15 research outputs found
2D FSI determination of mechanical stresses on aneurismal walls
In this study, a fluid-structure interaction analysis based on the application of patient-specific mechanical parameters of the aneurismal walls was carried out to predict the rupture side during an abdominal aortic aneurysm (AAA). Realistic geometry of the aneurysm was reconstructed from CT data acquired from the patient, and patient-specific flow conditions were applied as boundary conditions. A newly developed non-invasive methodology for determining the mechanical parameters of the patient-specific aortic wall was employed to simulate realistic aortic wall behaviors. Analysis
of the results included time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and von Mises stress (VMS). Results of the TAWSS, OSI, and VMS were compared to identify the most probable region of the AAA's rupture. High OSI, which identified the region of wall degradation, coincided with the location of maximum VMS, meaning that the anterior part of the aneurismal wall was a potential region of rupture
Mathematical modeling of moisture evaporation in co-current foam spray drying
[EN] Two models of foam drying are presented in the paper: single droplet drying and perfect mixing of phases spray drying models to describe mechanism of drying of droplet containing bubble. Analysis of drying curves shows that in constant drying rate period and in the falling drying rate period, evaporation rate decreases due to particle shrinkage and increasing of resistance of moisture diffusion inside the solid crust. Increase of gas pressure in the bubble might cause particle breakage. Slight differences between theoretical and experimental results caused by disregarding broken particles in the simulations proves accuracy of the developed model.Jaskulski, M.; Lewandowski, A.; ZbiciĆski, I. (2018). Mathematical modeling of moisture evaporation in co-current foam spray drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat PolitĂšcnica de ValĂšncia. 91-98. https://doi.org/10.4995/IDS2018.2018.7252OCS919
Application of LCA to Determine Environmental Impact of Concentrated Photovoltaic Solar PanelsâState-of-the-Art
Photovoltaic systems represent a leading part of the market in the renewable energies
sector. Contemporary technology offers possibilities to improve systems converting sun energy,
especially for the efficiency of modules. The paper focuses on current concentrated photovoltaic
(CPV) technologies, presenting data for solar cells and modules working under lab conditions as well
as in a real environment. In this paper, we consider up-to-date solutions for two types of concentrating
photovoltaic systems: high-concentration photovoltaics (HCPV) and low-concentration photovoltaics
(LCPV). The current status of CPV solar modules was complemented by the preliminary results
of new hybrid photovoltaic technology achieving records in efficiency. Compared to traditional
Si-PV panels, CPV modules achieve greater conversion efficiency as a result of the concentrator
optics applied. Specific CPV technologies were described in terms of efficiency, new approaches of a
multijunction solar cell, a tracking system, and durability. The results of the analysis prove intensive
development in the field of CPV modules and the potential of achieving record system efficiency. The
paper also presents methods for the determination of the environmental impact of CPV during the
entire life cycle by life cycle assessment (LCA) analysis and possible waste management scenarios.
Environmental performance is generally assessed based on standard indicators, such as energy
payback time, CO2 footprint, or GHG emission
Analysis of factors affecting the ecological status of the large water bodies on the basis of monitoring and integrated 3D models
The paper presents water monitoring methods used to determine and predict the ecological status of large water bodies based on calibrated 3D water quality models. State monitoring system of quality of water was discussed and critically reviewed. Mobile measurements technique to collect vast number of measuring points across the large water body during one day cruise to make maps of pollutants distributions was described. Maps of water quality parameters show dynamic changes of spatial distributions of pollutants both in time and along the length of the lake which proves that one point measurements cannot be representative for the large water body. Critical evaluation of calibration principles and accuracy of the most frequently used water quality models, WASP and GEMSS are presented. On the basis of CFD calculations, close correlation between water quality and hydrodynamics in large water bodies regarding the physicochemical aspects and biological production was proved. Neglecting the effect of hydrodynamic on eutrophication process introduce large element of uncertainty in determination of nutrients flow in the large water bodies. An example of scenarios for improving the ecological potential of dam reservoirs to obtain significant reduction of selected nutrients concentration in the lake is discussed
Analysis of factors affecting the ecological status of the large water bodies on the basis of monitoring and integrated 3D models
