CFD simulation analysis of two-dimensional convergent-divergent nozzle

ABSTRACT

Computational fluid dynamics is one of the parts of fluid mechanics and calculating numerical methods are solving the various flows of fluid. Two-dimensional models, which is to solve the flow rate of supersonic flow and analyzed the mathematical operations, which has solved the energy equations. This iteration process has analyzed and shown better results of temperature and static pressure, velocity, static temperature. The investigating results showing better temperature and velocity flows. The 2D nozzle line diagram is done in Ansys 14.5 geometry modular and calculated iteration process can be done in fluid flow. The nozzle is done and meshes using automatic method and sizing of different value of the meshing process. In the order to analyzed the Ansys fluent software and solved the flow process of the convergent-divergent iteration nozzle. Standard nozzle equation manually calculated and compared with analyzing the results.     

TeCSMART: A hierarchical framework for modeling and analyzing systemic risk in sociotechnical systems

Recent systemic failures in different domains continue to remind us of the fragility of complex sociotechnical systems. Although these failures occurred in different domains, there are common failure mechanisms that often underlie such events. Hence, it is important to study these disasters from a unifying systems engineering perspective so that one can understand the commonalities as well as the differences to prevent or mitigate future events. A new conceptual framework that systematically identifies the failure mechanisms in a sociotechnical system, across different domains is proposed. Our analysis includes multiple levels of a system, both social and technical, and identifies the potential failure modes of equipment, humans, policies, and institutions. With the aid of three major recent disasters, how this framework could help us compare systemic failures in different domains and identify the common failure mechanisms at all levels of the system is demonstrated. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3065–3084, 2016     

Thermopower of Mesoscopic Normal-metal/Superconductor Heterostructures

Measurements of micron-size doubly connected normal-Metal/superconductor (NS) heterostructures show athermoelectric response which oscillates as a function ofmagnetic field, with a fundamental period corresponding to oneflux quantum h/2e through the area of the loop. Theoscillations of the thermopower are either symmetric orantisymmetric with respect to magnetic field, depending on thetopology of the sample. The temperature dependence of theamplitude of the oscillations shows a minimum at a temperatureof 0.14 K, although this nonmonotonic behavior doesnot appear to be related to the reentrance effect recentlyobserved in the electrical transport properties of NSstructures.     

Fluorescence study of protein immobilization on poly(4-hydroxyphenyl thiophene-3-carboxylate)-coated electrodes

Synthesis of poly(4-hydroxyphenyl thiophene-3-carboxylate) (PHPT) was carried out in acetonitrile(ACN)/TBAClO₄(0.05 M) solvent-electrolyte medium using different working electrodes (glassy carbon and ITO) via potentiodynamic electrolysis. Characterization of the resulting polymer was performed using cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscopy (AFM) and fluorescence microscopy (FS). The polymer exhibits well-defined and reversible redox behavior in an organic solvent. Flourescence microscopy indicates that protein immobilizes better onto the surface of PHPT-modified electrodes than onto those without such modification.     

Characterisation of CFRP Through Enhanced Ultrasonic Testing Methods

Carbon fibre reinforced composite materials enjoy an increasing field of application in the aeronautical environment and are due to expand into the automotive and leisure sectors in due course. Those materials need to be qualified at reasonable cost and with considerable experience, where ultrasonic testing has become the procedure of primary choice for nondestructive testing (NDT) so far. However, the two-phase anisotropic structure of a composite material implies a variety of challenges such as scattering, beam skewing, and sound field distortion complicating the localization, sizing, and characterization of defects. Besides qualification during the manufacturing stage, additional tasks emerge once the composite material ages, maybe by mechanical fatigue, chemical ageing, or irradiation. Again characterisation of the material based on ultrasonics would allow comparisons to be made along a material??s life cycle. The knowledge generated could be used for in-situ monitoring procedures such as considered in the context of structural health monitoring (SHM).     

Cellular and in vitro toxicity of nanodiamond-polyaniline composites in mammalian and bacterial cell

The composite nanodiamond (ND) particles are rapidly emerging as promising material for the next generation agent for drug delivery, biosensors, or imaging contrast applications. Consequently, the health risks associated with the exposure to nanocomposite materials are utmost important. The objective of our work is to study the toxic effects of the nanodiamond-polyaniline (ND-Pani) composites in Human Embryonic Kidney (HEK) cell line. Toxic effects of either ND or ND-Pani nanocomposite in powder form on HEK293 are tested using MTT assay. Results indicated that there was no significant difference in the cell survival between samples treated with ND-Pani nanocomposite and the control sample for the two lower concentrations used in the experiments (p < 0.05). Morphology of the cells was not significantly affected due to the inclusion of nanocomposites during the incubation phase. The stability of the film was also improved due to the inclusion of the nanodiamond particles into the polymeric matrix making it suitable for electrochemical sensing applications. Experimental results have shown that the toxicity effect of lower concentration of ND-Pani composite is negligible, thus indicating that below 1 μg/ml could be a safer range without secondary toxicity effect.     

Deep Oxidation of Benzene on Pt/V2O5–TiO2 Catalysts

The combustion of benzene was studied on Pt supported on V₂O₅–TiO₂ samples containing different amounts of V₂O₅. Vanadium was highly dispersed as V⁴⁺ for low V₂O₅ loadings, forming a vanadia monolayer on titanium dioxide for a V₂O₅ concentration of about 5%wt. V₂O₅–TiO₂ samples were more active than V₂O₅ and TiO₂ single oxides, and the activity increased with the vanadia content. The platinum dispersion in Pt/V₂O₅–TiO₂ catalysts increased with the V₂O₅ loading but the activity for the deep oxidation of benzene exhibited an opposite trend. Benzene combustion was a structure sensitivity reaction promoted on larger metallic Pt crystallites which were preferentially formed when the V₂O₅ content in the sample was decreased.