Materialien - Allgemein
Refine
Document Type
- Article (2)
Language
- English (2)
Has Fulltext
- yes (2)
Is part of the Bibliography
- yes (2)
Keywords
- Adiabatic block (1)
- Butadien (1)
- Grooved channel (1)
- HSD Publikationsfonds (1)
- Heat transfer augmentation (1)
- Katalyse (1)
- Material (1)
- Mixed convective flow (1)
- Nanofluids (1)
- Neural network (1)
Department/institution
This study investigates heat transfer enhancement in magneto-nanofluidic systems through the strategic placement of adiabatic blocks in grooved channels. Using CuO–H2O nanofluid in a bottom-heated channel with circular expansion, we examine the complex interactions between forced convection, magnetic fields, and uoyancy effects. Through systematic numerical analysis, we explore the combined influences of Rayleigh, Reynolds, and Hartmann numbers on thermal performance. Our findings reveal significant heat transfer enhancement (up to 137 %) under optimal conditions, particularly with vertical magnetic field orientation at Re = 100 and Ha = 30. The results demonstrate how adiabatic blocks modify flow structures, with larger blocks diminishing vortex intensity while elevated Ra generates secondary vortices that interact with primary circulations. Magnetic field effects show notable dependence on orientation, with vertical fields generally promoting better heat transfer than horizontal configurations. To complement the numerical analysis, we develop a predictive model using Artificial Neural Network (ANN) for Nusselt numbers across various operating conditions, achieving over 99 % accuracy. The integrated computational-ANN approach offers significant advancements in optimizing thermal systems in various areas, ranging from electronics cooling to microfluidic devices.
The replacement of fossil fuel processes with renewable pathways is critical to circumvent climate change and environmental risks. A process of interest is the production of 1,3-butadiene (BD), which is primarily derived as a by-product of naphtha steam cracking. A sustainable alternative path involves converting renewable ethanol to BD via the Lebedev process, which requires a catalyst with balanced redox, acidic, and basic sites. Due to the necessity of a multifunctional catalyst, existing materials for this reaction are either comprised of catalyst mixtures or supported catalysts. In this study, we introduce a bulk material, saponite, containing M–O–Si sites, which combine required catalytic sites for the ethanol to BD (ETB) reaction in one material. The product composition in ethanol conversion were strongly dependent on the type of 3d-metal used, while no conclusive correlation between surface properties, conversion, and product composition was observed. Herein, using V-Sap*, we achieved an ethene productivity of 448 gethene kgcat−1 h−1 (74%) at 573.15 K. High acetaldehyde productivity was maintained with Cu-Sap* (466 gAcA kgcat−1 h−1, 49%) at 573.15 K and Zn-Sap (528 gAcA kgcat−1 h−1, 55%) at 723.15 K. Mg-Sap primarily produced ethene but also yielded 10 gBD kgcat−1 h−1 BD at 723.15 K. Higher BD outputs were observed with Ni-Sap (31 gBD kgcat−1 h−1 at 523.15 K) and Mn-Sap* (51 gBD kgcat−1 h−1 at 723.15 K). This underscores the potential of saponite-based materials for flexible product outputs in ethanol conversion, influenced by the choice of integrated 3d-metal.