Design of a Close Power Loop Test Bench for Contra-Rotating Propellers

2020 ◽  
Author(s):  
Antonio Giallanza ◽  
Ferdinando Morace ◽  
Giuseppe Marannano
Keyword(s):  
High Speed ◽  
Test Bench ◽  
Point Of View ◽  
Mechanical Transmission ◽  
Passenger Transport ◽  
Test Configuration ◽  
Bevel Gears ◽  
Commercial Applications ◽  
Kinematic Mechanisms ◽  
Very High

The aim of the research is to develop an azimuthing contra-rotating propeller for commercial applications with a power of 2000 kW. The thruster system is designed especially to be installed on high speed crafts (HSCs) for passenger transport with a cruising speed of about 35–40 knots. The topic is very useful because the azimuth thruster solutions currently do not find commercial applications in naval units for passenger transport. The latter are heavy, not very efficient from a hydrodynamic point of view and suitable for maximum cruising speed of about 18–20 knots. The study is interesting because among the advantages that these solutions provide are the possibility of transmitting very high torques and to guarantee a much longer life cycle. In more detail, the propulsion is realized by using a C-drive configuration, with a first mechanical transmission realized by using bevel gears mounted in a frame inside the hull, and a second transmission realized by bevel gears housed in a profiled hull at the lower end of a support structure. In the profiled hull will be installed the shafts of the propellers, in a contra-rotating configuration. In order to optimize the system before its industrial use, a close power loop test bench has been studied and designed to test high power transmissions. The test configuration allows to implement a back-to-back connection between two identical azimuthing contra-rotating propellers. Moreover, the particular test bench allows to size the electric motor simply based on the dissipated power by the kinematic mechanisms. Since the efficiency of these systems are very high, it is not necessary to use large electric motors, thus managing to contain the operating costs of the testing phase. The most significant disadvantage is the need to have two identical transmissions with consequent increase in installation costs. Through the back-to-back test bench it was possible to study the increase in efficiency compared to traditional systems.

Failure Mechanisms of TGV Brake Discs

2007 ◽  
Vol 345-346 ◽  
pp. 697-700 ◽  
Author(s):  
Gérard Degallaix ◽  
Philippe Dufrénoy ◽  
Jonathan Wong ◽  
Paul Wicker ◽  
Frédéric Bumbieler
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Test Bench ◽  
Infrared Camera ◽  
Second Step ◽  
Brake Disc ◽  
Disc Brakes ◽  
Brake Discs ◽  
High Speed Trains ◽  
Very High

The CRISFIS project (supported by ADEME agency) consists in jointly studying the squealing and cracking aspects of the high power disc brakes for TGV very high speed trains. This paper deals with the progress concerning the cracking part. An experimental and modelling strategy is adopted in order to better understand and predict brake disc cracking. Braking tests conducted on an industrial scale-one test bench are presented. In a first step, the influence of the pad-type on the thermal loading applied to the disc is studied by means of an infrared camera and thermocouples embedded in the pads and in the disc. In a second step, the thermal maps extracted from thermographic monitoring are used as input data for thermal-mechanical calculations. Finally, the results of modelling and tests are compared to the damage observed on the brake discs.

scholarly journals Assessment of Priorities of Construction of High-Speed Rail in the Czech Republic in Terms of Impacts on Internal and External Integration

2020 ◽  
Vol 20 (2) ◽  
pp. 217-241
Author(s):  
Vilém Pařil ◽  
Milan Viturka
Keyword(s):  
Czech Republic ◽  
High Speed ◽  
Quality Parameters ◽  
Point Of View ◽  
Passenger Transport ◽  
High Speed Rail ◽  
The Czech Republic ◽  
Metropolitan Regions ◽  
The Road ◽  
Primary Basis

