Search

The paper presents an approach and results of testing experiments on new modification of panoramic optical technique to register heat flux distributions (the Global Heat Flux Interferometry). The improvement was developed in order to overcome the difficulties of application of the method for curved surfaces and in continuously operating wind tunnels. As a sensor a combination of a thin heat sensitive layer and an electrical heater is used. The test experiments were done with subsonic impinging jet and flat plate model placed in supersonic flow. The results revealed the usage of such type of thin film sensors to be promising to register/visualize heat flux fields. [ABSTRACT FROM AUTHOR]

Damage detection of wind turbine blades is difficult due to their complex geometry and large size, for which large deployment of sensing systems is typically not economical. A solution is to develop and deploy dedicated sensor networks fabricated from inexpensive materials and electronics. The authors have recently developed a novel skin-type strain gauge for measuring strain over very large surfaces. The skin, a type of large-area electronics, is constituted from a network of soft elastomeric capacitors. The sensing system is analogous to a biological skin, where local strain can be monitored over a global area. In this paper, we propose the utilization of a dense network of soft elastomeric capacitors to detect, localize, and quantify damage on wind turbine blades. We also leverage mature off-the-shelf technologies, in particular resistive strain gauges, to augment such dense sensor network with high accuracy data at key locations, therefore constituting a hybrid dense sensor network. The proposed hybrid dense sensor network is installed inside a wind turbine blade model, and tested in a wind tunnel to simulate an operational environment. Results demonstrate the ability of the hybrid dense sensor network to detect, localize, and quantify damage. [ABSTRACT FROM AUTHOR]

Damage detection of wind turbine blades is difficult due to their complex geometry and large size, for which large deployment of sensing systems is typically not economical. A solution is to develop and deploy dedicated sensor networks fabricated from inexpensive materials and electronics. The authors have recently developed a novel skin-type strain gauge for measuring strain over very large surfaces. The skin, a type of large-area electronics, is constituted from a network of soft elastomeric capacitors. The sensing system is analogous to a biological skin, where local strain can be monitored over a global area. In this paper, we propose the utilization of a dense network of soft elastomeric capacitors to detect, localize, and quantify damage on wind turbine blades. We also leverage mature off-the-shelf technologies, in particular resistive strain gauges, to augment such dense sensor network with high accuracy data at key locations, therefore constituting a hybrid dense sensor network. The proposed hybrid dense sensor network is installed inside a wind turbine blade model, and tested in a wind tunnel to simulate an operational environment. Results demonstrate the ability of the hybrid dense sensor network to detect, localize, and quantify damage. [ABSTRACT FROM AUTHOR]

In the present investigation V2O5 thin films were prepared by spray pyrolysis by varying substrate to nozzle distance (SND) from 20 to 35 cm in steps of 5 cm. The structural studies by XRD results indicates that the crystallinity increases with increase in SND along (101), (201) orientation and for the film prepared at 30 cm gives a good crystallinity. The SEM image shows that the change in morphology, which strongly depends on the SND. Above 30 cm it slightly affects the surface morphology of the V2O5 thinfilm due to agglomeration. The presence of elemental constituents is confirmed from EDAX analysis. The band gap of the film prepared at 30 cm has a lowest value of 2.1 eV. The electrical studies like I-V, Hall Effect measurement and the conductivity is maximum for the film prepared at 30 cm. The ethanol sensing of the prepared film has been studied using Keithley source meter and the detailed results are presented and discussed. [ABSTRACT FROM AUTHOR]