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Journal articles on the topic 'Air Brakes'
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1
Listiyono, Listiyono, Nurhadi Nurhadi, and Khambali Khambali. "Compressor Air Pressure and Brake Shield Distance Brake to Braking Accuracy on Brakes Antilock Braking System." Asian Journal Science and Engineering 1, no. 1 (June 30, 2022): 37. http://dx.doi.org/10.51278/ajse.v1i1.419.
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The development of automotive technology to date is very fast. In the city, it is almost rare to find conventional cars. Most are already using modern technology. The hallmark of modern cars is that they are not fully mechanical. Already combined with several electric and pneumatic tools. Until now the development in the field of chassis is endless. Its initial development began with the discovery of ABS (Anti Lock Brake System) brakes. Basically, ABS is followed by supporting components such as EBD, ESP, and so on.All of this is actually inseparable from the main function of braking. Namely so that the car can run well,, deceleration and stop as desired appropriately. The parts of the brakes that are most influential are the brake shoes and discs and the compressed air from the brakes. Also the most influential accuracy is the distance of the brake shroud. Therefore, in this study the aims of 1. To find the effect of pressure and brake shroud distance. 2. What is the minimum air pressure and brake shroud for the brakes to work properly (grip). This research uses experimental design method. The data is processed with the Minitab program. Data processing shows that: 1. The braking speed is influenced by the amount of compressed air pressure. Partially the distance of the brake shroud does not affect the braking speed. But the interaction of pressure and shroud distance has an effect on braking speed. 2. Air pressure that can be used as a fast ABS braking process is 3.75 – 4.25 (bar) with a shroud distance of 5 (mm).
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Scheibe, Robert R., and Per G. Reinhall. "Safety Monitoring of Air Brake Systems on Board Commercial Vehicles." Transportation Research Record: Journal of the Transportation Research Board 1560, no. 1 (January 1996): 40–47. http://dx.doi.org/10.1177/0361198196156000107.
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Research is leading to development of an on-board, intelligent air brake warning device (IBWD) for commercial vehicles equipped with such brakes. Recent statistics show that a disturbing proportion of commercial vehicles are operating with brakes that are out of adjustment or otherwise improperly maintained. Air brake systems on multiaxle vehicles are particularly sensitive to brake adjustment and provide poor feedback of deteriorating performance to drivers. Currently, the only active warning is for low air pressure; drivers receive no information about the effectiveness of the total system. Recent improvements, including automatic slack adjusters and antilock brake systems, are not sufficient to ensure adequacy of brakes. IBWD performs an on-board, real-time assessment of vehicle brake performance through measurement of a relatively small number of parameters. It gives drivers adequate time for corrective action and provides maintenance personnel and authorities with valuable information for improved servicing and inspection activities. In addition to the safety benefits, IBWD will enhance commercial vehicle productivity by reducing unnecessary delays at inspection points and by boosting overall acceptance of other intelligent transportation system technologies. A discussion of IBWD design philosophy and methodology is presented. The measurable parameters of interest are discussed, along with how they will be monitored. Analysis and modeling of empirical data collected from an extensive full-scale vehicle test program are presented, along with techniques for deriving a brake assessment algorithm.
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Duraisivam, Sivam, and E. Jamuna. "Thermal Analysis and Fabrication of Split Shoe Drum Brake." Applied Mechanics and Materials 867 (July 2017): 239–44. http://dx.doi.org/10.4028/www.scientific.net/amm.867.239.
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Active control of vehicle dynamics has become one of the top competitive features in today’s automobiles. Vehicle dynamics control systems include effective brakes and the number of life loss has been increased due to the in effective brakes. To reduce the crashing of vehicles caused by the braking disability by overcoming the drawbacks of the conventional braking system.Brakes are employed to stop or slow down the speed of the vehicle depending upon the driving needs. When brake applied, each wheel of the vehicle builds-up a certain braking force. For this reason, greater the number of wheels braked, greater will be the braking effect, and sooner the vehicle comes to halt. With this in mind the existing air brake system of a 6 wheeler is studied and analyzed. Brake shoe assembly is completely modeled using solid works and the analysis of the brake shoe assembly is carried out in Ansys .The results are analyzed . Then redesigned brake shoe assembly is modeled in solid works and analyzed with certain changes as required.
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Zuo, Jianyong, Jingxian Ding, Cheng Liu, and Zhuojun Luo. "A virtual prototype for performance analysis of electropneumatic brake on metro trains." Advances in Mechanical Engineering 12, no. 6 (June 2020): 168781402092627. http://dx.doi.org/10.1177/1687814020926275.
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In order to facilitate system design and performance analysis, a virtual prototype for metro train electropneumatic brakes is proposed. A virtual braking environment that consists of a three-car train model and six electropneumatic brakes model is elaborated. The virtual braking environment can be used to research the relation between braking response and electropneumatic brake’s parameters and to simulate axle loading transfer. By comparing the simulation results with bench test data, the electropneumatic brake model is proven to be quite accurate. Based on the proposed virtual prototype, a test train brake is designed, and a couple of field tests are carried out. The average deceleration of electropneumatic compound service brake at the initial speed of 45 km/h is 0.83 m/s2, the braking distance is 94 m, and that of pure air service brake at the speed of 43 km/h is 0.64 m/s2, the braking distance is 111 m. The field test results satisfy the test train requirements, which further proves the effectiveness of the proposed virtual prototype.
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Kristyawan, Yudi, and Muchammad Asro Rofi’i. "Early Detection of Overheating in Motorcycle Disc Brakes Based on Arduino." Inform : Jurnal Ilmiah Bidang Teknologi Informasi dan Komunikasi 6, no. 1 (January 31, 2021): 21–27. http://dx.doi.org/10.25139/inform.v6i1.3348.
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The braking system is very important on a motorcycle. The primary function of the braking system is to slow down and even stop the motorcycle. The braking system using disc brakes on motorcycles is commonly used today, especially on automatic transmission motorcycles. One of the disadvantages of disc brakes is the heat caused by the disc's friction with the brake pads if you apply continuous braking. This continuous braking is often done by a motor rider when crossing downhill roads in mountainous areas. Excessive heat in the disc brakes causes the brake fluid to boil, resulting in air bubbles resulting in braking failure. The failure of the braking system on a motorcycle is hazardous for the rider and others. The experimental method detects braking system failure by catching the disc brake's temperature with a touchless temperature sensor, MLX90614. Temperature detection is processed with Arduino as a control, and the temperature is displayed on the LCD. If the disc brake temperature is above 200oC, a buzzer is activated as a warning to the driver. The test results show that the system can display a temperature reading on the LCD lower than the thermometer gun, with the most inferior reading difference of 0.2oC and the highest 0.4oC. The system can also display notifications to users on disc brake temperatures above 200oC, namely at temperatures of 211.1oC, 224.3oC, and 237.5oC, which were achieved at 200, 225, and 250 seconds.
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Chi, Zhongzhe, Greg F. Naterer, and Yuping He. "EFFECTS OF BRAKE DISC GEOMETRICAL PARAMETERS AND CONFIGURATIONS ON AUTOMOTIVE BRAKING THERMAL PERFORMACE." Transactions of the Canadian Society for Mechanical Engineering 32, no. 2 (June 2008): 313–24. http://dx.doi.org/10.1139/tcsme-2008-0020.
