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91.
Implicit large eddy simulation using the high‐order correction procedure via reconstruction scheme
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We investigate implicit large eddy simulation of the Taylor–Green vortex, Comte‐Bellot–Corrsin experiment, turbulent channel flow and transitional and turbulent flow over an SD7003 airfoil using the high‐order unstructured correction procedure via reconstruction (CPR) scheme, also known as the flux reconstruction scheme. We employ P1 (second‐order) to P5 (sixth‐order) spatial discretizations. Results show that the CPR scheme can accurately predict turbulent flows without the addition of a sub‐grid scale model. Numerical dissipation, concentrated at the smallest resolved scales, is found to filter high‐frequency content from the solution. In addition, the high‐order schemes are found to be more accurate than the low‐order schemes on a per degree of freedom basis for the canonical test cases we consider. These results motivate the further investigation and use of the CPR scheme for simulating turbulent flows. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
92.
93.
Alla Siva Reddy Prof. K. C. Kumara Swamy 《Angewandte Chemie (International ed. in English)》2017,56(24):6984-6988
Ethanol is shown to act as a hydrogenating agent for ynamides under palladium catalysis. This behavior is different from the normally expected reaction of ethanol addition to alkynes. The reaction shows stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources. The method was also extended to ynamines. Alternatively, the use of ethanol and ammonium formate as the hydrogenating source gives Z enamides. The role of ethanol in hydrogenation was demonstrated by means deuterium labeling experiment. 相似文献
94.
Kung-Kai Kuo Siva Senthil Kumar Boominathan Jaya Kishore Vandavasi Jia-Shing Hsiao Jeh-Jeng Wang 《合成通讯》2016,46(19):1612-1618
A new one-pot synthetic methodology has been developed to construct the triazole-linked urea derivatives. In the same step, triazole forms from azide and alkyne via click reaction and urea forms from addition reaction of amines and isocyanates. The notable features of this work include wide substrate scope, atom economy, environmental friendliness, and easily accessible starting materials. The preliminary biological screening of synthesized compounds show promising cytotoxic activity in basal cell carcinoma (BCC) cell lines. 相似文献
95.
Singh Sahjendra N. Myatt James H. Addington Gregory A. Banda Siva S. Hall James K. 《Nonlinear dynamics》2002,28(1):71-81
This paper treats the question of feedback linearizing control oftwo-dimensional incompressible, unsteady wake flow. For definiteness,flow past a circular cylinder is considered, but the design approachpresented here is applicable to other flow control problems. Twofinite-dimensional lower-order models based on Proper OrthogonalDecomposition (POD) of dimension N with N actuators are considered.Models I and II are obtained using control function and penalty functionmethods, respectively. Control action can be achieved by a combinationof suction, injection, and synthetic jets. For the design ofcontrollers, it is assumed that the system matrices of the POD modelsare unknown. Nonlinear adaptive control systems for the two models arederived. For model I, nontrivial zero-error dynamics exists, which playa key role in the stability of the closed-loop system. But for model II,global adaptive trajectory control is achieved. In the closed-loopsystem, the mode amplitudes asymptotically follow the referencetrajectories. Simulation results for a 4-mode POD model obtained usingthe penalty function method are presented. These results show that inthe closed-loop system, unsteadiness in the mode amplitudes can besuppressed in spite of large uncertainties in the flow model. 相似文献
96.
S. Siva Nasarayya Chari Ramarao Inguva K. P. N. Murthy 《Journal of statistical physics》2014,157(1):113-123
The first equation of the BBGKY hierarchy is closed with a truncation scheme which conserves mass, momentum and total energy. Resulting kinetic equation is solved numerically using the lattice Boltzmann method over an isothermal \(D2Q9\) lattice. The inter particle forces are derived using a density gradient approximation to the collision term of the BBGKY hierarchy and the resulting non-ideal equation of state is calculated. In this paper, we show analytically that the time rate of change of Boltzmann’s H-function i.e., \(\frac{dH \left( t \right) }{dt}\) is zero for this truncation scheme, implying reversibility in time. Therefore, a BGK term is added to the collision integral to describe the macroscopic irreversibility. Both the local and global \(H\) -functions are calculated numerically for significant variations in the density. We also have simulated a switching experiment over this system and obtained the non-equilibrium work distributions. 相似文献
97.
N. Siva Raman K. K. Sivagnana Prabhu R. Kandasamy 《Journal of Engineering Thermophysics》2014,23(1):66-78
The objective of the present work is to investigate theoretically the Hiemenz flow and heat transfer of an incompressible viscous nanofluid past a porous wedge sheet in the presence of suction/injection due to solar energy (incident radiation). The wall of the wedge is embedded in a uniform Darcian porous medium in order to allow for possible fluid wall suction or injection and has a power-law variation of the wall temperature. The partial differential equations governing the problem under consideration are transformed by a special form of Lie symmetry group transformations viz. one-parameter group of transformation into a system of ordinary differential equations, which are solved numerically using Runge-Kutta-Gill based shooting method. The conclusion is drawn that the flow field and temperature are significantly influenced by thermal radiation, nanoparticle volume fraction, and porosity of the sheet. 相似文献
98.
Siva S. Panda 《合成通讯》2013,43(5):729-735
A simple and efficient procedure for the synthesis of 2-arylbenzimidazoles through a one-pot condensation of o-phenylenediamines with aryl aldehydes in water is described. Short reaction time, large-scale synthesis, easy and quick isolation of the product, and excellent yield are the main advantages of this procedure. 相似文献
99.
R. Kishore Kumar K. Siva Kumar N. V. V. Jyothi J. Rajasekhar P. Venkateswarlu 《Journal of Analytical Chemistry》2013,68(5):403-408
An enrichment separation procedure for the atomic absorption spectrophotometric determinations of Cu(II) and Ni(II) ions in common edible fishes was established. The 2-[(2-hydroxynaphthalen-1-yl)diazenyl]-5-methylbenzene-1,3-diol (HNDMD) complexes of the analyte ions at pH 6.0 were adsorbed on the p-octylpolyethylene glycolphenylether (Triton X-100) column and then desorbed with 10 mL of acetone. Under optimized conditions, the recovery values were above 95%. The developed preconcentration methods were successfully applied to the determination of Cu(II) and Ni(II) ion concentrations in common edible fishes from the local market. The precision and accuracy of the method are very good. 相似文献
100.
E. Rajanarendar P. Ramesh E. Kalyan Rao A. Siva Rami Reddy 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2555-2564
Isoxazolyl chloroacetamides (2) were obtained from 4-amino-3-methyl-5-styrylisoxazoles (1) on reaction with chloroacetyl chloride. Cyclocondensation of 2 with NH4SCN yielded 2([-methyl-5-(E)-2-aryl-1-ethenyl]-4-isoxazolylimino)-1,3-thiazolan-4-ones(3). Mannich reaction of 3 with formaldehyde and secondary amines gave isoxazolyl thiazolidinone Mannich bases (4 and 5). 相似文献