The paper presents water monitoring methods used to determine and predict the ecological status of large water bodies based on calibrated 3D water quality models. State monitoring system of quality of water was discussed and critically reviewed. Mobile measurements technique to collect vast number of measuring points across the large water body during one day cruise to make maps of pollutants distributions was described. Maps of water quality parameters show dynamic changes of spatial distributions of pollutants both in time and along the length of the lake which proves that one point measurements cannot be representative for the large water body. Critical evaluation of calibration principles and accuracy of the most frequently used water quality models, WASP and GEMSS are presented. On the basis of CFD calculations, close correlation between water quality and hydrodynamics in large water bodies regarding the physicochemical aspects and biological production was proved. Neglecting the effect of hydrodynamic on eutrophication process introduce large element of uncertainty in determination of nutrients flow in the large water bodies. An example of scenarios for improving the ecological potential of dam reservoirs to obtain significant reduction of selected nutrients concentration in the lake is discussed
Experimental analysis of particle breakage and powder morphology in foam spray drying
[EN] The paper presents results of experiments of gas admixing foam spray drying of maltodextrin in co-current spray tower. Significant effect of feed foaming on particle sphericity, angle of repose, apparent and bulk density, Hausner ratio and porosity was found. Number of broken particles achieved 60 % for high foaming gas rate (GLR) and inlet air temperature due to particle overheating and bubble expansion. Analysis of the experiments results allowed to determine optimal range of operating conditions to reduce number of damaged particles, to around 15 % for the highest GLR and to minimize product degradation.Lewandowski, A.; Jaskulski, M.; ZbiciĆski, I. (2018). Experimental analysis of particle breakage and powder morphology in foam spray drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat PolitĂšcnica de ValĂšncia. 1213-1220. https://doi.org/10.4995/IDS2018.2018.7251OCS1213122
3-D CFD simulations of hydrodynamics in the Sulejow dam reservoir
This paper reports the processes by which a single-phase 3-D CFD model of hydrodynamics in a 17-km-long dam reservoir was developed, verified and tested. A simplified VOF model of flow was elaborated to determine the effect of wind on hydrodynamics in the lake. A hexahedral mesh with over 17 million elements and a k-Ï SST turbulence model were defined for single-phase simulations in steady-state conditions. The model was verified on the basis of the extensive flow measurements (StreamPro ADCP, USA). Excellent agreement (average error of less than 10%) between computed and measured velocity profiles was found. The simulation results proved a strong effect of wind on hydrodynamics in the lake, especially on the development of the water circulation pattern in the lacustrine zone
Effect of replacement of tin doped indium oxide (ITO) by ZnO: analysis of environmental impact categories
Abundant use of natural resources is doubtlessly one of the greatest challenges of sustainable development. Process alternatives, which enable sustainable manufacturing of valuable products from more accessible resources, are consequently required. One of examples of limited resources is Indium, currently broadly used for tin doped indium oxide (ITO) for production of transparent conductive films (TCO) in electronics industry. Therefore, candidates for Indium replacement, which would offer as good performance as the industrial state-of-the-art technology based on ITO are widely studied. However, the environmental impact of new layers remains unknown. Hence, this paper studies the environmental effect of ITO replacement by zinc oxide (ZnO) by means life cycle assessment (LCA) methodology. The analysis enables to quantify the environmental impact over the entire period of life cycle of productsâduring manufacturing, use phase and waste generation. The analysis was based on experimental data for deposition process. Further, analysis of different impact categories was performed in order to determine specific environmental effects related to technology change. What results from the analysis, is that ZnO is a robust alternative material for ITO replacement regarding environmental load and energy efficiency of deposition process which is also crucial for sustainable TCO layer production
Effect of replacement of tin doped indium oxide (ITO) by ZnO: analysis of environmental impact categories
Abundant use of natural resources is doubtlessly one of the greatest challenges of sustainable development. Process alternatives, which enable sustainable manufacturing of valuable products from more accessible resources, are consequently required. One of examples of limited resources is Indium, currently broadly used for tin doped indium oxide (ITO) for production of transparent conductive films (TCO) in electronics industry. Therefore, candidates for Indium replacement, which would offer as good performance as the industrial state-of-the-art technology based on ITO are widely studied. However, the environmental impact of new layers remains unknown. Hence, this paper studies the environmental effect of ITO replacement by zinc oxide (ZnO) by means life cycle assessment (LCA) methodology. The analysis enables to quantify the environmental impact over the entire period of life cycle of productsâduring manufacturing, use phase and waste generation. The analysis was based on experimental data for deposition process. Further, analysis of different impact categories was performed in order to determine specific environmental effects related to technology change. What results from the analysis, is that ZnO is a robust alternative material for ITO replacement regarding environmental load and energy efficiency of deposition process which is also crucial for sustainable TCO layer production