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This paper examines the effects of geometrical parameters of pillar post rotors on the thermal performance of automotive vehicle brakes. The thermal performance of vented disc brakes strongly depends on the aerodynamic characteristics of the air flow through the rotor passages. These air flow passages are determined by the geometrical parameters of the brake rotors. In this study, different pillar post rotor models are considered and the corresponding numerical simulations are performed, in order to investigate the effects of various geometrical parameters on the thermal performance. These geometrical parameters include the shape, size, and distribution of a pillar post. The new insight from these parametric studies provides useful guidelines to optimize the geometry of pillar post rotors of automotive vehicles.
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MARIN, Florin-Bogdan, and Mihaela MARIN. "CFD Modeling of Aerodynamic Car Brake Cooling System." Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science 44, no. 4 (December 15, 2021): 44–47. http://dx.doi.org/10.35219/mms.2021.4.08.
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The objective of this experimental research is to identify solutions for an optimal cooling of the disks. The aerothermal brake cooling calculation is used to determine how the brake cooling process evolves. The techniques for simulating the dynamics of the CFD fluid allow us to simulate the cooling of the brakes in air current and then to compare the results obtained in the wind tunnel.
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Verbitskiy, V. V., and V. M. Pogosyan. "Compressor type engine brake." Traktory i sel'hozmashiny 1, no. 3 (2021): 27–30. http://dx.doi.org/10.31992/0321-4443-2021-3-27-30.
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The accident rate in road transport remains unacceptably high, and in order to reduce it, it is nec-essary to take into account all the factors affecting this process. In this regard, the process of long-term braking deserves special attention, which negative processes require the creation of additional braking systems (retarder brakes) for vehicles operating in mountainous areas, primarily in the field of passenger transportation. Transmission retarder brakes that provide sufficient braking performance have a number of dis-advantages that inhibit their use. Existing engine retarder brakes provide insufficient deceleration, and studies were carried out at the Kuban State Agrarian University (KubSAU) to improve their efficiency. After a theoretical analysis, the compressor brake mode was experimentally investigated. The in-creased pressure was created in the intake manifold and at the end of the compression stroke, air from the cylinder was released through a special valve back into the system, due to which the brak-ing effect was created. The carried out experiments confirmed the possibility of a significant increase in the engine braking torque in the compressor brake mode, when both valves are closed - the exhaust after the exhaust manifold and the intake in front of the carburetor, and compressed air is supplied to the in-take manifold at different pressures. Then the braking torque increases in comparison with engine braking by more than 3 times.
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Mullisen, R. S. "Thermal Engineering Design Project: Disk Brake Cooling Simulation." International Journal of Mechanical Engineering Education 25, no. 4 (October 1997): 299–305. http://dx.doi.org/10.1177/030641909702500406.
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A thermal engineering design project involving simulated cooling of vented and nonvented disk brakes is described. A heated copper tube was rotated in a manner that replicated the motion of a single vented passageway inside a disk brake rotor. The class assignment required design and construction of equipment, and data reduction using the lumped heat capacity method to obtain heat transfer correlations. The seven student groups plus the author produced 238 data points which were collectively correlated into two Nusselt number curves. The curve for the nonvented brakes simulation was benchmarked against the published literature for a cylinder in crossflow; the deviation was about 31%. The results from the vented brakes simulation which, in addition to the external air flow, had an internal radial flow driven by the rotation produced a 30% cooling augmentation over the nonvented simulation.
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Munisamy, Kannan M., Mohd Zamri Yusoff, and Savithry K. Thangaraju. "Ventilated Brake Disk Air Streamlining Using Curved Vane." Applied Mechanics and Materials 225 (November 2012): 26–31. http://dx.doi.org/10.4028/www.scientific.net/amm.225.26.
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The past research by the author on the conventional brake disk design i.e. straight blade bi-directional design, a misalignment of flow was identified. The misalignment was quantified using CFD as design tool. In the effort of re-aligning the flow angle helical lines fitted onto the conventional inner and outer diameter disk brakes yielded two different design innovation. The two “curved” designs have highlighted tremendous improvement on flow characteristics. Experimental analysis is carried out on the two curved 1 and curved 2 prototypes. The quantitative mass flow rate result is compared for conventional and the two curve shaped brake disk. Then, the data is fed as input condition to Computational Fluid Dynamics (CFD) model for disk brake models to analysis the flow characteristics qualitatively. The aerodynamics visualization through CFD supports well the mass flow improvement. The non-dimensional flow number is established and the correlation between flow number and Reynolds number is highlighted.
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B, Aboli, Waghmode ., and Dr S. N. Khan. "Design, Analysis and Shape Optimization Disc Brake by Using Thermal Analysis and Practical Testing." International Journal for Research in Applied Science and Engineering Technology 10, no. 7 (July 31, 2022): 1297–304. http://dx.doi.org/10.22214/ijraset.2022.45472.
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Abstract: The disc brake is a device for slowing or stopping the rotation of a wheel. Friction causes the disc and attached wheel to slow or stop. Brakes convert friction energy into heat energy and this heat will be transfer to the disc. By using disc heat is send to air. For sending heat to air disc having cut section and hole on surface to improve heat transfer. In this paper we work on to improve heat transfer to air by using shapes. We work on original disc brake and developed five new shape for analysis. When we do the thermal analysis we found that one disc having better result than original one. So we final this disc for manufacturing and we test both disc
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Cinq-Mars, Max, and Hakan Gurocak. "Pneumatic cylinder with magnetorheological brake using serpentine and helix flux guide as a linear hybrid actuator for haptics." Journal of Intelligent Material Systems and Structures 28, no. 10 (September 9, 2016): 1303–21. http://dx.doi.org/10.1177/1045389x16667562.
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This research explored a new linear hybrid actuator, which consists of a pneumatic cylinder with a magnetorheological brake embedded in its piston. Magnetorheological brakes are promising actuators since they can apply large forces in a small actuator size, but they can only oppose motion, as they are passive actuators. Pneumatic cylinders are desirable actuators due to their high force-to-weight ratio and ability to apply active forces. However, they require expensive servo valves for precise position control. The new hybrid actuator benefits from the advantages of magnetorheological brakes and pneumatic cylinders. It can apply forces using compressed air and can resist external forces using the magnetorheological brake. The embedded brake also eliminates the undesirable side effects of using compressed air and allows precise positioning of the piston anywhere in its stroke with simple solenoid valves. Fields such as haptics and robotics might benefit greatly from the use of the hybrid actuator where a high force-to-weight ratio could be employed. The study contributes (1) a triple helix flux guide for the linear magnetorheological brake, (2) serpentine flux path to enable larger braking forces, (3) shear mode activation, and (4) control algorithms that enable use of simple solenoid valves and improved power efficiency. When compared to an existing purely pneumatic control algorithm, the hybrid actuator exceeded the performance in position tracking and force disturbance rejection. A power management algorithm demonstrated that disabling the brake when the piston was in position vastly decreases the power consumption.
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García-León, R. A., N. Afanador-García, and J. A. Gómez-Camperos. "Numerical Study of Heat Transfer and Speed Air Flow on Performance of an Auto-Ventilated Disc Brake." Fluids 6, no. 4 (April 16, 2021): 160. http://dx.doi.org/10.3390/fluids6040160.
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In the braking system, the heat dissipation generated by the friction between the disc and pad should be evacuated as quickly as possible. In this work, five common different automotive disc brakes were studied through mathematical theories of heat transfer and numerical methods using the ANSYS software. In addition, a direct comparison between experimental, theoretical, and simulation values found in the open literature was performed to propose a disc brake with an improved geometry in terms of dissipation of heat transfer. The numerical results were considered to propose two possible solutions of disc brake geometries using N-38 ventilation blades used in aeronautic engineering. An improvement in temperature dissipation was achieved by approximately 23.8% compared to the five geometries analyzed with a simple type N-38 ventilation blade. The heat dissipation in the brakes strongly depends on the geometry of the disc, the geometry of the blades, the material from which it is manufactured, the material of the pad, the weight of the vehicle, and the operating conditions, as can be verified with mathematical calculations and experiments. The results obtained demonstrate that the discs can be used effectively in extreme working conditions (80 km/h and 33°C), without affecting the safety of the occupants and the braking system.
