Abstract: Failures of turbine blades are one of the most critical problems in power generating industry. Among the different failure mechanisms, resonant vibration of blades has a major role and therefore is the subject of many recent research works. Therefore, in this paper, modal analysis of a first stage blade in ALSTOM gas turbine is investigated and natural frequencies and vibration modes of blade are found in various conditions. For this purpose, a cloud-point model of a gas turbine blade has been created using 3D Laser Digitizer. Then the numerical calculation by finite element method using ANSYS software based on experimental test conditions is utilized and Experimental natural frequencies have been obtained. The results show acceptable agreement between the experimental and FEM results.
Abstract: To effectively reduce friction torque and start-up wind speed, magnetic bearing was applied to the small-scale wind turbine. Load analysis is the primary task of the design for magnetic bearing in wind turbine. Based on a typical blade model, the aerodynamic performance of the impeller was simulated using Computational Fluid Dynamics (CFD) method. The characteristics and differences of the impeller’s aerodynamic performance under different wind speeds were analyzed and the aerodynamic loads were calculated as well. Moreover, the bearing capacity of magnetic bearing was calculated according to the forces on the spindle. A kind of permanent magnetic bearing (PMB) was designed for the radial supporting of the spindle in wind turbine. A prototype of the small-scale maglev wind turbine (SMWT) was presented, which provides some basis for the application of magnetic bearings in wind turbines.
Abstract: Thermal lens microscopy (TLM) is a highly sensitive photothermal technique, and has found various applications in chemical analysis, especially when it is combined with lab-on-a-chip chemistry. In this paper, we analyze a couple of key characteristics of TLM, and give suggestions for optimization of the system for higher detection sensitivity, lower noise, lower irradiation density and/or better temporal and spatial resolutions. This will advance the development of TLM instrument for different chemical and biochemical analyses.
Abstract: In this paper, some tests was performed to evaluate the effect of scanning depth of field on the measurement error and the density of the point cloud obtained from the developed non-contact 3D scanner by measurement error of about ±0.05mm, which was taken from a single digital camera and a 3LCD video projector as a source projecting the structured light pattern. To perform this analysis, the scanning depth changes occurred in steps. However, due to the effect that the video projector focus has on the sharpness of the projected image pattern and consequently the measurement noise created, the tests were repeated again with the change in focus at every step. The experimental results suggest the need to define the optimum scanning depth (less than 60cm), to provide a stable and acceptable precision, and shows the great effect of scanning depth of field and sharpness of the projected pattern on the amount of measurement noise and density of the points cloud.
Abstract: Two-point method designed of the test system for application, the precision of the motorized spindle rotation was dynamic measurements. The system consists of standard bars, high-precision non-contact eddy current sensor. Analyzed by a mathematical model to establish error separation, measurement of two spindle rotation accuracy. The use of two isolated error method for processing the experimental data obtained spindle rotation accuracy at different speeds. Studies have shown that when the spindle speed of 10,000 rpm rotational error is small and tends to be more stable. Identify the factors that affect the accuracy of spindle rotation and summarized. Spindle rotation accuracy on-line monitoring and speed control provides an important theoretical, experimental basis.
Abstract: An investigation is reported of the thermal performance of a flat plate solar water heater with a circulating absorber pipe surface. The thermal performance of the 2-side parallel serpentine flow solar water heater depends significantly on the heat transfer rate between the absorber surface and the water, and on the amount of solar radiation incident on the absorber surface. The modified pipe arrangement has a higher characteristic length for convective heat transfer from the absorber to the water, in addition to having more surface area exposed to solar radiation. It means during the operation of water heater, more solar energy is converted into useful heat. However, this modification has reduced the efficiency of the system marginally.
Abstract: The paper also says about practical measuring geometrical deviations by commonly used tools. Also deals with an analysis of geometric deviations, reasons of their generation and provides their brief description. It points at ways and abilities of measuring shape deviations by means of contact and contactless measuring methods and deals with errors which can affect results of measuring. It evaluates and analyses ability of measuring by various devices. It shows a review of individual measured values and thus provides a view of efficiency, simplicity and accuracy of individual measuring devices and measuring methods.
Abstract: Synthetic Aperture Radar recognition is a non-trivial problem. New features of SAR image are proposed. Based on the gradient ratio pattern for each pixel, the Local Gradient Ratio Pattern Histogram is then computed. Next, multi-scale LGRPH is constructed for dimensionality reduction. Finally, the similarity is obtained by utilizing K-L discrepancy to measure the distance of MLGRPH. The proposed method is theoretically proved to be insensitive to speckle noise, and the adaptability to local gradient variation is also discussed. Experimental results show that the proposed approach performs well.
Abstract: This paper puts forward a safety inspection system for the security issues of miners carry contraband under well. This paper give the composition block diagram of the underground millimeter-wave detection system, and design the data acquisition module, present a design scheme and give the work flowchart.
Abstract: Through the analysis of processing 3D point cloud data obtained by laser radar and establishment of the point cloud model to calculate the volume and displacement to monitor the particular scene in accordance with the detection strategy of the dangerous situation, This article wants to develop a set of all-weather, real-time early monitor system, in order to timely risk information publish, reduce the losses caused by disasters. The system uses a modular design approach, which is divided into the information collection module, the information processing module, the analysis of early warning modules and information transmission module. The paper details the system design, and application in the design and implementation of technology and point cloud data processing algorithm. The system use serial programming techniques for laser radar data and control PTZ, and multi-threading technology to improve the efficiency of the serial communication and resolve the problem of multi-serial real-time data collection.