scholarly journals Numerical Approximation of a Compressible Multiphase System

2014 ◽  
Vol 15 (5) ◽  
pp. 1237-1265 ◽  
Author(s):  
Remi Abgrall ◽  
Harish Kumar

AbstractThe numerical simulation of non conservative system is a difficult challenge for two reasons at least. The first one is that it is not possible to derive jump relations directly from conservation principles, so that in general, if the model description is non ambiguous for smooth solutions, this is no longer the case for discontinuous solutions. From the numerical view point, this leads to the following situation: if a scheme is stable, its limit for mesh convergence will depend on its dissipative structure. This is well known since at least [1]. In this paper we are interested in the “dual” problem: given a system in non conservative form and consistent jump relations, how can we construct a numerical scheme that will, for mesh convergence, provide limit solutions that are the exact solution of the problem. In order to investigate this problem, we consider a multiphase flow model for which jump relations are known. Our scheme is an hybridation of Glimm scheme and Roe scheme.

2021 ◽  
Vol 273 ◽  
pp. 05011
Author(s):  
Yulia Semenikhina ◽  
Sergey Kambulov ◽  
Dmitriy Podlesniy ◽  
Tamara Vladimirova ◽  
Sergey Belousov

When cultivating crops in arid conditions, special importance is attached to soil cultivation systems aimed at eliminating the deficiency of soil moisture. The main purpose of soil cultivation is to create an optimal soil structure, which is a multiphase system of solid, liquid and gaseous components that form soil fertility with a subsequent effect on the yield of agricultural crops. Various soil cultivation systems are used to form a favorable soil structure. The conservative cultivation system consists in the minimum impact on the soil (usually direct sowing) and with the preservation of plant residues on its surface. The relevance of the study is to identify the most effective system of soil cultivation. The study was carried out under the conditions of many years of stationary experience in legume crop rotation for 5 years. It was revealed that the conservative system of soil cultivation is effective and surpasses the traditional one in the following indicators: soil moisture is more by 14.2%; the soil temperature is 2.6% lower; soil density is 3.48% higher. A stable increase in yield was also revealed: for winter wheat by 6.62%, for spring barley by 8.09%, for peas by 13.95% and for soybeans by 23.00%.


Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.


2006 ◽  
Vol 34 (1) ◽  
pp. 239-242
Author(s):  
András Makó ◽  
Barbara Elek
Keyword(s):  

2020 ◽  
Vol 20 (3) ◽  
pp. 343-353
Author(s):  
Ngo Van He ◽  
Le Thi Thai

In this paper, a commercial CFD code, ANSYS-Fluent has been used to investigate the effect of mesh number generated in the computed domain on the CFD aerodynamic performances of a container ship. A full-scale model of the 1200TEU container ship has been chosen as a reference model in the computation. Five different mesh numbers for the same dimension domain have been used and the CFD aerodynamic performances of the above water surface hull of the ship have been shown. The obtained CFD results show a remarkable effect of mesh number on aerodynamic performances of the ship and the mesh convergence has been found. The study is an evidence to prove that the mesh number has affected the CFD results in general and the accuracy of the CFD aerodynamic performances in particular.


Tellus B ◽  
2011 ◽  
Vol 63 (4) ◽  
Author(s):  
Bernd Heinold ◽  
Ina Tegen ◽  
Kerstin Schepanski ◽  
Matthias Tesche ◽  
Michael Esselborn ◽  
...  

1988 ◽  
Author(s):  
A. T. Hopkins ◽  
Darrell L. Palmer ◽  
Jeffrey R. Brown

1997 ◽  
Vol 62 ◽  
Author(s):  
R. Samson ◽  
S. Follens ◽  
R. Lemeur

A  multi-layer model (FORUG) was developed, to simulate the canopy  photosynthesis of a mixed deciduous forest during the growing season.  Measured photosynthesis parameters, for beech (Fagus  sylvatica), oak (Quercus  robur) and ash (Fraxinus  excelsior), were used as input to the model. This  information at the leaf level is then scaled up to the level of the canopy,  taking into account the radiation profiles (diffuse and direct PAR) in the  canopy, the vertical LAI distribution, the evolution of the LAI and the  photosynthesis parameters during the growing season, and the temperature  dependence of the latter parameters.


2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Maja Atanasijevic-Kunc ◽  
Joze Dinovec ◽  
Tina Sentocnik
Keyword(s):  

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