scholarly journals Analysis of the Wear Process of the Elements in the Braking System of Heavy Trucks

Author(s):  
Mădălin-Florin POPA ◽  
Bogdan Manolin JURCHIȘ

Today's commercial vehicles work in a very competitive environment, in an extremely active economic market and the requirements for the delivered performance make it imperative to study in detail each component element. In practice, all these aspects are found in the process of wearing the elements of different systems. Moreover, major changes are expected for the near future of motor vehicles in order to improve the ecological balance both by reducing the pollutant emissions of the propellants and by improving the percentage of recyclability and reduction of waste from maintenance (liquids and solutions such as oils, antifreeze or solutions with different detergents). In order to identify solutions to improve the mentioned problems, the current study analyses the types of wear identified in the elements of the braking system of commercial vehicles and their main factors of influence. The study is based on data obtained during analysis during operation for a number of trucks with different configurations.

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Xuebo Li ◽  
Jian Ma ◽  
Xuan Zhao ◽  
Lu Wang ◽  
Haichao Lan

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 938
Author(s):  
Hanwei Bao ◽  
Zaiyu Wang ◽  
Zihao Liu ◽  
Gangyan Li

In contrast to the traditional pneumatic braking system, the electronic-controlled pneumatic braking system of commercial vehicles is a new system and can remedy the defects of the conventional braking system, such as long response time and low control accuracy. Additionally, it can adapt to the needs and development of autonomous driving. As the key pressure regulating component in electronic-controlled pneumatic braking system of commercial vehicles, automatic pressure regulating valves can quickly and accurately control the braking pressure in real time through an electronic control method. By aiming at improving driving comfort on the premise of ensuring braking security, this paper took the automatic pressure regulating valve as the research object and studied the pressure change rate during the braking process. First, the characteristics of the automatic pressure regulating valve and the concept of the pressure change rate were elaborated. Then, with the volume change of automatic pressure regulating valve in consideration, the mathematical model based on gas dynamics and the association model between pressure change rate and vehicle dynamic model was established in MATLAB/Simulink and analyzed. Next, through the experimental test of a sample product, the mathematical models have been verified. Finally, the key structure parameters affecting the pressure change rate of the automatic pressure regulating valve and the influence law have been identified; therefore, appropriate design advice and theoretical support have been provided to improve driving comfort.


Author(s):  
Michelle N. Rosado-Pérez ◽  
Karen Ríos-Soto

Asthma is a respiratory disease that affects the lungs, with a prevalence of 339.4 million people worldwide [G. Marks, N. Pearce, D. Strachan, I. Asher and P. Ellwood, The Global Asthma Report 2018, globalasthmareport.org (2018)]. Many factors contribute to the high prevalence of asthma, but with the rise of the industrial age, air pollutants have become one of the main Ultrafine particles (UFPs), which are a type of air pollutant that can affect asthmatics the most. These UFPs originate primarily from the combustion of motor vehicles [P. Solomon, Ultrafine particles in ambient air. EM: Air and Waste Management Association’s Magazine for Environmental Managers (2012)] and although in certain places some regulations to control their emission have been implemented they might not be enough. In this work, a mathematical model of reaction–diffusion type is constructed to study how UFPs grow and disperse in the environment and in turn how they affect an asthmatic population. Part of our focus is on the existence of traveling wave solutions and their minimum asymptotic speed of pollutant propagation [Formula: see text]. Through the analysis of the model it was possible to identify the necessary threshold conditions to control the pollutant emissions and consequently reduce the asthma episodes in the population. Analytical and numerical results from this work prove how harmful the UFEs are for the asthmatic population and how they can exacerbate their asthma episodes.


Author(s):  
Candace Brown ◽  
Nancy Kennedy ◽  
Don Wright ◽  
Walt Zak

Described is one specific effort to better estimate commercial motor vehicle-related exposure at the state level in order to better determine commercial motor vehicle-related crash rates for state and federal programs. Limitations in the crash and exposure data affect the Federal Motor Carrier Safety Administration and a state’s ability to plan and assess operations and conduct ongoing analyses of program effectiveness. One important limitation has been the lack of reliable estimates of commercial motor vehicle exposure data at the state level. Exposure data, for the purpose of this report, are defined as the number of truck and bus vehicle miles traveled (VMT). Described is the methodology that was developed to calculate adjusted state VMT for commercial vehicles; results are presented for 1999 and 2000. The results support estimation of crash involvement rates for each state and provide exposure data for other analytical studies. The methodology to calculate adjusted state VMT for commercial motor vehicles has resulted in improved information resources in support of all crash analyses. The adjusted state VMT for commercial vehicles supports measurement of program effectiveness and development of countermeasures to promote motor carrier safety. The adjusted state VMT for commercial motor vehicles methodology and the commercial vehicle fatal-crash involvement rate reports enable state and federal agencies to better focus their safety programs and enforcement resources.


