Initial noise measurements were performed on a 200kW vertical axis wind turbine (VAWT) and results were compared to that of a Vestas V27, a similar size horizontal axis wind turbine (HAWT). Multipl ...

The customer’s demands for higher quality,faster delivery times and reduction of cost,give evidence for the need to develop new technologies or enhance existing technologies combined with research activities. The automotive industry’s capability to develop newproducts in a shorter time is constantly improved. Tool and die creation is a major part of the product creation for many industrial products and in particular for the automotive industry. The higher product requirements on reduced weight,better safety,and lower emissions have meant that a larger number of automotive body parts must be made in advanced high strength steels. Improved functionality of surface textures and engineered tailor made component surfaces is one enabling technology for industry to increase compete ability by improved component function and reduced friction losses. However,material properties’ variation,un-evenly spread wear,unknown manufacturing process variations,the "human factor",faulty metrology procedures… All factors interact to increase the problems of utilizing surface texturing on the micro metre level as a competitive tool for industry. Large variation of the micro topography created by industrial machining processes tends to reduce the impact of the usage of improved engineered surfaces on critical components. A proposal of a strategy for metrology using "intelligent"sampling techniques comprising of regionalization of the functional area and designed sampling patterns is presented. To efficiently make use of efficient sampling,an example of a recently developed optical scattering light in-line metrology of high precision surfaces is discussed as a tool to enable efficient control of machine tools in general. Future steps discussed include developing of control loops for implementation in CNC controllers to efficiently make use of the "smart"surface texture characterisation data from the developed in-line surface texture sensors.更多还原

This paper presents observations of audio noise in frequency range 20-20 000 Hz from wind turbines. The observations were performed around the theoretically calculated 40 dBA noise perimeter around the wind turbine farm at Oxhult, Sweden. This paper describes a newly designed and constructed a field qualified data acquisition system to measure spectra and total noise level of sound from wind turbines. The system has been calibrated at SP Boras. It is shown that it has a flat frequency response and is linear with amplitude and time.The total noise level (as integrated 20-20 000 Hz) is shown to be below 35 dBA (below the reference background noise at 36 dBA) at a 10 m altitude wind speed of 4-5 m/s. The measurements were made along the theoretical 40 dBA border at 8 m/s.It is concluded that the theoretical 40 dBA border seems reasonable calculated if the manufacturer specifications are used to extrapolate the sound level to correspond to 8 m/s at 10 m. Our data indicate that a simple sound propagation model is sufficient since the sound level is more affected by the nearby environment than the large scale forest structure. Also, the large scale forestry structure is bound to change with time and the error bars of measurements on total sound level are about 1 dBA, which is larger than any fine tuning with a more sophisticated model. More care should be taken to model the reflections from walls and other obstacles close to the microphones.The distribution of the spectral noise level around the turbine farm suggests that the noise originates from individual wind turbines closest to the measurement location rather than from the wind turbine farm as a whole. The spectra show narrow band spectral line features which do not contribute significantly to the total noise at this level. The narrow band features are only detectable at very long integration time and at 1 Hz spectral resolution. The spectral features are typical to originate from mechanical noise.The spectral acquisition method described in this paper can be used as a field qualified system for sound measurements in forest areas. The high spectral resolution is a viable remote diagnostic method for mechanical faults in the turbine machinery. Future work will concentrate on these two areas. (C) 2013 Elsevier Ltd. All rights reserved.

The accumulation of deposits in the honing grooves of the cylinder liner surfaces of internal combustion engines is undesirable as they seal the grooves (reducing their oil retention capability) and increase engine's oil consumption. As part of a long-term programme of truck engine development, after different running times and under similar conditions of load, engine speed and lubrication, a number of grey iron cylinder liners were axially sectioned, measured, inspected and a presence of deposits was discovered. These deposits were characterised in order to gain knowledge about their origin and quantities. The X-ray energy dispersive analysis revealed elements stemming from the oil/fuel (C, O and S), from the detergent (Ca and Mg), from the anti-wear additive (Zn and P), and from some contaminants (K and Si). Higher concentration of S and Ca were mostly found in the honing grooves covered with deposits suggesting a domination of the detergent additive. Deposit thickness measurements obtained by a white light interferometer revealed patchy deposit topographies concentrated at the top region reducing towards the bottom of the liner which was also confirmed by scanning electron microscope measurements. Despite the limitations of the interferometer, it has been shown that the interference measurements are sufficiently reliable for a quick and objective quantification of the overall deposit accumulation. (C) 2010 Elsevier B.V. All rights reserved.

This paper presents topographic measurements of metal surface with Point Diffraction Interferometer (PDI) technique. Interferogram of a surface is created and recorded with different phase offsets. These are then combined to create a phase offset map of the surface. We demonstrate the use with the presentation of our first surface topographic map,

Polymeric films containing azobenzene fragments with donor and acceptor groups were produced as well as films of polycomplexes of these fragments with cobalt. Absorption spectra of these films before and during application of an external electric field were investigated. Electro-optical properties of the films are conditioned by spatial reorientation of dipole moments of azobenzene groups induced by polarized light in an external electric field. Increase in dipole moments of azobenzene groups reduces the influence of cobalt ions on the electro-optical properties of the polycomplex films. In the proposed phenomenological model, the electro-optical effect is explained by effect of induced forces upon azobenzene isomers and metallic ions.

A planar patch antenna array has been made for radar interferometry. The antenna array consists of 32 rectangular patches on a ceramic loaded teflon substrate. The patches are individually coupled to the microwave electronics in two orthogonal circular polarizations. The radar interferometer is intended for topographic imaging in industrial environment, in this case, a blast furnace producing hot metal for the steel and metal industry. Ordinary imaging techniques with IR or visible radiation are not possible to use due to high temperatures, scattering from dust and particles. A model of blast furnace burden material surface was measured and detected.

Thermal dependent changes of light depolarization degree were observed in the SnO2:In2O3 (ITO) layers deposited onto the flat glass substrates which are used usually as electrodes for optoelectronic devices. The observed effect is reversible. It can be attributed to the changes of nanostructure geometry in the bulk of the ITO layer as well as on its surface. Such geometric changes involve dispersion of polarized light. The investigated effect should be taken into consideration when developing optoelectronic devices because it can provoke distortion of the optical information field. (c) 2006 American Institute of Physics.