Thermal and friction characteristics of a circular tube fitted with perforated hollow circular cylinder inserts

Singh, Sumit Kumar; Kumar, Manoj; Kumar, Alok; Gautam, Abhishek; Chamoli, Sunil

doi:10.1016/j.applthermaleng.2017.10.090

Cited by 71 publications

(17 citation statements)

References 33 publications

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“…In addition, using a numerical approach, it is possible to obtain the different component of the permeability tensor [25]. From a more general perspective, this kind of numerical approach is spreading fast to different fields of science, such the design of heat exchanger [26,27,28] or static mixer [29,30].…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamics of a packed bed of non-spherical polydisperse particles: A fully virtual approach validated by experiments

Pozzobon

Colin

Perré

2018

Chemical Engineering Journal

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This work presents a numerical workflow to generate a virtual packed bed made of non-spherical polydisperse particles, and subsequently predict its permeability. Wood chips were taken as an illustration. First, chips are sized before being recreated numerically. Then, using LMGC90, a DEM code, a packed bed made of those chips was generated. Once bed internal had been sampled, CFD tools belonging to the OpenFOAM library were used to mesh the geometry (snappyHexMesh) and compute fluid motion (simpleFoam). Finally, using numerical results, the bed permeability was computed in both Stokes and inertial regimes-turbulence being described by Launder-Reece-Rodi model. In parallel, experimental measurements of the permeability of a packed bed, made of the exact same wood chips, was carried out. These experiments were used as a reference to challenge numerical results. The permeability value delivered by the workflow is 16.0 % higher than the experimental value. This value has to be compared with Kozeny-Carman equation estimation which overestimates bed permeability by 115 %. Going one step further, this framework was successfully used to compute inertial effects constant of the Forshheimer equation for our packed bed. Throughout this article, a special care has been taken in explaining and evaluating the impact of all the key parameters, namely, number of particles that have to be sized, mesh refinement level, numerical domain dimensions. This workflow opens the door to numerical estimation of bed tortuosity, dispersion coefficients, volumetric heat exchange coefficients, and much more, using the particle size distribution as unique input data.

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Section: Introductionmentioning

confidence: 99%

Hydrodynamics of a packed bed of non-spherical polydisperse particles: A fully virtual approach validated by experiments

Pozzobon

Colin

Perré

2018

Chemical Engineering Journal

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“…Throughout the experiments, temperatures, air volumetric flow rate and pressure drop were measured with various equipment's, the uncertainties [7] of Nu, Re and f were calculated. The maximum uncertainties were ±2.42% for Nu, ±3.08% for f, and ±1.48 % for Re in this work.…”

Section: Data Reductionmentioning

confidence: 99%

Numerical and Experimental Investigations on Performance Evaluation of a Conical Offset Vortex Generator Inserts to Improve Convective Heat Transfer Coefficient

Mundhe

Bindu

2020

Journal of Thermal Engineering

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The passive augmentation technique is widely used by researchers from thermal engineering field and it has shown excellent results for convective heat transfer rate. This paper shows the numerical and experimental findings for convective heat transfer characteristics and friction coefficient. Tests were conducted for turbulent flow, using air as medium through a uniformly heated steel pipe containing a novel kind of insert named as Conical offset Vortex Generator (COVG). The simulation tests were performed for turbulent flow with varying Reynolds number in the range 4000 to 50000. The parameters were analyzed during tests are pitch to smooth tube diameter ratio (p/d) and angle of attack (α). Various simulation tests were carried out with the help of ANSYS Fluent software to optimize the geometry. The simulation tests were carried out for different angle of attack (α = 15°, 30°, 60°). COVG with angle of attack (α = 60°) shows more enhancement in heat transfer rate, hence it was used for the experimentation purpose. The experimentation is conducted for various pitch to diameter (p/d = 1.18, 1.97, 3.94). The numerical and experimental results show improvement in heat transfer rate as there is decrease in pitch to smooth tube diameter ratio (p/d) and it also increases the value of friction factor. The reason behind the improvement in heat transfer rate is that, the braking of thermal boundary layer near the wall surface. Experimental results show the enhancement of Nusselt number from 3.46-6.7.

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“…e effects of tip edge ratio and flow attack angle for the winglet on heat transfer, pressure loss, and performance were studied for Re � 3500-16,000. ey claimed the winglet vortex generator in the heat exchanger gives the best thermal performance in the range 1.72-2.20. Singh et al [23] studied the influences of the perforated hollow circular cylinder in a circular tube for Re � 6000-27,000. ey found that the perforated hollow circular cylinder in the circular tube provides the heat transfer rate around 150-230% when compared with the smooth tube. Chamoli et al [24] illustrated the convective heat transfer in a circular tube fitted with perforated vortex generators.…”

Section: Introductionmentioning

confidence: 99%

Thermohydraulic Performance Improvement in Heat Exchanger Square Duct Inserted with 45° Inclined Square Ring

Boonloi

Jedsadaratanachai

2020

Modelling and Simulation in Engineering

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Thermal performance development, heat transfer structure, and flow behavior in the heat exchanger square duct equipped with a 45° inclined square ring are investigated numerically. The effects of flow blockage ratios and spacing ratios for the inclined square ring on fluid flow and heat transfer are considered. The Reynolds number (Re = 100–2000, laminar regime) based on the hydraulic diameter of the square duct is selected for the present work. The numerical domain of the square duct inserted with the 45° inclined square ring is solved with the finite volume method. The SIMPLE algorithm is picked for the numerical investigation. The heat transfer characteristics and flow topologies in the square duct inserted with the inclined square ring are plotted in the numerical report. The heat transfer rate, pressure loss, and efficiency for the square duct placed with the inclined square ring are presented in forms of Nusselt number, friction factor, and thermal enhancement factor, respectively. As the numerical results, it is detected that the heat transfer rate of the heat exchanger square duct inserted with the inclined square ring is around 1.00–10.05 times over the smooth duct with no inclined square ring. Additionally, the maximum thermal enhancement factor for the heat exchanger square duct inserted with the inclined square ring is around 2.84.

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Thermal and friction characteristics of a circular tube fitted with perforated hollow circular cylinder inserts

Cited by 71 publications

References 33 publications

Hydrodynamics of a packed bed of non-spherical polydisperse particles: A fully virtual approach validated by experiments

Hydrodynamics of a packed bed of non-spherical polydisperse particles: A fully virtual approach validated by experiments

Numerical and Experimental Investigations on Performance Evaluation of a Conical Offset Vortex Generator Inserts to Improve Convective Heat Transfer Coefficient

Thermohydraulic Performance Improvement in Heat Exchanger Square Duct Inserted with 45° Inclined Square Ring

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