Browsing by Subject "computational fluid dynamics"

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Access status: Open Access ,
A numerical simulation study of mold filling in the injection molding process
(Wydawnictwa AGH, 2021) Baum, Markus; Anders, Denis
Injection molding can undoubtedly be regarded as one of the most widely used manufacturing processes for polymers (Guevara-Morales & Figueroa-Lopez, 2014). Furthermore, injection molding has found its way into various branches of industry (Fernandez et al., 2018) since it has several essential advantages over other processing techniques in terms of good surface finish, the ability to process complex parts without the need for secondary operations, and low cost for mass production. In order to find optimal process settings, it is necessary to gain a deeper insight into the filling process and the underlying physical phenomena, as well as a thorough understanding of the complex material behavior. In this context, the numerical simulation of the injection molding process is increasingly important. Therefore, the current contribution is dedicated to present a thorough comparative numerical study for the mold filling of an exemplary thin-walled mold geometry, including a realistic non-Newtonian viscosity model for the polymer melt. For the numerical simulation, the authors employ the commercial CFD software packages Cadmould 3D-F and ANSYS CFX. While ANSYS CFX is a well-established CFD software for numerical modelling of multiphysical phenomena, Cadmould 3D-F is a highly specialized and computationally efficient alternative suitable for certain geometric configurations in the context of injection molding. The present study is new in the sense that it demonstrates the equivalence of the considered software packages for the simulation of the injection molding process in thin-walled mold geometries.
Access status: Restricted ,
Eksperymentalne i numeryczne określanie charakterystyk wentylatora promieniowego transportującego powietrze do przestrzeni nieograniczonej
(Data obrony: 2015-07-20) Gorzała, Paweł
Wydział Energetyki i Paliw
Access status: Open Access ,
Fast pyrolysis of agricultural biomass in drop tube reactor for bio-oil production: Numerical calculations
(2023) Bieniek, Artur; Sieradzka, Małgorzata; Jerzak, Wojciech; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej
Fast biomass pyrolysis is an effective method for bio-oil production and can be performed in fluidised beds, augers, and drop-tube reactors. In this study, the fast pyrolysis of agricultural biomass (oat and corn straw) in a drop-tube reactor was investigated by applying multiparameter analysis involving numerical calculations. The main motivation for this analysis was to determine the operating parameters for fast pyrolysis under which the highest bio-oil production was achieved. In this study, the following operating parameters were involved: pyrolysis temperature (500 – 700 ◦C), volume flow rate of the carrier gas (3 – 5 l/min), mass flow rate of the feedstock (10 – 30 g/h), and diameter of the particle (250 – 750 μm). The analysis was performed using numerical methods with the Euler-Lagrange multiphase theory in a 2D axisymmetric model. According to the numerical results, selection of a particle size of 500 μm, pyrolysis temperature of 500 ◦C, and nitrogen flow rate of 3 l/min allows obtaining 51.16% and 52.09% of bio-oil for oat straw and corn straw pyrolysis, respectively. The biomass mass load did not influence the final product yield. The numerical results were successfully confirmed by experimental investigations where experiments supplied 53.2% and 51.3% of bio-oil to oat straw and corn straw, respectively.
Access status: Open Access ,
Pinch mode magnetorheological flow bench: fluid flow analysis
(2023) Gołdasz, Janusz; Sapiński, Bogdan; Kubik, Michał; Machacek, Ondras; Bańkosz, Wojciech
Wydział Inżynierii Mechanicznej i Robotyki
Magnetorheological (MR) fluids are known smart materials. In the presence of magnetic field the material develops a yield stress. The technology has been used in the automotive industry, for example, or high quality optical finishing applications. In the (existing) conventional flow-mode valves the MR fluid is energized by magnetic flux perpendicular to the fluid flow path. The effect is an increase in the material’s effective resistance-to-flow. The so-called gradient pinch mode (GPM) follows a different principle – the flux in the flow channel is directed to activate the fluid in the areas adjacent to the channel walls. Then, high yield stresses are induced in the material in the adjacent zones and low yield stresses are achieved in the middle of the channel, the yield stress distribution is non-uniform. As a result, a Venturi-like contraction is formed solely by material means, i.e. without changing the flow path geometry. This may lead to a new category of controlled semi-active valves. However, a fundamental research is still required to characterize the rheology of MR fluids in this mode. In the study the authors explore opportunities for building a pinch mode valve assembly for the experimental work with MR fluids. The authors propose a solenoid assembly that can be integrated into a flow bench, and then proceed with a CFD steady-state study of the fluid flow through the valve. The results are then presented in the form of velocity plots and pressure maps as well as averaged pressure drop vs volumetric flow rate, respectively, at various levels of ampere turns.
Access status: Restricted ,
Projekt wentylatora promieniowego w obudowie spiralnej
(Data obrony: 2015-10-26) Kleszcz, Sławosz
Wydział Energetyki i Paliw