In the present investigation, a computational fluid dynamics technique is used to investigate the ventilated supercavitation reaction to the change of gas supply rate. Detached eddy simulation, a hybrid RANS-LES method is used for turbulence modeling, and improved Singhal’s model is used to simulate cavitation process. Simulation results show that the change of cavity shape is lagging behind that of gas supply. When gas supply is shut, cavities experience a series fluctuation before reaching equilibrium state, if natural cavitation numbers are large; in contrast, they are monotone decreasing under small natural cavitation numbers.

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A diagnosis of corrosion failure in steel wire ropes based on wavelet and support vector machine (SVM) is investigated. Wavelet decomposition and reconstruction algorithm is used to denoise the magnetic flux leakage (MFL) signals, then peak value, trough value, peak-to-peak value and energy parameters are extracted as fault feature vectors, and a SVM classifier is designed and used to conduct the fault pattern recognition. The experimental results show that the accuracy of the SVM classification achieves to 100%.

A typical hybrid RANS-LES approach, DES (Detached Eddy Simulation), was introduced into cavitating flow simulation in this paper. The applicability of two DES models, including one equation DES model and SST k-ω DES model, and standard k-ε model was analyzed through experimental data of a water tunnel experiment. Validation results illustrate that the precision of DES method depends on the RANS model used and the length scale used to distinguish LES zone and RANS zone. The SST k-ω DES method can well predict cavitating flow. The averaged results gained through this model are better than those of standard k-ε or one equation DES model. By comparison, the one equation DES model shows little advantage than standard k-ε model to simulate cavitating flow.

Sol-gel tequnique was used to prepare disordered tungsten oxide and molybdenum oxide sols. A series ratio of W:Mo compound sols were obtained via mettalic powder co-peroxided by H2O2 as precursors in ethonal. Compound films were achieved by dip-coating method. Fourier Transform Infrared Spectroscopy, Raman Spectroscopy were taken to characterize the structure of these compound films. Uv-visible Spectroscopy was used to test the gasochromic property. The results showed that the gasochromics property was much different from that of pure tungsten oxide and molybdenum oxide sol-gel thin films. The effect was origined from the structrue alteration, which was not due to the spectrum superposition but the co-reaction of W and Mo.