Flow models for twisted tube heat exchangers

2017 ◽  
Author(s):  
Boris V. Dzyubenko ◽  
Guenrikh A. Dreitser
2020 ◽  
Vol 1448 ◽  
pp. 012010
Author(s):  
J G Ardila M ◽  
M Valdes ◽  
M R Cabal ◽  
A Castro ◽  
J G Quintero

2014 ◽  
Vol 1008-1009 ◽  
pp. 910-913
Author(s):  
Mei Jin ◽  
Li Zhan ◽  
Guo Xian Yu ◽  
Jian Qi Zhang ◽  
Hong Jiao Liu

The effect of the volumetric flow rate on the heat transfer of shell and tube heat exchangers was investigated. Furthermore, a comparison of four flow models using for numerical simulation was discussed to provide improved predictions of turbulent flow in the shell and tube heat exchangers. Four flow models tested were Reynolds stress model, k-ε Standard model, k-ε RNG model and k-ε Realizable model, respectively. Multi reference frame technique was used with Fluent software package. During the numerical simulation, the heat dissipation was shown to be strongly dependent on the choice of turbulence model. Compared with the cold model experimental result, k-ε RNG model was a better turbulence model for the prediction of the heat dissipation in the shell and tube heat exchangers among the four models. Furthermore, the good agreement between the numerical results and the experimental result confirmed the validity of the numerical method.


2017 ◽  
Author(s):  
Boris V. Dzyubenko ◽  
Guenrikh A. Dreitser
Keyword(s):  

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
D. Gomse ◽  
T. M. Kochenburger ◽  
S. Grohmann

Heat exchangers are important components in many engineering applications. This paper proposes a numerical two-phase heat exchanger model with simultaneous heat transfer and pressure drop calculations. The presented model provides a modeling framework compatible with numerous different correlations for both single- and two-phase flow of pure fluids and fluid mixtures. Furthermore, it considers nonconstant fluid properties as well as longitudinal heat conduction and parasitic heat loads, which is particularly relevant in mixed refrigerant cycles for cooling of low-temperature applications. The governing equations are derived and the solution strategy is presented, followed by the model validation against analytical solutions in the corresponding limits. Finally, an exemplary heat exchanger is analyzed using both homogeneous and separated flow models, and the results are compared with experimental data from literature.


Author(s):  
C. H. Carter ◽  
J. E. Lane ◽  
J. Bentley ◽  
R. F. Davis

Silicon carbide (SiC) is the generic name for a material which is produced and fabricated by a number of processing routes. One of the three SiC materials investigated at NCSU is Norton Company's NC-430, which is produced by reaction-bonding of Si vapor with a porous SiC host which also contains free C. The Si combines with the free C to form additional SiC and a second phase of free Si. Chemical vapor deposition (CVD) of CH3SiCI3 onto a graphite substrate was employed to produce the second SiC investigated. This process yielded a theoretically dense polycrystalline material with highly oriented grains. The third SiC was a pressureless sintered material (SOHIO Hexoloy) which contains B and excess C as sintering additives. These materials are candidates for applications such as components for gas turbine, adiabatic diesel and sterling engines, recouperators and heat exchangers.


2016 ◽  
Vol 41 ◽  
pp. 268-271
Author(s):  
Luca Alberti ◽  
Adriana Angelotti ◽  
Matteo Antelmi ◽  
Ivana La Licata

Food Chain ◽  
2015 ◽  
Vol 5 (1-2) ◽  
pp. 91-104 ◽  
Author(s):  
Andrew Marchant ◽  
Andrew Graffham ◽  
Lateef Sanni ◽  
Idowu Adeoya

2000 ◽  
Vol 627 ◽  
Author(s):  
M. E. Swanson ◽  
M. Landreman ◽  
J. Michel ◽  
J. Kakalios

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.


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