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Arasu, S., and A. Krishnamoorthy. "Design and Manufacturing of Conical Vent Profile Disc Brake." Applied Mechanics and Materials 766-767 (June 2015): 1028–33. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.1028.
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Braking system is one amongst the foremost vital contact mechanisms in an automobile. The braking potency in automobile depends on the desertion characteristics of the constraint assembly. The heat refusal from the system is proportional to the desertion of brake. This paper aims to bring out producing, testing of conical shape vent profile and studies of existing cooling vent profile heat refusal throughout the braking. This result reduces the thermal and structural stress on the brake plate. The prevailing vehicles brakes has been made from cylindrical vent profiles that in theory has lesser cooling potency because the direction of the air flow .The profile favor to increase the cooling potency by conical shape vent. The vent is reshaped in such some way that the face of the round shape vent is within the direction of air flow throughout vehicle motion that permits a lot of quantity of air to flow across the brake plate. This style changes results to extend the heat convey rate throughout the braking
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Jing, Zhecheng, and Ren He. "Electronic structural improvement and experimental verification of a tractor-semitrailer air brake system." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 8 (February 7, 2020): 2154–61. http://dx.doi.org/10.1177/0954407019899794.
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Brake time delay, which is a major shortcoming of air brake systems, may lead to precarious situations. In this study, the structure of an air brake system of a tractor–semitrailer was optimized by adding a shuttle valve and a two-position-three-port electromagnetic valve between the control pipeline and the charging pipeline downstream of the trailer control valve. The new electronically controlled structure clearly ensures that the semitrailer brakes faster, as validated by a simulation, bench test, and real-vehicle test. The simulation results reveal considerable improvements in the braking time, braking distance, longitudinal kinetic energy, lateral kinetic energy, and β phase plane. The bench test indicates that in the proposed structure, the average response time of service brake cylinders of the first and third axles of the semitrailer are 0.12 and 0.17 s, respectively. In addition, the real-vehicle test indicated that the service brake cylinders of the first and third axles responded 0.12 and 0.18 s earlier than those in the original system, respectively.
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Belhocine, Ali, and Wan Zaidi Wan-Omar. "CFD modeling and computation of convective heat coefficient transfer of automotive disc brake rotors -Modelado CFD y cálculo de la transferencia de coeficientes de calor por convección de rotores de freno de disco automotores." Revista Científica 2, no. 29 (May 1, 2017): 116. http://dx.doi.org/10.14483/udistrital.jour.rc.2017.29.a1.
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Braking system is one of the basic organs to control a car. For many years, the disc brakes have been used in automobiles for safe retardation of the vehicles. During braking, enormous amount of heat will be generated, and for effective braking, sufficient heat dissipation is essential. The specific air flow surrounding the brake rotor depends on the thermal performance of the disc brake and hence, the aerodynamics is an important in the region of brake components. A CFD analysis is carried out on the braking system as the study of this case, to make out the behaviour of air flow distribution around the disc brake components using ANSYS CFX software. The main object of this work is to calculate the heat transfer coefficient (h) of the full and ventilated brake discs as a function of time using the CDF analysis which will be used later in the transient thermal analysis of the disc in ANSYS Workbench 11.0.
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Cruceanu, Cătălin, Camil Ion Crăciun, and Ioan Cristian Cruceanu. "Effects of Mechanical Wheel Slide Protection Devices Action on Railway Vehicles Braking Process." Applied Mechanics and Materials 809-810 (November 2015): 1085–90. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.1085.
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The paper investigates the effects of mechanical wheel slide protection devices (WSPD) on the braking capacity for coaches equipped with disc or cast iron block brakes. Decelerations and jerks, that affect the passengers comfort, are also analyzed. An original simulation program, based on experimentally determined air pressure evolutions in brake cylinder is used for this purpose. Results of numerical simulations show that in the case of repeated actuations of mechanical WSPDs, disc brake vehicles are more affected in terms of braking capacity. Regarding jerks during braking actions, in both normal and low adhesion conditions, vehicles equipped with high power cast iron block brake with two pressure levels prove to be more affected.
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Švábenská, Eva, and Pavla Roupcová. "Hidden Hazard of Wear Particles." Chemické listy 116, no. 4 (April 15, 2022): 228–34. http://dx.doi.org/10.54779/chl20220228.
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Intensifying the mobility and the increase of the number of vehicles give rise to a larger amount of particles released by the brake abrasion. The particles, containing various elements and substances hazardous for some organisms, get subsequently into the air and the environment along busy roads. The aim of this review article is to provide information on both the composition of friction composites and transport-related emissions. The article is focused mainly on the wear particles released from brakes, but also on methods used to identify the source of the polluting particles are discussed.
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SHARIFULLIN, I. A., A. L. NOSKO, E. V. SAFRONOV, and D. V. KIRILLOV. "RESEARCH OF THE OPERATION OF MAGNETIC BRAKE ROLLERS OF GRAVITY ROLLER CONVEYORS." Fundamental and Applied Problems of Engineering and Technology, no. 4 (2021): 134–43. http://dx.doi.org/10.33979/2073-7408-2021-348-4-134-143.
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One of the main elements of safe operation of gravity conveyors used in gravity racks for pallets is the brake roller. The most promising design is a brake roller of magnetic (eddy current) type. A mathematical model of the process of moving pallets on a magnetic brake roller is developed. The equation of the speed of movement of the pallets on the brake magnetic roller obtained. The main parameter that determines the braking functions of the brake magnetic roller, and therefore the speed of movement of the pallet on the gravity roller conveyor is the coefficient of magnetic viscosity. A comparative experimental evaluation of the magnetic viscosity coefficient of eddy-current brakes of two designs - disk and centrifugal - has been carried out. It has been established that the coefficient of magnetic viscosity for both designs of brakes decreases with an increase in the air gap between the conductive body and the magnets when the magnets are placed on one and on both sides of the conductive body, and this dependence is exponential; for a disc brake, when magnets are placed on both sides of a conductive body, 2.5-3 times more than with a magnet located on one side of the disc; for a centrifugal brake when magnets are placed on both sides of a conducting body, 4-4.5 times less compared to a conducting body in the form of a disc with magnets on both sides and 1.5-2 times less than a conducting body in the form of a disc with a magnet one side.
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Subramanian, S. C., S. Darbha, and K. R. Rajagopal. "A Diagnostic System for Air Brakes in Commercial Vehicles." IEEE Transactions on Intelligent Transportation Systems 7, no. 3 (September 2006): 360–76. http://dx.doi.org/10.1109/tits.2006.880645.
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Bowlin, C. L., S. C. Subramanian, S. Darbha, and K. R. Rajagopal. "Pressure control scheme for air brakes in commercial vehicles." IEE Proceedings - Intelligent Transport Systems 153, no. 1 (2006): 21. http://dx.doi.org/10.1049/ip-its:20055007.
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Hardy, M. S. A., and D. Cebon. "An Investigation of Anti-Lock Braking Strategies for Heavy Goods Vehicles." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 209, no. 4 (October 1995): 263–71. http://dx.doi.org/10.1243/pime_proc_1995_209_213_02.