2020 ◽  
Vol 12 (10) ◽  
pp. 4111 ◽  
Author(s):  
Yifeng Xue ◽  
Xizi Cao ◽  
Yi Ai ◽  
Kangli Xu ◽  
Yichen Zhang

Air pollutant emissions from vehicles, railways, and aircraft for freight and passenger transportation are major sources of air pollution, and strongly impact the air quality of Beijing, China. To better understand the variation characteristics of these emissions, we used the emission factor method to quantitatively determine the air pollutant emissions from the transportation sector. The emission intensity of different modes of transportation was estimated, and measures are proposed to prevent and control air pollutants emitted from the transportation sector. The results showed that air pollutant emissions from the transportation sector have been decreasing year by year as a result of the reduction in emissions from motor vehicles, benefiting from the structural adjustment of motor vehicles. A comparison of the emission intensity of primary air pollutants from different modes of transportation showed that the emission level of railway transportation was much lower than that of road transportation. However, Beijing relies heavily on road transportation, with road freight transportation accounting for 96% of freight transportation, whereas the proportion of railway transportation was low. Primary air pollutants from the transportation sector contributed significantly to the total emissions in Beijing. The proportion of NOX emissions increased from 54% in 2013 to 58% in 2018. To reduce air pollutant emissions from the transportation sector, further adjustments and optimization of the structure of transportation in Beijing are needed. As for the control of motor vehicle pollutant emissions, vehicle composition must be adjusted and the development of clean energy must be promoted, as well as the replacement of diesel vehicles with electric vehicles for passenger and freight transportation.


1992 ◽  
Vol 3 (2) ◽  
pp. 133-147
Author(s):  
M.M. Elkotb ◽  
O.M.F. Elbahar ◽  
T.A. Abdou Ahmed ◽  
T.W. Abou-Arab

A mathematical model for the prediction of pollutant emissions from motor vehicles is presented. The model is based on the numerical solution of the three-dimensional equation representing the mass conservation of dilute diffusing species. The variation of wind speed and eddy diffusivity with height is taken into consideration. The three-dimensional diffusion equation is solved numerically. The numerical procedure involves the discretization of the partial differential equation using the finite volume approach. The resulting set of discretization equation is solved iteratively using a fully implicit solution procedure. Furthermore, field measurements of the concentrations of nitrogen oxide in the downtown area of Cairo were conducted. For this purpose, a mobile air pollution laboratory fitted with gas analyzers, particulate matter sampler and equipment for the measurement of wind speed and direction has been used. This laboratory is also fitted with data recording and monitoring facility. The mathematical model is tested by comparing the computed pollutant concentrations with the experimental data obtained from the field measurements in the Cairo Metropolitan Area.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wen-jie Zou ◽  
Tai-Yu Lin ◽  
Yung-ho Chiu ◽  
Ting Teng ◽  
Kuei Ying Huang

Finding the balance between economic development and environmental protection is a major problem for many countries around the world. Air pollution caused by economic growth has caused serious damage to humans’ living environment, and as improving energy and resource efficiencies is the first priority, many countries are targeting to move towards a sustainable environment and economic development. This study uses the modified dynamic SBM (slack-based measure) model to explore the economic efficiency and air pollutants emission efficiency in Taiwan’s counties and cities from 2012 to 2015 by taking labor, motor vehicles, and electricity consumption as inputs and average disposable income as output. Particulate matter (PM2.5), nitrogen oxide emissions (NO2), and sulfur oxide emissions (SO2) are undesirable outputs, whereas factory fixed assets are a carry-over variable, and the results show the following: (1) the regions with the best overall efficiency between 2012 and 2015 include Taipei City, Keelung City, Hsinchu City, Chiayi City, and Taitung County; (2) in counties and cities with poor overall efficiency performance, the average disposable income per household has no significant relationship with air pollutant emissions; (3) in counties and cities where overall efficiency is poor, the average efficiency of each household’s disposable income is small; and (4) except for the five counties and cities with the best overall performance, the three air pollutants in the other fourteen counties and cities are high. Overall, the air pollution of most areas needs improvement.


2018 ◽  
Vol 245 ◽  
pp. 07008 ◽  
Author(s):  
Dario Barsi ◽  
Carlo Costa ◽  
Francesca Satta ◽  
Pietro Zunino ◽  
Vitaly Sergeev

The objective of energy production with low environmental impact will have, in the near future, high potential of development also for naval applications. The containment of pollutant emissions can be achieved by the combined use of an innovative mini gas-steam combined cycle with thermal energy cogeneration to feed the ship thermal utilities, in place of the current Diesel engine application, and liquefied natural gas as fuel (LNG). The present work is focused on the definition of the architecture of the plant, by selecting optimal distribution of pressure and temperature and repartition of power between Gas Turbine (GT), Steam Turbine (ST) and thermal utilities, as well as on the choice and sizing of the individual components. The main purpose is the definition of a compact, high efficiency, system. The proposed basic mini-cycle ranges from 2 MW to 10 MW electric power. Thanks to the combined heat and power cogeneration plant adopted, for an overall electrical efficiency of about 30%, a total return (thermal + electricity) of about 75% can be achieved. An example of plant providing large power, in a partially modular arrangement is also proposed.


2019 ◽  
Vol 26 (3/4) ◽  
pp. 268 ◽  
Author(s):  
Hongyu Zheng ◽  
Shenao Ma ◽  
Lingxiao Fang ◽  
Weiqiang Zhao ◽  
Tianjun Zhu

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