Heat transfer enhancement in turbulent upward flows of liquid-solid suspensions through vertical annuli

2001-09-01
Ozbelge, TA
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
189
views
0
downloads
This paper aims to explain the effects of radial solid concentration distributions (RSCDs) [T.A. Ozbelge, A. Beyaz, Dilute solid-liquid upward flows through a vertical annulus in a closed-loop system, Int. J. Multiphase Flow (in press); T.A. Ozbelge, A. Beyaz, Seyreltik Sivi-Kati Karisimlarinin AkiS Ozellikleri, TUBITAK Project INTAG-822, Report No: 196 I 010, Ankara, 1999] on the mechanism of heat transfer enhancement achieved in water-feldspar upward flows [T.A. Ozbelge, S.H. Koker, Int. J. Heat Mass Transfer 39 (1) (1996) 135] through vertical annuli having different aspect ratios (kappa = 0.31, 0.42 and 0.54) at different operating conditions. The increasing trend of local solid concentrations from the inner wall to the outer wall of the annulus [Ozbelge and Beyaz (loc. cit.), Ozbelge et al. (loc. cit.)] is found to be favorable for the enhancement of heat transfer, since the heat transfer between the hot and the cold streams occurs across the inner wall [Ozbelge and Koker (loc. cit.)]. Also, the applicability of the fluid-particle interaction model [C.A. Brandon, D.G. Thomas, in: Proceedings of the Fourth International Heat Transfer Conference, Paris, Paper CT-2.1, 1970] to turbulent liquid-solid flows in the vertical annuli [Ozbelge and Koker (loc. cit.)] is checked here. The location of peak heat transfer enhancement is determined at the dimensionless grouping of d(p)(*) = (d(p)/D-h)(Re-s)(11/16) = 4.2 for water-feldspar slurries flowing turbulently upward in the vertical annuli which is the same value as that obtained in horizontal pipes [T.A. Ozbelge, Int. J. Multiphase Flow 19 (3) (1993) 535], regardless of the geometry. This is in accordance with the interaction model [Brandon and Thomas (loc. cit.); Ozbelge (loc. cit.)].
Pipe
https://hdl.handle.net/11511/63822
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
Department of Chemical Engineering, Article

Suggestions

Investigating the effects of operational parameters on photofermentation in batch and semi-batch reactors and the applications of photofermentation in multi-stage energy systems
Akman, Melih Can; Bayramoğlu, Tuba Hande; Gündüz, Ufuk; Department of Environmental Engineering (2018)
The aim of this thesis study was to investigate the effects of operational parameters on photofermentation in batch and semi-batch reactors, and the application of photofermentation in multi-stage energy systems. Firstly, three operational conditions of the substrate concentration, Volatile Suspended Solids (VSS) concentration and the light intensity leading to the maximization of hydrogen production in a single stage were optimized. The highest hydrogen production rate (HPR) of 1.04 mmol H2/L.h was achieve...
Design criteria for transparent single-wall carbon nanotube thin-film transistors
Ünalan, Hüsnü Emrah; Kanwal, A; Du Pasquier, A; Chhowalla, M (2006-04-01)
A study based on two-dimensional percolation theory yielding quantitative parameters for optimum connectivity of transparent single-wall carbon nanotube (SWNT) thin films is reported. Optimum SWNT concentration in the filtrated solution was found to be 0.1 mg/L with a volume of 30 mL. Such parameters lead to SWNT fractions in the films of approximately Phi = 1.8 x 10(-3), much below the metallic percolation threshold, which is found to be similar to Phi(c) = 5.5 x 10(-3). Therefore, the performance of trans...
Immobilization of glucose oxidase and urease in hydrogel matrices
Gurel, I; Arica, MY; Hasırcı, Vasıf Nejat (1997-01-01)
Immobilization of glucose oxidase and urease in hydrogels of 2-hydroxyethyl methacrylae, and N-vinyl pyrrolidone (NVP) was achieved by irradiation (using UV kand gamma-rays). The effect of radiation on entrapment efficiencies, retention of activities and swelling rates was obtained. To optimize the system, duration of exposure, reaction temperature, co-monomer concentrations, initiator and cross linker compositions were varied. The repeated reusability of the generated products was also tested. It was found...
Application of spring analogy mesh deformation technique in airfoil design optimization
Yang, Yosheph; Özgen, Serkan; Department of Aerospace Engineering (2015)
In this thesis, an airfoil design optimization with Computational Fluid Dynamics (CFD) analysis combined with mesh deformation method is elaborated in detail. The mesh deformation technique is conducted based on spring analogy method. Several improvements and modifications are addressed during the implementation of this method. These enhancements are made so that good quality of the mesh can still be maintained and robustness of the solution can be achieved. The capability of mesh deformation is verified by...
Application of a natural-resonance based feature extraction technique to small-scale aircraft wires for electromagnetic target classification
Ersoy, Mehmet Okan; Sayan, Gönül; Department of Electrical and Electronics Engineering (2004)
The problem studied in this thesis, is the classification of the small-scale aircraft targets by using a natural resonance based electromagnetic feature extraction technique. The aircraft targets are modeled by perfectly conducting, thin wire structures. The electromagnetic back-scattered data used in the classification process, are numerically generated for five aircraft models. A contemporary signal processing tool, the Wigner-Ville distribution is employed in this study in addition to using the principal...
Citation Formats
T. Ozbelge, “Heat transfer enhancement in turbulent upward flows of liquid-solid suspensions through vertical annuli,” INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, pp. 3373–3379, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/63822.
METU IIS - Integrated Information Service open@metu.edu.tr