Simulation of nanomaterial turbulent modeling in appearance of compound swirl device concerning exergy drop

2019 ◽  
Vol 534 ◽  
pp. 122121 ◽  
Author(s):  
Sun Wei ◽  
M. Jafaryar ◽  
M. Sheikholeslami ◽  
Ahmad Shafee ◽  
Trung Nguyen-Thoi ◽  
...  
Keyword(s):  
1980 ◽  
Author(s):  
Carmen Cerasoli ◽  
Coleman duP. Donaldson ◽  
Guido Sandri

Inventions ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 33
Author(s):  
Horng-Wen Wu ◽  
Tang-Hong Chen ◽  
Nugroho-Putra Kelana ◽  
De-An Huang

This study analyzes transient turbulent modeling of three-dimensional multiple dimpled fin array using large eddy simulation (LES). The Navier–Stokes equations as well as the energy equation were constructed by the finite volume method and then discretized to form algebraic equations, which were solved by semi-implicit method for pressure-linked equation (SIMPLE). The solutions of temperature and velocity were obtained by iterating computation until it converged within each step. This simulation places nine fins on the bottom surface of a channel and changes the height of the dimple (0.4, 0.8, and 1.2 mm) with three different levels of Reynolds number (Re) (3500, 5000, and 6500) to investigate the temperature and flow field without gravity in forced convection. The results indicate that the dimpled fin array can generate vortices between the convex/concave dimples and the fin base and increase the influences of the height of the dimple on the flow field around the fin array. The averaged time-mean of the Nusselt number (Nu) for the dimple height of 0.8 mm is higher than that of the no-dimple case up to 14.4%, while the averaged time-mean Nu for the dimple height of 1.2 mm is lower than that of the no-dimple case up to 11.6%.


2005 ◽  
Vol 33 (2) ◽  
pp. 426-427 ◽  
Author(s):  
D. Bernardi ◽  
V. Colombo ◽  
E. Ghedini ◽  
A. Mentrelli

Author(s):  
Reza Ghafouri-Azar

Turbulent flow of heavy water through the primary loop of CANDU steam generators is associated with a number of known failure mechanisms such as flow accelerated corrosion, flow induced vibration and mechanical fatigue. The primary causes of these failures, or degradations, are interactions of the turbulence effect of fluid with the surrounding structure. Using Computational Fluid Dynamics and heat transfer techniques the flow fields inside hot leg and cold side of the steam generator were analyzed to study the nature of the flow fields inside the 2 halves of the primary head. The model used to investigate the flow field was a three-dimensional k-omega turbulence flow model. The solutions of the analysis can be used to investigate the effects of flow on components close to the divider plate and tubesheet including locking tabs and skin fix inside the halves. The effect of turbulence was investigated by varying the inlet nozzle sizes and locations.


2020 ◽  
Vol 14 ◽  

In this work a comparative analysis of a turbulent jet experiment produced by the injection of dyed water into a shallow tank filled with water of the same density and the results of a numerical modelare presented. Dye was injected with the source fluid as a tracer. The concentration of the dye in the shallow turbulent flow was determined using a video imaging technique.The present laboratory experiments were conducted in a tank of small depth, and it is significantly wide to avoid the effect of the side walls. The space between the parallel walls of the tank can be varied during the experiments. The large-scale turbulent flow in the water sheet between the walls of the tank is confined to essentially two-dimensional motion. The shear on the bottom of the tank is a momentum sink to be considered.A comparison of the numerical resultswith the experimental data showed a very good agreement in terms of the position reached by the jet at different times after injection is initialized. These findings are useful for turbulent modeling of the shallow shear flow and for application to the large scale heat and mass exchange processes in lagoons, lakes, the ocean and the atmosphere


Author(s):  
Nawaf Alkhamis ◽  
Ali Anqi ◽  
Dennis E. Oztekin ◽  
Abdulmohsen Alsaiari ◽  
Alparslan Oztekin

Computational fluid dynamics simulation will be conducted for multicomponent fluid flows in a channel containing spacers. The Navier-Stokes equation and the species transport equations are solved for various values of Reynolds numbers. The membrane will be modeled as a functional surface, where the membrane fluxes of each component will be determined based on the local partial pressures of each species, the permeability and the selectivity of the membrane. Laminar flow modeling is employed for the flow inside the channel without the spacers; while k-ω turbulent modeling is used to simulate the flow inside the channel with the spacer, for Re = 100, 150 and 200. The spacers are placed in an inline arrangement. The presence of spacers in the channel improves the membrane performance at Re = 200. The effects of the spacer on the separation process at low flow speeds (Re = 100 and 150) are negligible. The performance of the system will be measured by the maximum mass separation with minimal friction losses.


2008 ◽  
Vol 42 (7) ◽  
pp. 556-565 ◽  
Author(s):  
Felipe Aristizabal ◽  
Richard J. Munz ◽  
Dimitrios Berk

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