Advanced Materials Research Vols. 881-883

Abstract: Computational Fluid Dynamics (CFD) simulation is expected to give detailed flow information which is important for stirred reactor design and optimization, however accurate flow prediction remains a challenge for CFD application. In the present paper, influence of discretization scheme on the flow prediction in a stirred reactor with Rushton turbine was investigated. Standard k-ε turbulent model and MRF model was adopted and numerical results obtained by using three different discretization schemes were compared. Results showed that the numerical results agreed well with data provided in literature. It is acceptable to use any discreticaiton method if aiming at a general flow field, while QUICK is recommended considering the more detailed flow information.

Abstract: In fuel-fired power plants, error resulting from test process of copper content should be decreased to minimum because trace copper is in the steam-water. 100μg/mL copper reference solution is prepared in the laboratory and its concentration is determined by means of EDTA compleximetry. Then the uncertainty is analyzed and calculated from every factor. The result shows that the expanded uncertainty of 100μg/mL copper reference solution is 0.6μg/mL.

Abstract: In this paper, an improved coaxial measurement system with a newly designed coaxial fixture is presented. The electromagnetic parameters of samples are retrieved from the scattering parameters measured by a vector network analyzer (VNA) at microwave frequencies. The measurements of air and PTFE in the range of 1~6 GHz were carried out to verify the reliability and the accuracy of this measurement system. By using frequency-sweep and data processing techniques, the multiplicity of roots is eliminated. The results show that this system can effectively be applied to measure the material electromagnetic parameters of absorbing materials with high accuracy in a wide frequency band.

Abstract: It was found from the experiment that the high temperature caused by target impact led to projectile austenite phase transformation. Based on this finding, a phase transformation model was established and verified by experiments, which proved the model had a relatively high calculation precision. Then, the model was used for numerical simulation. The result showed that the phase transformation zone was at the projectile head surface and the area increased as the impact velocity increased. The critical impact velocity which would cause phase transformation and affect projectile performance was around 700m/s.

Abstract: It introduced the depth-sensing indentation principle,characteristics,and the major applications and advantages in micromechanical properties and damage research. It focused on analyzing the typical load-depth test curve from the material depth-sensing indentation experiment, then talked about how the curve was used in the reverse calculation process for material mechanics properties.It can provide the technology route reference for the other metal mechanical properties research in the future.

Abstract: Using the Renka Cline algorithm provided by OriginPro8.6 to fit the longitudinal residual stress through parts of the measurement value on the A7N01-T5 aluminum alloy butt welded joints compared with the whole measurement value. The result shows that the fitting value approximates the measurement value. The fitting value is reliable. So, Renka Cline algorithm is a reliable method to analyze the longitudinal residual stress on a plate region.