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An articulated lorry was instrumented in order to measure its performance in straight-line braking. The trailer was fitted with two interchangeable tandem axle sub-chassis, one with an air suspension and the other with a steel monoleaf four-spring suspension. The brakes were only applied to the trailer axles, which were fitted with anti-lock braking systems (ABS), with the brake torque controlled in response to anticipated locking of the leading axle of the tandem. The vehicle with the air suspension was observed to have significantly better braking performance than the steel suspension, and to generate smaller inter-axle load transfer and smaller vertical dynamic tyre forces. Computer models of the two suspensions were developed, including their brakes and anti-lock systems. The models were found to reproduce most of the important features of the experimental results. It was concluded that the poor braking performance of the steel four-spring suspension was mainly due to interaction between the ABS and inter-axle load transfer effects. The effect of road roughness was investigated and it was found that vehicle stopping distances can increase significantly with increasing road roughness Two alternative anti-lock braking control strategies were simulated. It was found that independent sensing and actuation of the ABS system on each wheel greatly reduced the difference in stopping distances between the air and steel suspensions. A control strategy based on limiting wheel slip was least susceptible to the effects of road roughness
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Rosenow, Judith, Thomas Sachwitz, Shumpei Kamo, Gong Chen, and Hartmut Fricke. "Aircraft-Type-Specific Impact of Speed Brakes on Lift and Drag." Aerospace 9, no. 5 (May 12, 2022): 263. http://dx.doi.org/10.3390/aerospace9050263.
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The increasing influence of current research in air traffic management on daily flight operations leads to a stronger consideration of individually optimized aircraft trajectories. However, in the dichotomy between ecological, economic, and safety-based optimization goals, four-dimensionally optimized trajectories are subject to severe constraints in terms of position and speed. To fully assess the performance envelope of these trajectories, precise modelling of the influence of secondary control surfaces on flight performance is necessary. In particular, the use of speed brakes can significantly influence the descent and speed profile and allows the implementation of different cost indices. In this study, we present a modelling approach of the influence of extended speed brakes on flight performance and apply this method in a simulation environment for trajectory modelling of twelve different aircraft types. In doing so, we can determine an almost linear influence of the additional fuel requirement from the effective area of the speed brakes. The results can be implemented in any flight performance model and enable more precise modelling of future aircraft trajectories. Specifically, optimization targets regarding the required time of arrival, or the cost index and the consideration of the dynamic impact of atmospheric conditions in the trajectory optimization, only becomes possible through the calculation of the influence of the speed brake on lift and drag.
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Perricone, Guido, Mattia Alemani, Ibrahim Metinöz, Vlastimil Matějka, Jens Wahlström, and Ulf Olofsson. "Towards the ranking of airborne particle emissions from car brakes – a system approach." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 231, no. 6 (August 24, 2016): 781–97. http://dx.doi.org/10.1177/0954407016662800.
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Airborne particulate matter emitted from motor vehicle brakes is a contributor to urban air quality. Therefore, a method to rank brake pairs (pads and rotors) with respect to their particle emission factors in a reliable way is needed to develop a low-emission disc brake. A novel inertial disc brake dynamometer designed for brake particle emission studies, a modified SAE J 2707 cycle, an electrical low-pressure cascade impactor and a filter are used to test five different pad materials against cast-iron rotors. By changing only the pad materials, it is shown that the differences between the mass emission factor and the number emission factor of the the worst brake pair and those of the best brake pair decreases by more than four times and 19 times respectively. Furthermore, the results show that the material combination ranked the best in terms of the mass emission factor is ranked the worst in terms of the number emission factor. The results reveal that this combination of a test stand, a test cycle and particle instruments can discriminate between different brake pair materials in a reliable way in the case of the mass emission factors while more research has to be carried out in the case of the number emission factors.
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Subel, Joshua, and Frank W. Kienhöfer. "Thermal comparison of heavy vehicle wheel assemblies under alpine braking." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 1 (May 3, 2019): 28–38. http://dx.doi.org/10.1177/0954407019844359.
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Overheating brakes cause brake fade, tyre blowouts and vehicle fires, but no study has investigated the influence of wheel configuration or rim material on these catastrophic failures. Laboratory measurements of the transient thermal response of heavy vehicle wheel assemblies to [Formula: see text] of alpine friction braking are presented; comparing brake and tyre temperature when using dual and single wheels with steel and aluminium rims. Under an averaged braking power of [Formula: see text], the final temperature increase of the brake was [Formula: see text] (3.7%) higher when using steel versus aluminium rims. The final increase in maximum tyre temperature was [Formula: see text] (16%) higher when using aluminium versus steel rims and [Formula: see text] (76%) higher when using single versus dual wheels. The greater thermal conductivity and cross-sectional area of the aluminium rims relative to the steel rims reduce the thermal resistance of braking heat flowing into the tyre; leading to higher tyre temperature when using aluminium rims. Dual rims and tyres have larger surface areas than singles which convect more heat to the air at lower temperatures; leading to cooler tyres when using dual wheels. The higher thermal diffusivity of aluminium and lower thermal capacities of single wheels also cause tyre temperature to rise more rapidly than when using steel rims or dual wheels. These results indicate that the risk of tyres overheating (which could lead to blowout) from extended use of the brakes is increased when using single wheels compared to dual wheels and further exacerbated by using aluminium rims compared to steel rims.
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Zhao, Fang, Mu Yi Lin, and Zhun Wang. "On Hydraulic Brake System Using Bench Experiments for Off-Road Vehicles." Advanced Materials Research 588-589 (November 2012): 327–30. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.327.
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The full power hydraulic brake system has several advantages over traditional brake actuation systems. These systems are capable of supplying fluid to a range of very small and large volume service brakes with actuation that is faster than air/hydraulic brake systems. Implementation of full power hydraulic brake system in off-road vehicles calls for good understanding of its dynamic characteristics. In this paper, we consider the problem of dynamic modeling of the brake system and develop a dynamic model for a hydraulic brake valve. First, the dynamic characteristics of full power hydraulic brake system are analyzed theoretically. The effects of varying design parameters (brake valve, accumulator and so on) and the different operating conditions are then analyzed. Second, we investigate the dynamic characteristics of a full power hydraulic brake system using a test bench, which is a loader brake system specifically designed for one construction Machinery Company. Finally, based on the experimental results, the mathematical models are amended and verified. The result shows that the model-calculated data agree well with tested data. The dynamic behavior of hydraulic valve can be well predicted with the model. The simplified models can be applied to the studies of full power hydraulic brake system dynamics.
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Ridane, N., D. Jaksic, Matthias Kleiner, and B. Heller. "Enhanced Semi-Analytical Process Simulation of Air Bending." Advanced Materials Research 6-8 (May 2005): 729–36. http://dx.doi.org/10.4028/www.scientific.net/amr.6-8.729.
