Sonderdruck / Schriftenreihe der Georg-Simon-Ohm-Hochschule, Nürnberg
Refine
Document Type
- Report (11)
Language
- English (11) (remove)
Has Fulltext
- yes (11)
Keywords
- Emissionsverringerung (2)
- Mixture Direct Injection (2)
- Porous Medium Technology (2)
- Verbrennungsmotor (2)
- combustion system (2)
- engine emission (2)
- 26 Mhz (1)
- CAM (1)
- DRM <Rundfunktechnik> (1)
- Data Encryption Standard (1)
49
On May 6th 1971 the worldwide first MAGLEV vehicle was presented by Messerschmitt-Bölkow-Blohm (MBB) in Ottobrunn near Munich, Germany. Till the year 2000 different test and application MAGLEV vehicles followed, but no commercial use in Germany. Since December 31st 2002 the Shang-hai MAGLEV Transportation System is successfully in operation, as the worldwide first and only one commercial used MAGLEV line. The paper in honour of Prof. Dr.-Ing. Eveline Gottzein for her 80th birthday contains in the reference list her scientific publications about MAGLEV vehicle control systems.
40
Basic aspects of a high velocity Diesel jet interaction with small cylindrical obstacles are presented in the paper. The phenomenon discussed in the paper lies between cylinder overflow and jet impingement on to solid wall. Especially the effect of high velocity Diesel jet “destruction” and its distribution in space are investigated in the paper. As shown, the dominant role in this process plays a fist obstacle: its diameter, distance from the nozzle outlet and injection pressure play a dominant role in characterization of the jet distribution in space. The jet spatial distribution bases on a multi-jet model. By Diesel jet impingement on a single obstacle with smaller diameter the distribution angle decreases with increasing injection pressure. For bigger obstacle the angle separating both jets increases being almost independent of the injection pressure. This angle does not change with time after impingement process, however decreases with increasing distance between nozzle and the obstacle. For Diesel jet impingement on more than single obstacle, the jet distribution depends on the obstacle geometrical configuration but not necessarily on the number of obstacles. As shown in the paper quite similar distribution has been obtained for three and eight obstacles configurations. Presented phenomenological model explains this observation. There is possible to design such configuration of small obstacles which permit very good charge homogenization in defined space (combustion chamber).
36
The Sky Train at Dortmund University campus is a driverless transit system. Cabins suspended from the elevated guideway glide along towards to their destination. The vehicles can run on the double track route at one-minute intervalls with a nominal speed of 50 km/h. The guideway consists of boxshaped steel beams with a narrow slot on bottom. With its structure it forms the inside support wheel and guidance wheel tracks for the bogies. The passenger cabins hanging on the bogies are oscillating in lateral direction influenced by the periodic track irregularities. For different system parameters the response of the lateral cabin acceleration at the center of gravity is determined by frequency response analysis and computer simulation. It is shown that by optimizing the design parameters the passenger ride comfort in lateral direction can be improved enormously. Further improvement is possible only by active control. The original version of the paper was presented on the Second International Conference on Dynamics, Vibration and Control, Beijing, P.R. China 2006.
32
The paper describes application of a highly porous open cell structures to internal combustion engines for supporting mixture formation and combustion processes. Porous structures, materials and their properties for engine application are discussed in this paper. Especially application to a high temperature combustion processes are considered. Novel concepts for internal combustion engines based on the application of porous medium technology are presented and discussed. The main attention is focused on the engine concepts having potential for homogeneous (nerly emissions free) combustion process under variable engine operational conditions. It is shown that porous media can be used for a great variety of improvements in the combustion process. The key role for NOx reduction and soot emission ellimination is a homogeneous combustion in engine. This can be realised by homogeneous mixture formation, and a 3D ignition preventing from formation of a flame front having a temperature gradient a in the entire combustion volume. All these processes: gas flow, fuel injection and its spatial distribution, vaporization, mixture homogenization, ignition and combustion can be controlled or positively influenced with the help of porous media/ceramic reactors.
31
Using DRM in the 26 MHz band is an interesting option for local braodcasting. A field trial was set up with two low power DRM transmitters in the area of Nuremberg. Mobile reception was found to be possible at distances of up to 20 km to the transmitter. However, audio dropouts due to flat fading in the multipath channel were frequently observed at low vehicle speed. Fixed reception with outdoor antennas was found to be possible at distances of more than 40 km. An overall availability of the audio signal of 99.2 % was achieved at seven different locations during ten days. Long term recordings of several hundreds of hours at one location showed that audio availability was better than 97% in many cases but was reduced at times by local sources of noise and interfering signals from distant stations when ionospheric scattering was possible due to high solar activity and sporadic E layers. Based on these findings it is concluded that for service planning the same procedures as for VHF transmitter networks can be applied. However to avoid interference by ionosperic scattering, cochannel transmitters must be seperated by at least 2500 km. Therefore, only one channel will be available in each place.
