomponent element models of a railway vehicle. The brake system model is simplified and built based on experimental data in order to reduce computational effort. The GUI of the software can be use to input model parameters, display simulation results, and store simulation data. As a result of the simplifications of the modeling process, the developed software can perform real time simulation.

Design Guidance for Freeway Main-Line Ramp Terminals

2012 ◽  
Vol 2309 (1) ◽  
pp. 48-60 ◽  
Author(s):  
Darren J. Torbic ◽  
Jessica M. Hutton ◽  
Courtney D. Bokenkroger ◽  
Marcus A. Brewer
Keyword(s):  
Field Study ◽  
Driver Behavior ◽  
Main Line ◽  
Behavioral Study ◽  
Crash Analysis ◽  
Vehicle Performance ◽  
Green Book ◽  
Improved Design ◽  
Parallel Acceleration ◽  
Design Guidance

This paper presents the results of a study to develop improved design guidance for freeway main-line ramp terminals on the basis of modern driver behavior and vehicle performance capabilities. The primary steps included a crash analysis, an observational field study, and a driver behavioral study. This research reached several key conclusions, as follows. Vehicle merging speeds tend to be closer to freeway speeds at tapered acceleration lanes than at parallel acceleration lanes. The recommended minimum lengths for acceleration lanes presented in the 2004 edition of AASHTO's A Policy on Geometric Design of Highways and Streets (Green Book) are conservative and, under certain conditions, could be reduced by 15%. In a situation in which a significant volume of trucks uses an entrance ramp, an acceleration lane length that will better accommodate trucks can be derived by using speed–distance curves developed for a range of weight-to-power ratios. The recommended minimum lengths for deceleration lanes presented in the 2004 Green Book are conservative and do not account for deceleration in the freeway. Providing deceleration lanes longer than the minimum values given in the Green Book may promote casual deceleration by exiting drivers. Several potential changes for consideration in the next edition of the Green Book are recommended on the basis of the findings and conclusions of this research.

The Research of Marine Nuclear Power Two Loop Simulation Software Based on the Thermal System Analysis

2014 ◽  
Vol 983 ◽  
pp. 288-291
Author(s):  
Guo Lei Zhang ◽  
Xiang Dong Jin ◽  
Zhan Zhao ◽  
Zhi Jun Shi
Keyword(s):  
Nuclear Power ◽  
System Analysis ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Operating Conditions ◽  
Two Phase ◽  
Design Data ◽  
Software Optimization ◽  
Power Simulation ◽  
Basic Functions

To study of Nuclear power simulation software's basic functions and mathematical model based on thermal analysis. Describes the two-phase flow model of GSE software superiority, as well as the software optimization program .Use of software tools for normal operating conditions of the simulation calculation and analysis of the results. Comparison with design data shows that,the software use in marine nuclear power two loop system simulation analysis field, the accuracy of it is higher.

scholarly journals Energy Demand Analysis and Design of a Hybrid Power System in Bawean Islands, Indonesia

2018 ◽  
Vol 164 ◽  
pp. 01038
Author(s):  
Ridho Hantoro ◽  
Cahyun Budiono ◽  
Ronald Kipkoech Ketter ◽  
Nyoman Ade Satwika
Keyword(s):  
Power Systems ◽  
Energy Demand ◽  
Peak Load ◽  
Electricity Consumption ◽  
Simulation Software ◽  
Diesel Generator ◽  
Time Step ◽  
Analysis And Design ◽  
Optimum System ◽  
Hybrid Power

Over 70 000 000 people in Indonesia have no access to electricity. This study was carried out in Bawean Islands which are located in the Java Sea about 150 km North of Surabaya, the headquarters of East Java. The study to determine the energy services available in the Bawean Island was done through interviewing a random sample of 72 households in two villages namely Komalasa and Lebak. Based on the average monthly electricity consumption of the sampled households connected to the grid, a hybrid renewable energy based electrical supply system was designed for Gili Timur Island, one of the satellite islands around Bawean Island. The system was designed with the aid of a time step simulation software used to design and analyze hybrid power systems. A sensitivity analysis was also carried out on the optimum system to study the effects of variation in some of the system variables. HOMER suggests that for the expected peak load of 131 kW, an optimum system will consist of 150 kW from PV array, two wind turbines each rated 10 kW, a 75 kW diesel generator and batteries for storage.

scholarly journals Implications of sea-ice biogeochemistry for oceanic production and emissions of dimethyl sulfide in the Arctic

