Computational Fluid Dynamics Analysis of Aerodynamics and Impingement Heat Transfer From Hexagonal Arrays of Multiple Dual-Swirling Impinging Flame Jets

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Parampreet Singh ◽  
Ratna Kishore Velamati ◽  
Subhash Chander
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Target Surface ◽  
Separation Distance ◽  
Release Mechanism ◽  
Hexagonal Array ◽  
Array Configuration ◽  
Computational Fluid Dynamics Analysis ◽  
Impinging Flames

Abstract Radiative furnaces pose significant thermal inertia and single impinging flames have been observed to cause occurrence of hotspots on the target surface. Multiple burners arranged in suitable array configuration represent one of the plausible solutions for more uniform heat transfer. In this study, computational fluid dynamics (CFD) simulations have been carried out for multiple swirling impinging flames arranged in a hexagonal array configuration. The turbulence chemistry interactions in the flame field are solved numerically using renormalization group (RNG) based k–ε/eddy dissipation model (EDM) framework. Comparison of co-and-counter-swirling configurations has been studied for interactions and spent gas release mechanism. Multiple swirling impinging flames undergo strong interactions resulting in distortions of recirculation zones (RCZ) for all the surrounding except central flame. Co-swirling flames result in development of higher turbulence in the interaction regions as compared to counter-swirl case. Results indicate that some flames in counter-swirl case are underutilized due to the fluid dynamics developed in the system and co-swirling hexagonal array configuration is a better arrangement for effective heating of target surface. Effect of interjet spacing (S/Dh = 5, 7, and 9) and separation distance (H/Dh = 3, 5, 7, and 9) studied for co-swirl case revealed that peak heat fluxes decreased with increasing interjet spacing and separation distance. Central flame represented a region of low heat flux and this region has been noticed to expand in size for increasing interjet spacings. Suppression of central flame has been observed to be maximum for minimum separation distance.

scholarly journals Enhancement of Film Boiling Characteristics Using Computational Fluid Dynamics Analysis for Moving Steel Plate

2020 ◽  
Vol 6 (2) ◽  
pp. 33-42
Author(s):  
Ritu Raj ◽  
Vardan Singh Nayak
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steel Plate ◽  
Saturation Temperature ◽  
Film Boiling ◽  
Dynamics Analysis ◽  
Fluid Temperature ◽  
Plate Surface ◽  
Computational Fluid Dynamics Analysis

Present study provides guidelines and recommendations for solving film boiling problems in steel plate production, where the surface temperature of steel plate is much higher than the saturation temperature of the liquid in contact with the plate surface and the entire steel plate surface is immersed in water. Due to the boiling mass exchange occurring at the vapor liquid interface bubbles of steam are periodically produced and emitted upward such a regime is known as film boiling. A computational fluid dynamics analysis of steel plate using VOF multiphase model moving at different velocity i.e. 0.1 to 0.5 m/sec. the volume of fraction for vapor phase have been obtained for different time interval, the generation of bubbles starts moving upwards after 0.05 sec, as time goes the formation of vapor bubbles generate and collapse more rapidly because the thermal boundary is very thin and the fluid temperature around the bubbles almost equal to the saturation temperature. The thermal properties of the steel plate are implicit to be constant with temperature for convenience because the present study is focused on the boiling heat transfer on the steel plate. The size of element is set as 0.1 mm to generate mesh and quad-4 rectangular elements used are which is a rectangular in shape with four nodes on each element are applied for the analysis. Results show that that the 37.98% of Convective heat transfer coefficient of mixture is increased and 13.1% of temperature drop has been observed with 40.67% of heat flux increased for the steel plate moving at 0.1 m/sec.

Computational Fluid Dynamics Analysis for Process Impact Assessment during Thermal Pasteurization of Intact Eggs

2005 ◽  
Vol 68 (2) ◽  
pp. 366-374 ◽  
Author(s):  
SIEGFRIED DENYS ◽  
JAN G. PIETERS ◽  
KOEN DEWETTINCK
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Inactivation Kinetics ◽  
Transient Temperature ◽  
Process Conditions ◽  
Conductive Heat ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Analysis ◽  
Thermal Pasteurization

Transient temperature and albumen velocity profiles during thermal pasteurization of intact eggs were studied using a commercial computational fluid dynamics (CFD) package. Simulated temperature profiles were in close agreement with experimental data for eggs of different sizes. Convective heat transfer only occurred in the egg white fraction, and conductive heat transfer only occurred in the yolk. For process assessment, a generally accepted kinetic inactivation model for Salmonella Enteritidis was incorporated into the CFD analysis. Minimum process times and temperatures needed to provide equivalent pasteurization at 5-log reductions of the target microorganism were obtained on a theoretical basis. The combination of CFD analysis and inactivation kinetics can be very useful for assessing pasteurization of intact eggs and can enable processors to gain a better understanding of these processes and to establish process conditions for consumer-safe eggs.

scholarly journals Computational fluid dynamics analysis on heat transfer and friction factor characteristics of a turbulent flow for internally grooved tubes

2013 ◽  
Vol 17 (4) ◽  
pp. 1125-1137 ◽  
Author(s):  
P. Selvaraj ◽  
J. Sarangan ◽  
S. Suresh
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Friction Factor ◽  
Dynamics Analysis ◽  
Computational Fluid Dynamics Analysis ◽  
Plain Tube ◽  
Grooved Tube

The article presents computational fluid dynamics studies on heat transfer, pressure drop, friction factor, Nusselt number and thermal hydraulic performance of a plain tube and tube equipped with the three types of internal grooves (circular, square and trapezoidal).Water was used as the working fluid. Tests were performed for Reynolds number ranges from 5000 to 13500 for plain tube and different geometry inside grooved tubes. The maximum increase of pressure drop was obtained from numerical modeling 74% for circular, 38% for square and 78% for trapezoidal grooved tubes were compared with plain tube. Based on computational fluid dynamics analysis the average Nusselt number was increased up to 37%, 26% and 42% for circular, square and trapezoidal grooved tubes respectively while compared with the plain tube. The thermal hydraulic performance was obtained from computational fluid dynamics analysis up to 38% for circular grooved tube, 27% for square grooved tube and 40% for trapezoidal grooved tube while compared with the plain tube.

Sign in / Sign up

Export Citation Format

Share Document