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The air bending process is one of the most widely used process for the manufacturing of sheet metal bending parts made of thin as well as of thick sheet metal. Although the air bending process offers a very high production potential due to its great flexibility, it is associated with certain problems which can negatively influence the shape and dimensional accuracy of the bending parts. Examples for such negative influences are the springback of the material, the batch variations, or the deflections of the bending machine and tools. These differences have to be considered either in the determination of the process parameters or they have to be compensated later on in the manufacturing process itself. A well established approach to calculate process data for forming processes is the use of a process simulation. At the Institute of Forming Technology and Lightweight Construction (IUL) a simulation software called Sheet Metal Bending Simulation (SMBS) has been developed and successfully been tested for the field of sheet metal bending, based on semi-analytical approaches. Although it already provides very satisfactory results in general, disturbances such as material and batch variations as well as the deflections of C-frame, machine table, and press brake ram can still negatively affect the prediction of the punch displacement necessary to achieve a certain bend angle. While material and batch variations cannot properly be considered in a process simulation at present, the afore mentioned influences offer a promising potential for improvements. Therefore, in order to further improve the accuracy of predicted quantities such as punch displacement and bending angle, a new module describing the elastic machine behaviour of press brakes has been developed and successfully been integrated in the process simulation SMBS. Experimental investigations have been carried out on a conventional CNC press brake to verify the efficiency of the newly implemented approach.
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Barta, Dalibor, Jana Gallikova, and Jacek Caban. "Maintenance system of semi-trailer and risk priority number." Archives of Automotive Engineering – Archiwum Motoryzacji 86, no. 4 (December 23, 2019): 101–9. http://dx.doi.org/10.14669/am.vol86.art7.
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The new maintenance system of semi-trailer combination as a most used road freight transport means is the subject of interest in this article. The real experiences from practice and creation of the FMEA analysis of the system using software support are the basis of wear and damage analysis of air brake system components used on the semi-trailer combination. The desire to improve market position of the company, customer satisfaction, but also the product specifications, government regulatory requirements, agency recommendations, and legal implications are the grounds for continuous improvement of the product quality, reliability and safety. These reasons push the product manufacturers to perform risk analyses, which helps them identify and minimize system failures during the life cycle of product. One of the risk analysis techniques recommended by international standards to identify possible failure causes is the FMEA methodology. It helps to locate the failures and reduce their consequences, so that the intended function of the machine is fulfilled. In this paper was presented the wear and damage analysis of individual components of air brake system and creating of the FMECA analysis for semi-trailer combination. Base on them, new methods to detect failures of components of air systems, preventive measures and set up of a new planned preventive maintenance system for air brakes was designed. The cost of the proposed maintenance system is 2.2 times higher than the cost of the current maintenance system, but it minimizes the failures and their consequences (traffic accidents).
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Aboubakr, Ahmed K., Martino Volpi, Ahmed A. Shabana, Federico Cheli, and Stefano Melzi. "Implementation of electronically controlled pneumatic brake formulation in longitudinal train dynamics algorithms." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 230, no. 4 (November 9, 2016): 505–26. http://dx.doi.org/10.1177/1464419316628764.
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The main goal of this investigation is to integrate an electronically controlled pneumatic (ECP) brake model with efficient longitudinal train force algorithms based on the trajectory coordinate formulations. The ECP brake model, developed in this investigation consists of the train line (cable), locomotive automatic brake valve, air brake pipe, and ECP manifold. The train line, which covers the entire length of the train, allows the brake commands to be received by the car simultaneously. While pneumatic pressure is used to generate the braking forces, the brake pipe is no longer used to provide the brake level commands. Instead, the brake pipes are used to provide a continuous supply of compressed air stored in a reservoir mounted on each railcar. Using the ECP system to apply the brakes uniformly and instantaneously gives better train control, shortens the stopping distances, and leads to a lower risk of derailment. In this investigation, the fluid continuity and momentum equations are used to develop the governing air pressure flow equations. These partial differential equations are converted to a set of ordinary differential equations using the finite element method leading to an air brake force model that accounts for the effect of the air flow in long train pipes as well as the effect of leakage and branch pipe flows. The car brake forces are applied to the wheels using the ECP manifold located in each car. The ECP manifold used in this investigation has four valves: cut-off valve, vent valve, auxiliary valve, and emergency valve. The ECP manifold is connected to three main pneumatic components: the auxiliary reservoir, the emergency reservoir, and the brake cylinder. The reservoirs serve as the main storage of the pressurized air, while the brake cylinder and other mechanical components such as the rigging and the brake shoes transmit the brake force to the wheels. In this investigation, a mathematical model of the ECP manifold and its components is developed. The relationship between the main components of the ECP brake system and the train dynamics is discussed, and the final set of differential equations that integrates the ECP brake and train dynamics is presented. Different simulation scenarios are considered in this study in order to investigate the effect of the brake forces on the train longitudinal dynamics in the case of different braking scenarios. The performance of the developed ECP brake system is compared with the Association of American Railroads safety and operation standards, and with experimental results published in the literature.
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Kosmač, Tomaž, Aleš Dakskobler, Mihael Kermc, and Zmago Stadler. "Ceramic Piston for Hydraulic Brakes: Design Study." Advances in Science and Technology 45 (October 2006): 1771–75. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1771.
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A design study for ceramic pistons was undertaken in order to address the overheating problems associated with the caliper during aggressive braking using modern C/C-SiC brake discs. The reasoning behind the piston design and the choice of the shaping technology are explained. Zirconia-toughened mullite (ZTM) ceramic was chosen for the pistons, because this material exhibits a low thermal conductivity, sufficiently high mechanical strength and fracture toughness, as well as very good thermal-shock resistance. The manufacturing technology of experimental ceramic brake pistons involved compounding of the selected starting powders to form a high-solids-loadingcontaining feedstock, tooling, shaping of green parts by low-pressure injection molding, extraction of the organic binder, pressure-less sintering in air and final machining. Prototypes brake pistons were fabricated and successfully tested as components of motorcycle brake systems in a test laboratory and on a motorcycle racing track.
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Duflou, Joost R., Hans Vanhove, and Willem de Coninck. "Adjustable Tooling System for Air Bending." Key Engineering Materials 549 (April 2013): 270–76. http://dx.doi.org/10.4028/www.scientific.net/kem.549.270.
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The productivity of bending on press brakes is strongly affected by the changeover time between consecutive tooling setups. The need for flexible tooling systems that can reduce the setup time is therefore obvious. This isa fortioritrue for robot supported bending operations, where the tool system should preferably allow fully automated setup of bending stations. In this article an innovative tooling system concept is presented that can adjust to different punch profiles (from straight tools to deep gooseneck profiles), provide horn tool functionality and allow setups with open punches for collision avoidance during bending. The Leuven bend tooling design can accommodate fully automated changeover between bending jobs. A prototype version of the Leuven bending tool system has been manufactured and extensively tested. Validation results with respect to achievable load levels and stiffness are reported in the article.
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Talib, Irsa, Jawad Hussain, Imran Amjad, Muhammad Fahad Abid, Dawood Sajjad, Mifrah Ali, and Fizza Ghulam Nabi. "Brake Power and Load Analysis of Electromagnetic Braking System." Pakistan Journal of Engineering and Technology 5, no. 2 (September 12, 2022): 140–45. http://dx.doi.org/10.51846/vol5iss2pp140-145.
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This study aimed to develop a model and prototype of a more sustainable electromagnetic braking system which can cope with the future demands of the automobile industry due to the increasing number of e-vehicles. The braking mechanism is been used in almost every type of mechanical vehicle and it utilizes crude oil as fuel which when burnt causes air pollution. To save the environment from air pollution e-vehicles have been introduced to the market. Electromagnetic brakes are been used in e-vehicles as these vehicles incorporate huge electric systems which may be damaged or ignited through any leakage from the hydraulic brake. In this study, engineering knowledge has been implemented to design and fabricate a model of the electromagnetic braking system (EMS) which works on the principle of eddy current. A 3D model of EMS was developed. Further, static displacement and brake power analyses were performed to check the strength of EMS and the performance of the prototype developed, respectively. At an average speed of 31 RPM, brake power produced was 3.9 W. Static structural analysis on a frame made of grey cast iron showed that there was negligible deformation for load up to 200 N. Electromagnetic braking system based on this analysis and model could meet the market needs for conveyor belt application as well. The observations from this study might be useful in the development of a more efficient electrical vehicle braking system with varying demands of momentum.
