scholarly journals Innovative braking system for high-speed 80-foot platform

2021 ◽  
Vol 80 (6) ◽  
pp. 343-350
Author(s):  
V. A. Nikonov ◽  
V. F. Zubkov ◽  
M. N. Tsibizov ◽  
I. V. Nazarov ◽  
D. V. Gorskiy

The article discusses technical solutions for the creation of an effective design of a brake system for high-speed longwheelbase platforms intended for the transport of containers, as well as for the development of a fundamentally new brake equipment for the pneumatic, electro-pneumatic and mechanical parts of the brake system. Modular braking equipment for the pneumatic and electro-pneumatic parts of the high-speed platform braking system, compactly located under the platform frame, provides technical compatibility when controlling platform brakes as part of not only a high-speed freight train of permanent formation, but also in trains for other purposes, regardless of the location of the platform in the composition of the train. The performance of the braking equipment of each platform in motion and in the parking lot is monitored using pressure sensors and an electronic unit that processes the readings of the sensors and transmits information to the locomotive via one of the wire lines of the electro-pneumatic brake. The brake rigging used on the high-speed platform is arranged in the design of three-axle bogies and provides doublesided pressing on the wheels with typical composite brake pads, automatic regulation and maintenance of the standard clearances between brake pads and wheels. The proposed promising technical solutions make it possible to continuously diagnose the parameters of the brakes of each platform as part of a permanent train, display them on the locomotive monitor and transmit them to the dispatch centers of the Russian Railways infrastructure. Thanks to this, the braking effciency can be increased and the safety of train traffc can be ensured while increasing the permissible travel speeds. In the modern concept of digitalization of the infrastructure of Russian Railways, which provides for the creation in 2021–2025 (and in the future until 2030) of cars in which intelligent technologies should be applied, the braking system of a high-speed platform can be considered as the basis for creating a digitally controlled train — one of the key elements of the digital railway.

2017 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Muhammad Mushlih Elhafid ◽  
Didik Djoko Susilo ◽  
Purwadi Joko Widodo

This study aims to determine the effect of brake pads material to the vibration response of disc brake system on many variety of braking conditions. The variations of brake pads material on this research such as metallic, non-asbes and ceramic. The variations of braking operation such as speed of disc rotation and braking pressure. Each brake pads material tested by variation of disc rotation 425, 637, 850, 1062 rpm and pressure variation 0,5 bar, 1 bar, 1,5 bar. Furthermore, the dynamic characteristics of brake pad had been tested by using the method of Modal Analysis Experiment. The results showed that the type of brake pad materials, disc rotation and braking pressure affect to vibration response of disc brake system. Increasing speed of disc rotation and braking pressure will increase the excitation force causing value amplitude of vibration in the braking system increases. Usage of brake pad ceramic also showed the lowest amplitude of vibration for all variations of disc rotation and braking pressure. Because the ceramic brake pad have the lowest natural frequency, then the value of the damping ratio is high, so that decreasing amplitude of vibration that occurs in the braking system.


2021 ◽  
Author(s):  
Jiabao Yin ◽  
Yuanke Wu ◽  
Chun Lu ◽  
Wei Chen ◽  
Jiliang Mo ◽  
...  

Abstract The influence of friction blocks connection configuration on the interfacial tribology behavior and FIVN (friction-induced vibration and noise) of high-speed railway braking system is systematically investigated with a scaled brake test bench. The potential relationship among interface contact status, friction, wear, pressure distribution, heat distribution and vibration noise of the system is studied under dragging test condition. The results indicate that the connection configuration of the friction blocks has a significant impact on systematic interfacial tribology behavior, heat distribution and vibration noise. A floating connection mode can suppress the vibration noise of brake system. The interfacial heat distribution and systematic vibration noise are quite relevant with the contact status, interfacial wear and pressure distribution. The increase of interfacial wear will lead to an expansion of pressure concentration area and an aggravation of vibration noise. The result of this research is helpful for a further design optimization and noise reduction of railway brake system.


