The energy industry is undergoing a major upheaval. In Germany, for example, the large nuclear and coal-fired power plants in the gigawatt scale are planned to be shut down in the forthcoming years. Electricity is to be generated in many small units in a decentralized, renewable and environmentally friendly manner. The large 1000 MW multistage axial steam turbines used to this date are no longer suitable for these tasks. For this reason, the authors examine turbine architectures that are known per se but have fallen into oblivion due to their inferior efficiency and upcoming electric drives about 100 year ago. However, these uncommon turbine concepts could be suitable for small to micro scale distributed power plants using thermodynamic cycles, which use for example geothermal wells or waste heat from industry to generate electricity close to the consumers. Thus, the paper describes and discusses the concept of a velocity-compounded single wheel re-entry cantilever turbine in comparison with other turbine concepts, especially other velocity-compounded turbines like the Curtis-type. Furthermore, the authors describe the design considerations, which led to a specific design of a 5 kW air turbine demonstrator, which was later manufactured and investigated. Finally, first numerical as well as experimental results are presented, compared and critically discussed with regards to the originally defined design approach.

The velocity field around the standard Rushton turbine was investigated by the Laser Doppler Anemometry (LDA) and Particle Image Velocimetry (PIV) measurements. The mean ensembleaveraged velocity profiles and root mean square values of fluctuations were evaluated at two different regions. The first one was in the discharge stream in the radial direction from the impeller where the radial flow is dominant and it is commonly modelled as a swirling turbulent jet. The validity range of the turbulent jet model was studied. The second evaluated region is under the impeller where flow seems to be at first sight rather rigorous but obtained results show nonnegligible values of fluctuation velocity.

The paper presents the problem of sensorless control of a permanent magnets synchronous motor (PMSM) without a damping cage for fan applications. Frequency control was used according to the principle of v/f = const. In order to reduce the power consumption of the drive system, the optimal voltage to the motor frequency characteristics was tested in the laboratory. The experimental studies was performed on a laboratory set of a drive consisting of two coupled PMSM machines, where one machine was supplied by a transistor inverter and the other was a passive load. A new criterion based on minimizing the module of stator current vector was proposed and an optimization algorithm in steady states was tested. The results of laboratory tests confirmed the validity of the applied solution for the fan drive.

Results of velocity measurements of liquid and gas bubbles in a tank with a self-aspirating disk impeller are analysed. Studies were carried out using a fluorescent dye tracer in the measuring system with two cameras (simultaneous phase velocity measurement) and with one camera (sequential measurement of phase velocity). Based on a comparative analysis of the acquired data it was found that when differences in the phase velocities were small the simultaneous velocity measurement gave good results. However, sequential measurement gives greater possibilities for setting the measuring system and if the analysis of instantaneous velocities is not necessary, it seems to be a better solution.

The aim of the project was to collect experimental data regarding local distributions of fluid velocity and inert tracer concentration in a tank reactor with turbulent flow. The experiments were performed in a microscale in a region of tracer fluid injection. The results of experiments can be used for direct validation of currently developed CFD models, particularly for time-dependent mixing models used in LES.

Velocity is one of the main navigation parameters of moving objects. However some systems of position estimation using radio wave measurements cannot provide velocity data due to limitation of their performance. In this paper a velocity measurement method for the DS-CDMA radio navigation system is proposed, which does not require full synchronization of reference stations carrier frequencies. The article presents basics of FDOA (frequency difference of arrival) velocity measurements together with application of this method to an experimental radio navigation system called AEGIR and with some suggestions about the possibility to implement such FDOA measurements in other kinds of asynchronous DS-CDMA radio networks. The main part of this paper present results of performance evaluation of the proposed method, based on laboratory measurements

The paper presents the results of simulation method for prediction of helicopter H-V zone envelope in the case of engine power loss. Depending on the loss rate of available power, the emergency maneuver for flight continuation is calculated, or the autorotation landing is predicted. The realization of an airborne device with in-built calculating procedure and graphic presentation of H-V zone predicted limits can improve safety level of helicopter flight, and can cue the pilot to make proper decision in emergency conditions. The results of emergency maneuver simulation were verified by comparing them with flight tests of Mi-2Plus helicopter for partial power unit failure, and with records of SW-4 helicopter autorotation landing. The operation of measurement-recording module, which consists of GPS receiver, inertial measurement unit and a computer of PC-104 standard, was checked during flight tests of a radio-controlled helicopter model.

The blasting technique is currently the basic excavation method in Polish underground copper mines. Applied explosives are usually described by parameters determined on the basis of specific standards, in which the manner and conditions of the tests performance were defined. One of the factors that is commonly used to assess the thermodynamic parameters of the explosives is the velocity of detonation. The measurements of the detonation velocity are carried out according to European Standard EN ­13631-14:2003 based on a point-to-point method, which determines the average velocity of detonation over a specified distance. The disadvantage of this method is the lack of information on the detonation process along the explosive sample. The other method which provides detailed data on the propagation of the detonation wave within an explosive charge is a continuous method. It allows to analyse the VOD traces over the entire length of the charge. The examination certificates of a given explosive usually presents the average detonation velocities, but not the characteristics of their variations depending on the density or blasthole diameter. Therefore, the average VOD value is not sufficient to assess the efficiency of explosives. Analysis of the abovementioned problem shows, that the local conditions in which explosives are used differ significantly from those in which standard tests are performed. Thus, the actual detonation velocity may be different from that specified by the manufacturer. This article presents the results of VOD measurements of a bulk emulsion explosive depending on the diameter of the blastholes carried out in a selected mining panel of the Rudna copper mine, Poland. The aim of the study was to determine the optimal diameter of the blastholes in terms of detonation velocity. The research consisted of diameters which are currently used in the considered mine.