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Wang, Qihang, Tianci Gao, Haichuan Tang, Yifeng Wang, Zhengxing Chen, Jianhui Wang, Ping Wang, and Qing He. "A feature engineering framework for online fault diagnosis of freight train air brakes." Measurement 182 (September 2021): 109672. http://dx.doi.org/10.1016/j.measurement.2021.109672.
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Jadhav, Rohit. "Design and Optimization of Wheels for Better Aerodynamics and Cooling of Brakes." International Journal for Research in Applied Science and Engineering Technology 10, no. 12 (January 31, 2022): 418–40. http://dx.doi.org/10.22214/ijraset.2022.39853.
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Abstract: In the world of automotive, lots of research has been done yet on overall vehicle. Researchers improved every single part of vehicle but wheel is one of the part that hasn’t changed much in automotive history. In case researchers got their desired results, they stopped working on wheel and most of the research has been done on grip of the tire. That’s why there is no innovative research done on wheels. And it is one the biggest part who contribute in vehicles performance and other aspects like comfort and ride quality. Most of the manufacturers never consider and work on aerodynamic part of wheel. So, Different aerodynamics concept vehicles have been studied in the report. The flow around wheels are manage and smoothen in proposed design also it is designed in such a way that air flowing around wheel can easily take inside through Rim design and throw on brake pads as well as on wheel hub for consistently cooling them. They key for success is to manage the flow and keep the wheel functional and attractive. In this paper new wheel is designed and compared with convectional wheel designs. Keywords: Wheel Aerodynamics, Design and Optimization of Wheel, Cooling of Brakes, 3D Wheel design, Aerodynamics of Wheel.
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Rahimi, Mostafa, Daniele Bortoluzzi, and Jens Wahlström. "Input Parameters for Airborne Brake Wear Emission Simulations: A Comprehensive Review." Atmosphere 12, no. 7 (July 4, 2021): 871. http://dx.doi.org/10.3390/atmos12070871.
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Non-exhaust emissions, generated by the wear of brake systems, tires, roads, clutches, and road resuspension, are responsible for a large part of airborne pollutants in urban areas. Brake wear accounts for 55% of non-exhaust emissions and significantly contributes to urban health diseases related to air pollution. A major part of the studies reported in the scientific literature are focused on experimental methods to sample and characterize brake wear particles in a reliable, representative, and repeatable way. In this framework, simulation is an important tool, which makes it possible to give interpretations of the experimental results, formulate new testing approaches, and predict the emission produced by brakes. The present comprehensive literature review aims to introduce the state of the art of the research on the different aspects of airborne wear debris resulting from brake systems which can be used as inputs in future simulation models. In this review, previous studies focusing on airborne emissions produced by brake systems are investigated in three main categories: the subsystem level, system level, and environmental level. As well as all the information provided in the literature, the simulation methodologies are also investigated at all levels. It can be concluded from the present review study that various factors, such as the uncertainty and repeatability of the brake wear experiments, distinguish the results of the subsystem and system levels. This gap should be taken into account in the development of future experimental and simulation methods for the investigation of airborne brake wear emissions.
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Wahlström, Jens, Mara Leonardi, Minghui Tu, Yezhe Lyu, Guido Perricone, Stefano Gialanella, and Ulf Olofsson. "A Study of the Effect of Brake Pad Scorching on Tribology and Airborne Particle Emissions." Atmosphere 11, no. 5 (May 10, 2020): 488. http://dx.doi.org/10.3390/atmos11050488.
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Non-exhaust wear emissions from disc brakes affect the air quality in cities throughout the world. These emissions come from the wear of the contact surfaces of both the pads and disc. The tribological and emissions performance of disc brakes strongly depend on the contact surface characteristics of the pads and discs. The surfaces of conventional pads are scorched by heating it to several hundred degrees to make the resin carbonize down to a few millimetres deep into the pad. This is done to have a shorter run-in period for new pads. It is not known how scorching will affect the amount of airborne particle emissions. Therefore, the aim of the present study is to investigate how pad scorching influence the airborne particle emissions. This is done by comparing the pin-on-disc tribometer and inertia dyno bench emission results from a Cu-free friction material run against a grey cast iron disc. Three types of modified friction material surfaces have been tested: scorched, extra-scorched and rectified. The results show that the level of scorching strongly affects the airborne particle emissions in the initial phase of the tests. Even if the scorched layer is removed (rectified) before testing, it seems like it still has a measurable influence on the airborne particle emissions. The results from the tribometer tests are qualitatively in line with the inertia dyno bench test for about the first forty brake events; thereafter, the airborne particle emissions are higher for the scorched pads. It can be concluded that it seems that the level of scorching has an adverse influence on both the tribological performance and level of particle emissions.
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Vasiljević, Saša, Jasna Glišović, Jovanka Lukić, Nadica Stojanović, and Ivan Grujić. "Analysis of braking parameters in testing of brake wear and particles formation on inertial brake dynamometer." Tehnika 77, no. 2 (2022): 195–202. http://dx.doi.org/10.5937/tehnika2202195v.
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In parallel with the significant reduction of the impact of vehicles on the environment, the development of modern propulsion systems that have less and less harmful impact, new pollutants are being identified on the vehicle. One of the such pollutants is the brakes, which wear out and lead to the formation of particles that are released into the air, i.e. generally into the environment. Investigation of the mechanism of particle formation during braking, and thus the brake wear is today becoming one of the important areas of research. The most common tests in this area are performed using initial brake dynamometers and pin-on-disc machines. An overview of the influence of some operation parameters (initial vehicle speed, braking pressure, and deceleration) that varies frequently during testing on an inertial brake dynamometer is performed in this paper. There are a number of tests and cycles that are applied during research, but they are not specifically prescribed for testing the particle formation during braking. The UNECE (United Nations Economic Commission for Europe) has included it in its plan and is in the development phase of introducing standardized cycles that will prescribe the braking cycle, the purpose of which will be to examine the formation of particles. This kind of review paper can be important for researchers who are engaged in this field, and the develop their own cycles or tests to examine the concentration or mass of particles formed during braking.
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Cruceanu, Cătălin, and Camil Ion Crăciun. "Effects of Slow-Acting Brakes Application Time Regulated Limits on Freight In-Train Forces." Applied Mechanics and Materials 809-810 (November 2015): 1133–38. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.1133.
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The paper originally investigates the influence of the admitted ranges of slow-acting filling time of brake cylinder on longitudinal dynamics of freight trains, using experimental air pressure data obtained in tests on filling characteristics. Mechanical and pneumatic models are summarized and numerical simulations were performed for a train composed of six wagon train, in different filling characteristics configurations. The results reflect significant effects on in-train forces values, while evolution and disposition of compression and tensile forces between neighbored vehicles in the long of the train are also affected.
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Bian, Guangyu, and Houzheng Wu. "Friction performance of carbon/silicon carbide ceramic composite brakes in ambient air and water spray environment." Tribology International 92 (December 2015): 1–11. http://dx.doi.org/10.1016/j.triboint.2015.05.023.
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Wager, Guido, Jonathan Whale, and Thomas Braunl. "Performance evaluation of regenerative braking systems." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 10 (November 17, 2017): 1414–27. http://dx.doi.org/10.1177/0954407017728651.