2011 ◽  
Vol 69 ◽  
pp. 28-32 ◽  
Author(s):  
Yu Wang ◽  
Li Lin

With the development of oil exploration and electronics technology, the automation control technologies of hydraulic disc brake system (HDBS) have become more and more widely used. After analysis the braking performance of HDBS, The optimizing schemes for hydraulic disc brake, such as PWM high speed on/off valve and pressure switch are used in the constant weight auto-drilling system. It has been tested successfully both on the integrated braking facility in lab and in the oil field. And it proved that the PWM valve have great prospects on the braking system.


2021 ◽  
Vol 9 (1) ◽  
pp. 67
Author(s):  
Hiroshi Takagi ◽  
Fumitaka Furukawa

Uncertainties inherent in gate-opening speeds are rarely studied in dam-break flow experiments due to the laborious experimental procedures required. For the stochastic analysis of these mechanisms, this study involved 290 flow tests performed in a dam-break flume via varying gate speeds between 0.20 and 2.50 m/s; four pressure sensors embedded in the flume bed recorded high-frequency bottom pressures. The obtained data were processed to determine the statistical relationships between gate speed and maximum pressure. The correlations between them were found to be particularly significant at the sensors nearest to the gate (Ch1) and farthest from the gate (Ch4), with a Pearson’s coefficient r of 0.671 and −0.524, respectively. The interquartile range (IQR) suggests that the statistical variability of maximum pressure is the largest at Ch1 and smallest at Ch4. When the gate is opened faster, a higher pressure with greater uncertainty occurs near the gate. However, both the pressure magnitude and the uncertainty decrease as the dam-break flow propagates downstream. The maximum pressure appears within long-period surge-pressure phases; however, instances considered as statistical outliers appear within short and impulsive pressure phases. A few unique phenomena, which could cause significant bottom pressure variability, were also identified through visual analyses using high-speed camera images. For example, an explosive water jet increases the vertical acceleration immediately after the gate is lifted, thereby retarding dam-break flow propagation. Owing to the existence of sidewalls, two edge waves were generated, which behaved similarly to ship wakes, causing a strong horizontal mixture of the water flow.


Author(s):  
Jacqueline Barber ◽  
Khellil Sefiane ◽  
David Brutin ◽  
Lounes Tadrist

Boiling in microchannels remains elusive due to the lack of full understanding of the mechanisms involved. A powerful tool in achieving better comprehension of the mechanisms is detailed imaging and analysis of the two phase flow at a fundamental level. We induced boiling in a single microchannel geometry (hydraulic diameter 727 μm), using a refrigerant FC-72, to investigate several flow patterns. A transparent, metallic, conductive deposit has been developed on the exterior of rectangular microchannels, allowing simultaneous uniform heating and visualisation to be conducted. The data presented in this paper is for a particular case with a uniform heat flux of 4.26 kW/m2 applied to the microchannel and inlet liquid mass flowrate, held constant at 1.33×10−5 kg/s. In conjunction with obtaining high-speed images and videos, sensitive pressure sensors are used to record the pressure drop profiles across the microchannel over time. Bubble nucleation, growth and coalescence, as well as periodic slug flow, are observed in the test section. Phenomena are noted, such as the aspect ratio and Reynolds number of a vapour bubble, which are in turn correlated to the associated pressure drops over time. From analysis of our results, images and video sequences with the corresponding physical data obtained, it is possible to follow visually the nucleation and subsequent both ‘free’ and ‘confined’ growth of a vapour bubble over time.


Author(s):  
Jingjing Luo ◽  
Dieter Brillert

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB, the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.


2021 ◽  
Vol 1 (142) ◽  
pp. 163-177
Author(s):  
Vyacheslav V. Kosenko ◽  
◽  
Vladimir V. Sharov ◽  
Yuliya S. Tsench ◽  
◽  
...  