AbstractThe priorities assessment for the planned construction of high-speed rail/HSR in the Czech Republic in terms of impacts on internal and external integration is a though-provoking topic not only from the technical and economic, but also from the social and geographical point of view. Its primary basis is the application of the gravity model, according to which the planned route C Prague-Wien has the most significant potential in passenger transport. Then following routes are A Prague-Berlin, B Prague-München, and D Brno-Katowice. Subsequently, the likely impacts generated by a significant improvement in the quality parameters and hence the competitive position of rail transport were assessed, including the potential for shifting part of the demand from the road and air transport to HSR. Overall, however, it can be stated that the potential impacts of the HSR on the growth of passenger transport in the Czech Republic will not be essential. To perceive the regional impacts of HSR construction, analyses of selected indicators (population density per km2, GDP per capita, unemployment rate) by NUTS 3 regions for the period 2007-2017 were also carried out. From the strategic point of view, the research results did not confirm that the planned construction of the HSR primarily stimulates convergence tendencies in regional development as the main priority of EU regional policy. Rather, it seems more likely that the HSR will stimulate the extraction of economic activity from “rural” regions in favour of metropolitan regions.

The calculation of the latent roots and vectors of matrices on the pilot model of the A.C.E.

1954 ◽  
Vol 50 (4) ◽  
pp. 536-566 ◽  
Author(s):  
J. H. Wilkinson
Keyword(s):  
Differential Equations ◽  
High Speed ◽  
Storage Capacity ◽  
Eigenvalue Problems ◽  
High Accuracy ◽  
Point Of View ◽  
Aircraft Industry ◽  
Pilot Model ◽  
Very High ◽  
Latent Roots

ABSTRACTThe problem of finding the latent roots and vectors of matrices has been treated in a number of papers ((2)–(7)) mainly from the point of view of desk computers. In this paper the problem is treated from the standpoint of users of high-speed automatic computers. In the first section a number of iterative processes are described and, in the second, the techniques developed for using these processes on the Pilot Model of the Automatic Computing Engine. It is shown that the methods give very high accuracy and can be used to deal with matrices of high orders even on a machine of very limited storage capacity. They have been used on numerous matrices of orders up to 60 mainly on problems arising in the aircraft industry and on eigenvalue problems for systems of ordinary differential equations.

The Development of Friction Pairs for Intermediate to Very High Duty Railway Applications

1994 ◽  
Vol 208 (2) ◽  
pp. 109-113
Author(s):  
K D Dolbear ◽  
J C Watson
Keyword(s):  
High Speed ◽  
High Performance ◽  
Point Of View ◽  
Railway Vehicle ◽  
Vehicle Design ◽  
Large Spread ◽  
Challenges And Opportunities ◽  
Ceramic Interfaces ◽  
Very High

Railway vehicle service speeds are set to increase from the present 300 km/h. These developments are being spearheaded by the French, German, Italian and Japanese railways. It is also clear in other less glamorous areas such as freight and suburban operations, that the trends in vehicle design are going to put severe burdens on the braking technology available today. These initiatives included the advanced suburban bogie for British Railways. While it will be possible to squeeze some further improvements out of conventional products, it has become essential to initiate work on new materials which not only meet the immediate demands but address the requirements of the middle- and long-term. Some proposals such as carbon/carbon may be impractical from a cost point of view on anything other than exotic high-speed vehicles but studies involving ceramic to ceramic interfaces are proving interesting with a real possibility of providing high performance at an economical cost for a large spread of applications. The paper will discuss some of the challenges and opportunities to be grasped and solved.

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

YSS HAP72

Alloy Digest ◽  
2019 ◽  
Vol 68 (10) ◽  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Tool Steel ◽  
High Speed ◽  
High Wear Resistance ◽  
Bend Strength ◽  
Temperature Performance ◽  
Very High

Abstract YSS HAP72 is a powder metallurgy high-speed tool steel with a very high wear resistance. This datasheet provides information on composition, hardness, and bend strength. It also includes information on high temperature performance. Filing Code: TS-779. Producer or source: Hitachi Metals America Ltd.

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

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