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This research evaluates the energy gain from a regenerative braking system (RBS) in a commercial electric vehicle (EV), the OEM Mitsubishi i-MiEV. Measurements were conducted in a controlled environment on a commercial chassis dynamometer using international drive cycle standards. The energy recovery of the vehicle was modelled and the output of the model was compared with results from the chassis dynamometer driving. The experiments were original as they coupled changes in energy recovered and driving range due to the RBS settings with investigations into the time of use of the friction brake. Performance tests used two different drive cycle speed profiles and various RBS settings to compare energy recovery performance for a broad range of driving styles. The results show that due to reduced energy consumption, the RBS increased the driving range by 11–22% depending on RBS settings and the drive cycle settings on the dynamometer. The results further showed that driving an EV with a RBS uses the friction brakes more efficiently, which will reduce brake pad wear. This has the potential to improve air quality due to reduced brake pad dust and reduces the maintenance costs of the vehicle. The findings were significant since they showed that friction time of use, a parameter neglected in RBS testing, plays an important part in the efficient operation of an EV. The overall results from the vehicle energy recovery modelling showed good agreement with the data from drive cycle testing and the model has potential to be further developed to gain greater insight into vehicle RBS braking behaviour for EVs in general.
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Safronov, О. М., A. O. Sulim, Yu Ya Vodiannikov, and O. G. Маkeieva. "HIGH SPEED FREIGHT TRAIN FOR TRANSPORTATION OF CONTAINERS AT SPEED OF 200 KM/H." Railbound Rolling Stock, no. 22 (2021): 70–84. http://dx.doi.org/10.47675/2304-6309-2021-22-70-84.
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The article is devoted to building of freight trains for transportation of containers with railway transport at speed of 200 km/h. The article considers building experience of the high speed freight trains for transportation of containers at speed of 350 km/h. Main technical characteristics of the rolling stock, involved in freight high speed railway transportation in foreign countries are analyzed. The purpose of the article is to discover design features of the rolling stock for freight transportations at speed of 200 km/h and in modeling of the braking processes during electro pneumatic and pneumatic braking of the rolling stock from speed of 200 km/h to 160 km/h. The concept of the rolling stock for high speed freight transportation of containers is proposed. A specialized platform with bogies, disc brake and air-spring suspension Installed on it is used as a rolling stock. A brief description of the brake system is given; its main features are shown. A pneumatic scheme of the container block of the braking equipment and the general view of container block is given. Classified freight train, which consists of 30 platform cars and has two locomotives on each side is proposed for high speed transportation. Brake distance during electro pneumatic and pneumatic braking at freight train speed of 160 km/h is calculated. The results of calculated studies of the trains braking efficiency are given, which showed that at the speed of the freight train of 200 km/h, the brake distances at electro pneumatic and pneumatic braking are represented by 1472 m and 1571 m respectively, which corresponds to the technical requirements of the European Union TSI. Key words: high-speed freight trains, container, speed, brake distance, disc brakes.
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Wei, Wei, Yong Jiang, Yuan Zhang, Xubao Zhao, and Jun Zhang. "Study on a segmented electro-pneumatic braking system for heavy-haul trains." Transportation Safety and Environment 2, no. 3 (July 3, 2020): 216–25. http://dx.doi.org/10.1093/tse/tdaa015.
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Abstract The large longitudinal impact of heavy-haul trains is the main factor limiting their development, and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact. In this paper, a segmented electro-pneumatic braking solution fully compatible with the existing freight-train braking system in China is proposed to improve the synchrony of train-braking systems. A simulation model for this braking system is developed based on air-flow theory, the 120 distribution valve and electronic control devices. The braking characteristics obtained from simulations are compared to those from the train-brake testing platform, and show high fidelity. On this basis, the effects of the new braking system on the braking capacity and longitudinal impact of a 20 000 t heavy-haul train are analysed by further simulation. The results show that during service brakes, the segmented electro-pneumatic braking system can increase the braking capacity by 4.2–24.7% and reduce the coupler force by 21.6–68.0%. Therefore, it can be seen that the segmented electro-pneumatic braking system is a new type of electro-pneumatic brake that meets the needs of the Chinese railway network. It solves the problem of the longitudinal impact of heavy-haul trains satisfactorily, and its compatibility with the existing braking system (resulting in a reduced modification workload) makes it possible to maintain normal operations on heavy-haul lines while trains undergo modification.
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Zhang, Weiji, Han Zhao, Ang Zhao, Jiaqiao Lin, and Rui Zhou. "Current Status, Challenges and Resilient Response to Air Pollution in Urban Subway." Atmosphere 10, no. 8 (August 16, 2019): 472. http://dx.doi.org/10.3390/atmos10080472.
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Subway air pollution mainly refers to inhalable particulate matter (PM) pollution, organic pollution, and microbial pollution. Based on the investigation and calculation of the existing researches, this paper summarizes the sources of air pollutants, chemical compositions, and driving factors of PM variations in subway. It evaluates the toxicity and health risks of pollutants. In this paper, the problems and challenges during the deployment of air pollution governance are discussed. Results show that the global PM compliance rate of subway is about 30%. Subway air pollution is endogenous, which means that pollutants mainly come from mechanical wear and building materials erosions. Particles are mainly metal particles, black carbon, and floating dust. The health risks of some chemical elements in the subway have reached critical levels. The variations of PM concentrations show spatial-temporal characteristics, which are mainly controlled by train age, brakes types, and environmental control systems. The authors then analyze the dynamics of interactions among government, companies and public during the air pollution governance by adding the following questions: (a) who pays the bill; (b) how to evaluate the cost-effectiveness of policies; (c) how the public moves from risk perception to actions; (d) how to develop clean air technology better so as to ultimately incentivize stakeholders and to facilitate the implementation of subway clean air programme in a resilient mode.
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Tucholski, Zbigniew. "Wydawnictwa Techniczne Ministerstwa Komunikacji (1934–1939; 1946–1948)." Z Badań nad Książką i Księgozbiorami Historycznymi 5 (September 15, 2020): 273–94. http://dx.doi.org/10.33077/uw.25448730.zbkh.2011.279.
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The article deals with the beginnings of the Polish railway technological literature during the interwar period. It discusses the historical and typographical issues of the series entitled Wydawnictwa Techniczne Ministerstwa Komunikacji (The Technical Publications of the Ministry of Communication), opened in 1935, by the monograph Hamulce kolejowe (Railway Brakes) by eng. Mieczysław Zabłocki. During the years 1935–1939, there appeared twenty volumes in the series. Most of them were related to the technological issues of railway construction and development, although one dealt with air transportation, and one with installing and operating cable car lines (aerial tramways). World War II brought an abrupt end to the publishing of the series, but it was revived with the second edition of Zabłocki’smonograph of railway braeks in 1946. Through 1948 twelve volumes were published; once again chiefly concerned with railway technology. The only exception was the collective publication edited by eng. Tadeusz Tillinger entitled Drogi wodne (The Waterways). Both during the interwar period and after the Second World War, the volumes comprising the series Technical Publications of the Ministry of Communication were an important source of specialized information for railway employees in Poland. The work on the series within the Ministry of Communication also stimulated publishing activities of the appropriate ministerial departments.
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Ba Zuhair, Mohammed. "BALANCING AN AIRCRAFT WITH SYMMETRICALLY DEFLECTED SPLIT ELEVATOR AND RUDDER DURING SHORT LANDING RUN." Aviation 23, no. 1 (May 23, 2019): 23–30. http://dx.doi.org/10.3846/aviation.2019.10301.