26
In this report the author proposes strategy for development of intelligent combustion systems with a goal to approach a near-zero emission internal combustion engine operating in a wide range of speeds and loads. Main requirement for future I.C. engine is to develop a system permitting homogeneous combustion process (minimum of engine emissions) under all operational conditions. The author suggests, that none existing individual combustion system may satisfy these conditions. However, combination of different individual combustion modes in a one system may permit homogeneous combustion in a wider range of loads. Such combination of individual systems having potential for a homogeneous combustion and operating in different ranges of engine loads is here defined as an intelligent engine. In order to make this strategy practicable a new concept for mixture formation (MDI-Mixture Direct Injection) and homogeneous combustion based on the Porous Medium (PM)- technology is proposed in this paper. This is probably first publication indicating possibility of developing of intelligent combustion systems in engines. This paper concentrates on MDI system that may adopt an actual combustion mode realizing in engine (i.e. ignition and combustion conditions) to actual engine operational conditions
23
In 2020 Malaysia will be a highly developed industrialized country. This aim is described in the Vision 2020 program. And Malaysia acts accordingly and founded five application oriented universities in the recent 2 1/2 years. How to set up application oriented universities and how to educate highly qualified application oriented engineers were the main topics of the 1st National Convention on Engineering Education: Profession Oriented Approach in Putrajaya, Malaysia, July 7-9, 2003. The author has been invited by the conference organisors to give a keynote speech on the economic relevance of Fachhochschulen to the German economy because Germany's professional and application oriented education system is a preferred reference model. This paper presents statistical evidence that Fachhochschulen are indispensable to the German higher education and economy.
9
This paper discusses the possibilities of IPtechnologies for information protection. An analysis of modern information protection Soft-Cores which support symmetric block ciphers is given. Development perspectives of the Soft-Cores are described. The DES Algorithm and the variations of the architecture of the DES Soft-Core models are considered, their analysis provided and they are compared with some existing DES Soft-Cores on the world market. Two architectures - iterative and pipelined - are identified. Twenty six variations of the DES Soft-Core are proposed and a comparative analysis of their architecture is given. The proposed DES Soft-Cores support all of the discussed functional possibilities. Thus a high performance is achieved, the equipment volume for their realization is lowered and they can be used effectively in a wide spectrum of the application fields.
7
This paper is dealing with teaching and leadership. As a contribution to the current discussion of the position and the role of professors at universities in Europe, a phenomenological-humanistic approach will be outlined (as part one). This approach has been applied to the feedback data by 3302 students from Germany and other countries evaluating their lectures of one professor from 1969 to 2000. The survey data were collected by the technique named "Semantic Differential" developed by Osgood and elaborated by Hofstätter. Interestingly, a remarkable pattern constituted by students´ attributions to their learning processes with the author has emerged from the late sixties to the actual millennium. Part two of this paper reflects statements of colleagues and students from all parts of Germany and abroad, too. In addition, a frame-work of socalled pedagogical leads as an underlying principle will be outlined. And the parts three and four offer typical examples of this approach to teaching. Part three presents a record of an old but still actual excursion in synectics titled "How our students of 1974 saw our world of 2000" elaborated by students of engineering and economics enrolled 1974. Finally, the part four comes with an actual example of our examinations for students of engineering enrolled in the compulsory / optional subject "Personality and creativity training".
5
Knowledge of the features and qualities of a machine element are essential foundations for its successful operation. High grade materials, more accurate calculation methods and modern manufacturing processes lead to continuous design and performance improvements and hence increased power within minimised spatial requirements. INA cylindrical roller bearings, series SL 1923.., ZSL 1923.. and LSL 1923.. follow this trend and due to their high performance characteristics and low physical volume they have obtained a firm place as high performance machine elements. Essential characteristics of radial cylindrical roller bearings are their behaviour regarding kinematics, noise, vibration, dynamic frictional torque, cage speed, speed of a rolling element, slip etc. The paper gives details of the kinematic behaviour concerning the relationship between the roller set speed or the cage speed and the speed of a rolling element in connection with the occurrence of smearing. This kind of damage occurs during the running in stage of a machine and is becoming very important because of the enormous costs which are caused by down time and lost production.