Pulsating flow effects on convection heat transfer in a corrugated channel: A LBM approach

Jafari, Mohammad; Farhadi, Mousa; Sedighi, Kurosh

doi:10.1016/j.icheatmasstransfer.2013.04.006

Cited by 73 publications

(14 citation statements)

References 25 publications

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“…For heat transfer enhancement applications, Strouhal number values between 0 and 1 are recommended to achieve significant heat transfer enhancement due to flow pulsation [26]. For each radiator, Fig.…”

Section: Cfd Simulation Of Pulsed Flow Radiatormentioning

confidence: 99%

Thermal performance of hydronic radiator with flow pulsation – Numerical investigation

Embaye

Al-Dadah

Mahmoud

2015

Applied Thermal Engineering

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h i g h l i g h t s CFD simulation of type 10 and type 11 panel radiators with constant and pulsed flow conditions. Pulsating the flow enhances the heat transfer performance of panel radiators. As flow pulsating frequency increases, the specific heat output of panel radiators increases. Pulsating the flow resulted in energy saving of up to 17% for type 10 and 20% for type 11 radiators. a b s t r a c t Improving the heat output of hydronic central heating system in buildings can play a major role in energy saving. Current panel radiators of central heating systems are operating at constant flow strategy with thermostat control device. Such operating mode is not efficient in terms of energy consumption; therefore an alternative operating scenario is required to enhance the heat output of the panel radiator. The main aim of this research is to investigate the effect of pulsed flow input on the energy consumption of panel radiators while maintaining the target panel surface temperature. CFD modelling of two hydronic panel radiators with constant and pulsating flows were developed using the conjugate heat transfer module in COMSOL Multiphysics software. The radiators used were one with single finned surface (type11) and the second is without fins (type10), both with the dimensions of 500 mm long and 300 mm high. The CFD results of the constant flow conditions were compared to published experimental work showing good agreement with maximum deviation of 2.4% in the heat output. To investigate the effects of pulsating flow on the performance of the two panel radiators, a wide range of input pulsating flows with amplitude ranging from 0.027 m/s to 0.051 m/s and frequency ranging from 0.0523 rad/s to 0.209 rad/s while the flow supply temperature remained constant at 75 were simulated. The simulation results showed that using pulsed flow can reduce the energy consumption of panel radiators by up to 20% compared to constant flow operating condition while maintaining the same radiator surface temperature of 50 C. Such results highlight the potential of using pulsed flow to reduce the energy consumption of central heating systems in buildings without compromising the user comfort.

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Section: Cfd Simulation Of Pulsed Flow Radiatormentioning

confidence: 99%

Thermal performance of hydronic radiator with flow pulsation – Numerical investigation

Embaye

Al-Dadah

Mahmoud

2015

Applied Thermal Engineering

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“…Pulsed flows are widely used in various industrial applications, such as the cooling system of gas turbine engines and the heat exchangers in milli-scale or micro-scale electronics devices where the Reynolds number (R e ) is usually low and the flow is laminar [34]. Shahin [35] performed experimental and theoretical studies on the pulsed flow of a nanofluid in a pipe and in a concentric annulus, and found that the application of pulsed flow enhances and improves the heat transfer by 25% for certain flow conditions.…”

Section: Introductionmentioning

confidence: 99%

“…Shahin [35] performed experimental and theoretical studies on the pulsed flow of a nanofluid in a pipe and in a concentric annulus, and found that the application of pulsed flow enhances and improves the heat transfer by 25% for certain flow conditions. Using the Lattice Boltzmann Method (LBM), Jafari et al [34] performed a computational study on the effect of pulsed flow on heat transfer in a corrugated channel. They also found that the pulsed flow affects the velocity and the temperature fields leading to an enhancement of the heat transfer.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Flow of Nanofluids in a Y-Type Intersection Channel with Multiple Pulsations: A Numerical Study

Massoudi

Yan

2017

Energies

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Abstract:In this paper, we study pulsed flow and heat transfer in water-Al 2 O 3 nanofluids in a Y-type intersection channel with two inlets and one outlet. At the two inlets, two sinusoidal velocities with a phase difference of π are applied. We assume that the shear viscosity and the thermal conductivity of the nanofluids depend on the nanoparticles concentration. The motion of the nanoparticles is modeled by a convention-diffusion equation, where the effects of the Brownian motion, thermophoretic diffusion, etc., are included. The effects of pulse frequency, pulse amplitude and nanoparticles concentration on the heat transfer are explored numerically at various Reynolds numbers. The results show that the application of the pulsed flow improves the heat transfer efficiency (Nusselt number) for most of the cases studied. Amongst the four factors considered, the effect of the frequency seems to be the most important.

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“…On the other hand, pulsating flow has gained more attention for medical and biological applications [18,43]. Some studies have shown an improved heat transfer for pulsating flow [44][45][46]. Moreover, significantly improvement in performance of ultrafiltration has been claimed in another investigation [20].…”

Section: Introductionmentioning

confidence: 99%

Effect of module design and flow patterns on performance of membrane distillation process

Ali

Aimar

Drioli

2015

Chemical Engineering Journal

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h i g h l i g h t sEffect of fiber configurations and flow patterns on MD performance has been studied. Undulating fibers show best performance in terms of flux at low feed flow rates. Helical modules and intermittent flows exhibit better energy efficiency. Intermittent and pulsatile flows are the best optimum. a b s t r a c tThe present study highlights the effect of different hollow fiber membrane configurations and flow patterns on performance of membrane distillation (MD) process. The modules with helical and wavy conformations have been tested under various hydrodynamic conditions and their performance has been compared with conventional straight fiber modules. The effect of flow patterns has been studied by applying the intermittent and pulsating flows to straight hollow fiber membranes. A flux enhancement of 47% and 52% with respect to the straight fibers has been observed for helical and wavy configurations, respectively, though packing density of such modules is significantly less than their straight counterparts. For intermittent flow, an improvement of $30% has been recorded. The difference is more prominent at low flow rates and approaches to the straight fiber performance under steady flow at high Reynolds numbers (Re) for all hollow fiber configurations and flow patterns studied. The intermittent flow and wavy fibers exhibit an energy efficiency enhancement of $180% and $90% over their conventional counter parts, respectively. In terms of surface and volume based enhancement factor and packing density, intermittent and pulsating flow exhibited the most optimal performance.

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Pulsating flow effects on convection heat transfer in a corrugated channel: A LBM approach

Cited by 73 publications

References 25 publications

Thermal performance of hydronic radiator with flow pulsation – Numerical investigation

Thermal performance of hydronic radiator with flow pulsation – Numerical investigation

Heat Transfer and Flow of Nanofluids in a Y-Type Intersection Channel with Multiple Pulsations: A Numerical Study

Effect of module design and flow patterns on performance of membrane distillation process

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