2017 ◽  
Vol 14 (12) ◽  
pp. 3129-3155 ◽  
Author(s):  
Hakase Hayashida ◽  
Nadja Steiner ◽  
Adam Monahan ◽  
Virginie Galindo ◽  
Martine Lizotte ◽  
...  
Keyword(s):  
Sea Ice ◽  
Water Column ◽  
Dimethyl Sulfide ◽  
Phytoplankton Bloom ◽  
Model Simulation ◽  
Field Measurements ◽  
Sulfur Cycle ◽  
The Arctic ◽  
Model Parameters ◽  
Ocean Ecosystem

Abstract. Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice–ocean ecosystem–sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP) on the oceanic production and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. Production and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea–air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m−2 d−1. Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS production and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of oceanic DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.

scholarly journals 1 DESIGN OF MODULAR ARCHITECTURE FOR EV AND HEV FOR PASSENGER CARS

2021 ◽  
Author(s):  
Midhun Muraleedharan ◽  
◽  
Amitabh Das ◽  
Dr. Mohammad Rafiq Agrewale ◽  
Dr. K.C. Vora ◽  
...  
Keyword(s):  
Neural Network ◽  
Energy Consumption ◽  
Fuel Consumption ◽  
Modular Architecture ◽  
Passenger Cars ◽  
Passenger Car ◽  
Vehicle Performance ◽  
Matlab Simulink ◽  
System Designer ◽  
Battery Energy

Hybridization is important to obtain the advantages of both the engine and motor as the sources of propulsion. This paper discusses the effect of hybridization of powertrain on vehicle performance. The Hybrid architectures are differentiated on the basis percentage of power dependency on the engine and motor. Passenger car with hybridization ratios of 20%, 40%, 60%, 80% and 100% are modelled on MATLAB/Simulink using the backward facing approach with the engine and motor specifications remaining constant. The hybridizations ratios and the energy consumption in terms of fuel and battery energy are obtained from the model and compared. Neural network is implemented to determine the fuel consumption. The outputs can be used by a system designer to determine a desirable hybridization factor based on the requirements dictated by the specific application.

scholarly journals Wedding Organizer Order Management

2014 ◽  
Vol 5 (2) ◽  
pp. 839
Author(s):  
Desi Maya Kristin ◽  
Yuliana Lisanti
Keyword(s):  
Information System ◽  
Data Collection ◽  
System Analysis ◽  
Qualitative Interviews ◽  
Literature Study ◽  
Design Data ◽  
Web Based ◽  
Analysis And Design ◽  
Order Management ◽  
The Web

This information system is used as a solution that can help to meet the requirements of the couples. The research methods are data collection, analysis and design. Data collection method implemented by surveys including interviews with 58 clients, 15 vendors, and 12 WO (Wedding Organizer) and by literature study that includes books and journal related. Object oriented is used as the method for system analysis and design. The result is a web based information system that connects vendors and clients in one online place. The web based application can be used to book the reception hall, catering food for guests, entertainments, bridal, car loan, prewed and receptions photos. The benefits of the web based applications are user can costumize or choose the packages, check the price information and get reports related to Wedding Organizer Order Management business process. The results of the qualitative interviews to 58 clients who already used the applications is the client get shorter time compare to clients who manage their own wedding reception.

scholarly journals Evaluation of a Scale-Resolving Methodology for the Multidimensional Simulation of GDI Sprays

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2699 ◽  
Author(s):  
Giovanni Di Ilio ◽  
Vesselin K. Krastev ◽  
Giacomo Falcucci
Keyword(s):  
Turbulence Modeling ◽  
Direct Injection ◽  
Test Procedure ◽  
Hybrid Approach ◽  
Development Trend ◽  
Standard Test ◽  
Gasoline Direct Injection ◽  
Model Parameters ◽  
Test Case ◽  
Passenger Cars

The introduction of new emissions tests in real driving conditions (Real Driving Emissions—RDE) as well as of improved harmonized laboratory tests (World Harmonised Light Vehicle Test Procedure—WLTP) is going to dramatically cut down NOx and particulate matter emissions for new car models that are intended to be fully Euro 6d compliant from 2020 onwards. Due to the technical challenges related to exhaust gases’ aftertreatment in small-size diesel engines, the current powertrain development trend for light passenger cars is shifted towards the application of different degrees of electrification to highly optimized gasoline direct injection (GDI) engines. As such, the importance of reliable multidimensional computational tools for GDI engine optimization is rapidly increasing. In the present paper, we assess a hybrid scale-resolving turbulence modeling technique for GDI fuel spray simulation, based on the Engine Combustion Network “Spray G” standard test case. Aspects such as the comparison with Reynolds-averaged methods and the sensitivity to the spray model parameters are discussed, and strengths and uncertainties of the analyzed hybrid approach are pointed out. The outcomes of this study serve as a basis for the evaluation of scale-resolving turbulence modeling options for the development of next-generation directly injected thermal engines.

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