scholarly journals Modeling Separation Process for Sunflower Seed Mixture on Vibro-Pneumatic Separators

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 311-320
Author(s):  
Igor SHEVCHENKO ◽  
Elchyn ALIIEV ◽  
Gintas VISELGA ◽  
Jan Radek KAMINSKI

Aim of the research is to increase the efficiency of the mechanical and technological process of separation of sunflower seed mixture on vibro-pneumatic separators, the principle of which is based on the interaction of seed flow with the surface having fluctuation-type vibration load by substantiating their efficient processing and technological parameters. A system of differential equations of sunflower seeds motions, as a granular gas, under the action of a vibrating surface was developed, taking into account the elastic-damping interaction and physical and mechanical properties of seeds. The presented system of differential equations is the basis of the physical and mathematical means of numerical modeling of this process, which was implemented in the software package STAR-CCM +. To build physical and mathematical models, it was assumed that sunflower seeds are presented in the form of ellipsoids with a certain density and effective diameter. As a result of numerical simulation of the process of moving sunflower seeds under the action of a vibrating sieve, dependences of the change in total concentration θ and productivity q on seed supply Q, sieve angle α, sieve frequency ψ and sieve amplitude A were obtained. As a result of numerical simulation of the process of moving sunflower seeds under the action of a vibrating surface, dependences of the change of filling factor χ, distribution coefficient δ and productivity q on seed supply Q, vibration surface angles α and β, oscillation frequency ψ, oscillation amplitude A and set air velocity V were obtained. Theoretical provisions were implemented and tested in the development of an adaptive vibrating screen separator of sunflower seeds (Ukrainian patent #120235).

2004 ◽  
Vol 22 (4) ◽  
pp. 451-459 ◽  
Author(s):  
YVES SAILLARD

The system of differential equations for the non-ablated mass, the average implosion velocity, and the ablation radius of an indirectly driven capsule in acceleration phase, has been obtained from conservation principles of hydrodynamics. Two phases are distinguished during acceleration, according to the uniformity of the velocity in the non-ablated shell. The results of the integration of this system are well compared with numerical simulation of optimized capsules. Assuming that the ablation pressure depends only on the Hohlraum temperature, the relations between the non-ablated mass, the implosion velocity, and the ablation radius are obtained for optimized temperature shape. These relations provide the maximum implosion velocity and the remaining non-ablated mass in terms of the initial capsule and the maximum temperature (or the initial capsule mass in terms of the remaining non-ablated mass) useful to determine the required ablator thickness for optimized capsules. These results are also compared with numerical simulations of different capsules.


Author(s):  
Arif Muchyidin

Batik as an Indonesian national identity has contributed greatly to the Indonesian economy. However, the value of exports and other economic potentials are not supported by the number of batik, especially batik artisans in the village Trusmi. Trusmi batik artisans in the village is a craftsman who has been there all the time and remain there for generations. The phenomenon that occurs in the craft of batik Trusmi analyzed with mathematical modeling approach, in this case the dynamical system. From the resulting system of differential equations, then analyzed the stability around the critical point. From the resulting model, gained two critical points. The first critical point is a condition where there is no proficient craftmen (not expected), whereas at the second critical point is the potential of batik craftmen and proficient craftmen mutually exist, or in other words batik will still exist. From the results of numerical simulation, if , then batik Trusmi will still exist. However, if , then the number of proficient craftmen would quickly dwindle and slowly batik will be extinct.Key Words : dinamical system, critical points, stability


2018 ◽  
Vol 09 (04) ◽  
pp. 1850008
Author(s):  
OPhir Nave

In this paper, we apply a new algorithm called method of directly defining the inverse mapping (MDDiM) that was introduced by Liao for finding a semi-analytical solution to nonlinear system of differential equations. We apply this new method to the autoignition of a monodisperse fuel spray model. We use this technique for finding the base functions in the considered algorithm. Our results include a comparison between a numerical simulation and an analytical solutions derived from the MDDiM.


Author(s):  
Arif Muchyidin

Batik as an Indonesian national identity has contributed greatly to the Indonesian economy. However, the value of exports and other economic potentials are not supported by the number of batik, especially batik artisans in the village Trusmi. Trusmi batik artisans in the village is a craftsman who has been there all the time and remain there for generations. The phenomenon that occurs in the craft of batik Trusmi analyzed with mathematical modeling approach, in this case the dynamical system. From the resulting system of differential equations, then analyzed the stability around the critical point. From the resulting model, gained two critical points. The first critical point is a condition where there is no proficient craftmen (not expected), whereas at the second critical point is the potential of batik craftmen and proficient craftmen mutually exist, or in other words batik will still exist. From the results of numerical simulation, if , then batik Trusmi will still exist. However, if , then the number of proficient craftmen would quickly dwindle and slowly batik will be extinct.Key Words : dinamical system, critical points, stability


1998 ◽  
Vol 11 (1) ◽  
pp. 381-381
Author(s):  
A.V. Dorodnitsyn

We have considered a stationary outflowing envelope accelerated by the radiative force in arbitrary optical depth case. Introduced approximations provide satisfactory description of the behavior of the matter flux with partially separated radiation at arbitrary optical depths. The obtained systemof differential equations provides a continuous transition of the solution between optically thin and optically thick regions. We analytically derivedapproximate representation of the solution at the vicinity of the sonic point. Using this representation we numerically integrate the system of equations from the critical point to the infinity. Matching the boundary conditions we obtain solutions describing the problem system of differential equations. The theoretical approach advanced in this work could be useful for self-consistent simulations of massive star evolution with mass loss.


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