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This article investigates methods for balancing aircraft during short straight-line landing run realized by employing split rudder and elevator as air-brakes after touchdown. For standard atmospheric and runway conditions, directional and longitudinal balance equations for aircraft of conventional configuration such as Il-86 are presented. Methods depend on operational and mechanical approaches, where the first requires manual or automatic trim of shortly peaking small pitching, yawing, and rolling moments using dynamic forces while the second suggest some re-design of elevator and rudder control channels to limit deflection angles. The paper describes in detail each method disadvantages and suggests the adoption of automatic operational approach due to less required system modifications and piloting skills.
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Grigoratos, Theodoros, Carlos Agudelo, Jaroslaw Grochowicz, Sebastian Gramstat, Matt Robere, Guido Perricone, Agusti Sin, et al. "Statistical Assessment and Temperature Study from the Interlaboratory Application of the WLTP–Brake Cycle." Atmosphere 11, no. 12 (December 2, 2020): 1309. http://dx.doi.org/10.3390/atmos11121309.
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The relative contribution of brake emissions to traffic-induced ambient Particulate Matter (PM) concentrations has increased over the last decade. Nowadays, vehicles’ brakes are recognised as an important source of non-exhaust emissions. Up to now, no standardised method for measuring brake particle emissions exists. For that reason, the Particle Measurement Programme (PMP) group has been working on the development of a commonly accepted method for sampling and measuring brake particle emissions. The applied braking cycle is an integral part of the overall methodology. In this article, we present the results of an interlaboratory study exploring the capacity of existing dynamometer setups to accurately execute the novel Worldwide Harmonised Light-Duty Vehicles Test Procedure (WLTP)–brake cycle. The measurements took place at eight locations in Europe and the United States. Having several dynamometers available enabled the coordination and execution of the intended exercise, to determine the sources of variability and provide recommendations for the correct application of the WLTP–brake cycle on the dyno. A systematic testing schedule was applied, followed by a thorough statistical analysis of the essential parameters according to the ISO 5725 standards series. The application of different control programmes influenced the correct replication of the cycle. Speed control turned out to be more accurate and precise than deceleration control. A crucial output of this interlaboratory study was the quantification of standard deviations for repeatability (between repeats), sample effect (between tests), laboratory effect (between facilities), and total reproducibility. Three critical aspects of the statistical analysis were: (i) The use of methods for heterogeneous materials; (ii) robust algorithms to reduce the artificial increase in variability from values with significant deviation from the normal distribution; and (iii) the reliance on the graphical representation of results for ease of understanding. Even if the study of brake emissions remained out of the scope of the current exercise, useful conclusions are drawn from the analysis of the temperature profile of the WLTP–brake cycle. Urban braking events are generally correlated to lower disc temperature. Other parameters affecting the brake temperature profile include the correct application of soak times, the temperature measurement method, the proper conditioning of incoming cooling air and the adjustment of the cooling airspeed.
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D'Urso, Gianluca, Giuseppe Pellegrini, and Giancarlo Maccarini. "The Effect of Sheet and Material Properties on Springback in Air Bending." Key Engineering Materials 344 (July 2007): 277–84. http://dx.doi.org/10.4028/www.scientific.net/kem.344.277.
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Angle control in air bending is achieved either by exploiting direct angle measurement (adaptive forming) or by controlling punch displacement. In general, the desired angle is supplied as input to CNC press brakes and the choice of punch stroke relies on either analytical or empirical models. Process geometry and material properties affect the outcome, therefore, full knowledge of these values is critical. Since a major source of inaccuracies is due to errors in material description (sheet thickness is critical as well), material data (or, more generally, sheet behavior information) collection in process is advisable. In air bending, process control can be improved by studying the total load as a function of punch displacement. This approach becomes more and more interesting since devices for load measurement are now available on the market. The aim of this work is to analyze some experimental load measures, collected in actual working conditions, to evaluate the accuracy of such technique and its potential for in process applications. Several sheet materials (ferrous and non-ferrous alloys) are studied through both bending and tensile tests; the resulting material properties (tensile and bending) are evaluated and compared. After data treatment of punch force signal, the ability of predicting punch displacement needed to reach a defined bending angle (after springback) is discussed.
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Jabłońska, Joanna. "The role of acoustics in building clean urban and architectural environment." BUILDER 276, no. 7 (June 24, 2020): 44–46. http://dx.doi.org/10.5604/01.3001.0014.1602.
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Built environment of polish cities, both external and internal is polluted not only with chemical and physical harmful particles, but also with a number of diversified, continuous sounds, which may in substantial way negatively affect psychological and physical well-being of humans. Moreover, in extreme situations sound may damage vital organs of organisms and at daily occasions negative exposure may cause a number of problems in a longer time perspective. Noise produced by traffic, loudness of school brakes, shouts and car-horns, humming of air condition devices and ducts, air traffic, plus many more, are exposing city users not only on shorter or longer hearing losses, but also on vibration of internal organs and raising of overall anxiety. At the same time, cities are also filled with positive sounds, which allow to lower the blood pressure, calm and relax residents, like: birds singing, leaves and rain humming, water floating, and so on. Hence, this article was devoted towards presentation of research outcomes on pursuit for ‘cleaner’ and higher quality of sound environment in everyday city, in order to create safer and more ergonomic permanent, day-to-day living conditions.
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Tongyu, Shi, and Wang Dazhi. "3D Analytical model of drag and lift force for a conductive plate moving above a Halbach magnet array." Transactions of the Institute of Measurement and Control 40, no. 12 (September 28, 2017): 3515–24. http://dx.doi.org/10.1177/0142331217724220.
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When a conductive plate moves above a Halbach magnetic source, a magnetic field will be created in the air gap. This field induces eddy currents in the plate and creates drag and lift forces simultaneously. This phenomenon may be applied into eddy current brakes, couplings or magnetic levitation systems. In this paper, by utilizing the derived analytical field solutions of the Maxwell equations with magnetic scalar potential and magnetic field strength, the 3D lift and drag forces, and the flux density distribution in the air gap are predicted and analysed in the steady-state condition. Calculation results produced by analytical model are compared with those from the 3D finite element method. A prototype of the disk-type permanent magnetic eddy-current coupling has been manufactured to validate the accuracy of the 3D analytical model. The results confirm that, compared with 2D analytical model from the papers that had already published, the results calculated by the 3D analytical model have a higher accuracy in performance analysis. Finally, the characteristics of different kinds of magnet arrays are compared based on the proposed model, and several main problems are analysed and discussed.
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Kodavanla, Babitha, Dr A. Barai, A. B. S. Dadapeer, Mery Threza, P. Hanuma, and N. Madhavi. "Improvement of damping properties of structural member using soft material at support." International Journal of Engineering & Technology 7, no. 3 (June 26, 2018): 1216. http://dx.doi.org/10.14419/ijet.v7i2.18.10130.
Full textAbstract:
Coincidental plane vibration in the midst of flight isn't unusual. There are different purposes behind plane vibration, including landing gear increase and withdrawal, extension of speed brakes, free play in versatile surfaces, and breakdowns of frameworks. Air vehicles have an airframe structure which incorporates every single auxiliary part. This task manages Improvement of damping properties of the basic part utilizing a delicate material at the help. So in this task considered a cantilever auxiliary part made up of composite and aluminum materials and delicate material is elastic, settling for support. How the damping properties are changing in basic part with and without delicate material, and discover which structure is having higher damping properties. Consequently, the objective of the present work is to demonstrate that the damping will enhance when the delicate material utilized at the help and composite has higher damping than aluminum.