The article, dedicated to the 35th anniversary of the start of production at the Volgograd Tractor Plant of the tracked agricultural tractor DT-175S "Volgar", tells about the history of the creation of this unique machine in its own way. (Research purpose) The research purpose is in analyzing the history of the creation and production, the effectiveness of the use of the DT- 175S "Volgar" tractor, considering the stages and directions of its improvement. (Materials and methods) The article de-scribes the history of the creation of the high-speed energy-saturated tractor "Volgar", gave its design features, technical characteristics in comparison with its predecessors, the results of tests in various soil and climatic zones, on various agricultural operations. (Results and discussion) In the DT-175S "Volgar" tractor, the designers, in close cooperation with scientists, embodied the results of research aimed at increasing the working speeds of machine-tractor units, and the most advanced technical solu-tions in the field of tractor construction at that time. The main of these solutions is an automatic continuously variable hydro-mechanical transmission. The combination of a powerful (125 kilowatt) engine with a similar transmission allowed not only signifi-cantly increase the working speed and productivity of the tractor, up to 9-15 kilometers per hour, but also significantly reduce the labor intensity of the tractor driver. The article presents the information about the improvement, modernization of the tractor, the creation of various specialized modifications on its basis. DT-175S "Volgar" be-came the most powerful serial machine of the Volgograd Tractor Plant, rightfully earned the respect of specialists of farms and machine operators. (Conclusions). Further development of the application of the automatic hydro-mechanical transmission on agricultural tractors was to receive the VT-200D tractor of 5th traction class with a capacity of 147 kilowatts. Due to the complication of the economic situation, the production of this tractor was lim-ited to only a small experimental batch.


Author(s):  
Adam R. Hickman ◽  
Scott C. Morris

Flow field measurements of a high-speed axial compressor are presented during pre-stall and post-stall conditions. The paper provides an analysis of measurements from a circumferential array of unsteady shroud static pressure sensors during stall cell development. At low-speed, the stall cell approached a stable size in approximately two rotor revolutions. At higher speeds, the stall cell developed within a short amount of time after stall inception, but then fluctuated in circumferential extent as the compressor transiently approached a stable post-stall operating point. The size of the stall cell was found to be related to the annulus average flow coefficient. A discussion of Phase-Locked Average (PLA) statistics on flow field measurements during stable operation is also included. In conditions where rotating stall is present, flow field measurements can be Double Phase-Locked Averaged (DPLA) using a once-per-revolution (1/Rev) pulse and the period of the stall cell. The DPLA method provides greater detail and understanding into the structure of the stall cell. DPLA data indicated that a stalled compressor annulus can be considered to contained three main regions: over-pressurized passages, stalled passages, and recovering passages. Within the over-pressured region, rotor passages exhibited increased blade loading and pressure ratio compared to pre-stall values.


Author(s):  
Kevin Prieur ◽  
Daniel Durox ◽  
Thierry Schuller ◽  
Sébastien Candel

This article reports experiments carried out in the MICCA-spray combustor developed at EM2C laboratory. This system comprises 16 swirl spray injectors. Liquid n-heptane is injected by simplex atomizers. The combustion chamber is formed by two cylindrical quartz tubes allowing full optical access to the flame region and it is equipped with 12 pressure sensors recording signals in the plenum and chamber. A high-speed camera provides images of the flames and photomultipliers record the light intensity from different flames. For certain operating conditions, the system exhibits well defined instabilities coupled by the first azimuthal mode of the chamber at a frequency of 750 Hz. These instabilities occur in the form of bursts. Examination of the pressure and the light intensity signals gives access to the acoustic energy source term. Analysis of the phase fluctuations between the two signals is carried out using cross-spectral analysis. At limit cycle, large pressure fluctuations of 5000 Pa are reached, and these levels persist over a finite period of time. Analysis of the signals using the spin ratio indicates that the standing mode is predominant. Flame dynamics at the pressure antinodal line reveals a strong longitudinal pulsation with heat release rate oscillations in phase and increasing linearly with the acoustic pressure for every oscillation levels. At the pressure nodal line, the flames are subjected to large transverse velocity fluctuations leading to a transverse motion of the flames and partial blow-off. Scenarios and modeling elements are developed to interpret these features.


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