Simulation of the Heat Transfer to a Laminar Flow in a PRIMIX Static Mixer

2004 ◽  
Author(s):  
R. F. Mudde ◽  
R. J. R. Van de Kleij ◽  
R. Beugels
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Laminar Flow ◽  
Numerical Simulations ◽  
Tube Wall ◽  
Heated Wall ◽  
Static Mixer ◽  
Laminar Regime ◽  
Static Mixers ◽  
Process Fluid

The heat transfer from the wall to the process fluid in a PRIMIX helical static mixer has been investigated using numerical simulations. The flow is in the laminar regime, Re = 7 to 18. The simulations concentrate on heat transfer from a heated wall to the process fluid. Two different mixers are examined. A conventional one in which the elements are not connected to the wall of the tube and a special one, in which the elements are soldered to the tube wall. In the latter case the heat transfer is enhanced by about 23% which is attractive when dealing with fluids with a low thermal conductivity. The results of the numerical simulations are compared to experiments, both with soldered and without soldered elements. The comparison is good, showing the capabilities of numerical simulations for studying and optimizing heat transfer in static mixers.

Simulation of the Laminar Flow in a PRIMIX Static Mixer

2002 ◽  
Author(s):  
R. F. Mudde ◽  
C. Van Pijpen ◽  
R. Beugels
Keyword(s):  
Pressure Drop ◽  
Particle Tracking ◽  
Experimental Validation ◽  
Independent Solution ◽  
High Accuracy ◽  
Static Mixer ◽  
Laminar Regime ◽  
Time Step ◽  
Static Mixers ◽  
Direct Use

The PRIMIX helical static mixer has been investigated using numerical simulations. The flow is in the laminar regime (Re = 1 to 1000). The simulations concentrate on the pressure drop and on the use of particle tracking for mixing studies. For the pressure drop, experimental validation is provided. It is found that the pressure drop can be simulated with high accuracy for Re < 350. For higher Re-values no grid independent solution could be obtained and the experimental results no longer agree with those of the simulations. The simulated pressure drop results scaled to the empty pipe pressure drop, can be well summarized as K = 4.99 + Re/31.4. Using Particle Tracking it has been possible to reproduce literature data. However, it has been shown that the obtained results are rather sensitive to the choice of the time step. This limits the direct use of particle tracking techniques for studying the mixing of static mixers in the laminar regime.

Influence of Transverse Fins Attached to the Heated Wall of a Rayleigh-Be´nard Cavity

2004 ◽  
Author(s):  
Darren L. Hitt ◽  
Antonio Campo
Keyword(s):  
Thermal Conductivity ◽  
Nusselt Number ◽  
Numerical Simulations ◽  
Heat Transport ◽  
Local Heat ◽  
Heated Wall ◽  
Lower Plate ◽  
Maximum Heat ◽  
Rayleigh Numbers ◽  
Fin Spacing

In this article we examine the augmentation of classic Rayleigh-Be´nard convection by the addition of periodically-spaced tranverse fins attached to the heated, lower plate. The respective impacts of the fin size, the fin spacing and the thermal conductivity of the fin material are examined through numerical simulations for different laminar Rayleigh numbers and reported it terms of the Nusselt number. With the exception of very closely spaced fins, the heat transport is observed to exceed that of the idealized Rayleigh-Be´nard case. It is found that local heat transport maxima and minima do exist for specific fin spacings and that the maxima become more pronounced at higher Rayleigh numbers. For ‘small fins’ the fin spacing corresponding to maximum heat transport is such that the fin spacing is approximately equal to the enclosure height.

Quantitative Mixing Analysis of Laminar Flow in Circle Grid Perforated Plate with 50% Porosity Static Mixer

2014 ◽  
Vol 541-542 ◽  
pp. 836-840 ◽  
Author(s):  
Mat Loddin Mohd Zamadi ◽  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Laminar Flow ◽  
Fluid Dynamic ◽  
Perforated Plate ◽  
Reynolds Numbers ◽  
Manufacturing Cost ◽  
Static Mixer ◽  
New Approach ◽  
Static Mixers ◽  
Ansys Cfx ◽  
Research Findings

The applications of the static mixers are widely applied in many industries to obtain the desired type of mixing. In this context, to perform the mixing process should have two different fluids that also have different properties which will combines it in a single equipment to make an another fluid. The main objective of this research study is to propose a new approach of fractal concept (circle grid perforated plate) for internal rapid mixing by determining the coefficient of variation (COV). This study was implemented by fully numerical simulations. The simulations of mixing fluid were carried out with the help of commercial computational fluid dynamic (CFD) package ANSYS CFX 14.0 software. The simulation was done primarily in cylindrical pipe with insertions of circle grid perforated plate with porosity of 50%. Three levels of laminar flow have been chosen to result in Reynolds numbers (Re) equal to 100, 200 and 400. The effectiveness of circle grid perforated plate static mixer has been evaluated by comparing the homogeneity level of mixing fluids to the Kenics static mixer that readily available in industries applications. Based on the research findings, the COV value for circle grid perforated plate with 50% porosity at Re 100 was 0.0744 which is out of the range while Reynolds number at 200 and 400 were 0.0483 and 0.0247 respectively which are in the range in term of reasonable target of mixing homogeneity. The values of COV between 0.01 and 0.05 are the reasonable target for many applications. In term of manufacturing cost and energy loss due to static mixer, definitely this new approach of 50% porosity circle grid perforated plate is better design compared to the Kenics static mixer because of lower number of inserts and simpler design of static mixer to produce.

Conjugate heat transfer analysis for laminar flow in pipes having a step change in boundary conditions and wall conductivity

2007 ◽  
Vol 221 (8) ◽  
pp. 919-925 ◽  
Author(s):  
M E Arici ◽  
M E Kaya
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Solid Wall ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Step Change ◽  
Heat Transfer Analysis ◽  
Heated Wall ◽  
Surface Boundary ◽  
Wall Conductivity

The current procedure is to examine the effects of wall axial conduction on heat transfer for laminar flow in pipes. The procedure combines the analytical solution of the problem of the fluid region with a numerical approximation of conduction of the solid wall and has the capability of handling the step change in outer surface boundary condition and wall thermal conductivity. The pipe under investigation is divided into two sections: non-heated and heated ones, and the conductivities of the sections are assumed to be different. The obtained results show that the local heat transfer parameters such as wall and fluid temperatures, and Nusselt number are greatly influenced by the step change in wall conductivity and the partially heated wall arrangement. The results of the present study may have applications in the design of heat transfer devices.

scholarly journals Heat transfer intensification of Zirconia/water nanofluid

2017 ◽  
Vol 13 ◽  
pp. 01-08
Author(s):  
Mohamed Iqbal Shajahan ◽  
Chockalingam Sundar Raj ◽  
Sambandan Arul ◽  
Palanisamy Rathnakumar
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Laminar Flow ◽  
Friction Factor ◽  
Volume Concentration ◽  
Constant Heat Flux ◽  
Particle Volume ◽  
Heat Transfer Intensification ◽  
Nusselt Numbers ◽  
Thermal Analyser

This paper investigated convective heat transfer and friction factor of ZrO2/H2O nanofluid through a circular pipe under laminar flow condition with constant heat flux. Nanofluid is prepared for 0.5, 0.75 and 1% volume concentrations with yttrium oxide surfactant. Nanofluid’s thermal conductivity and viscosity is measured by KD2 Pro thermal analyser and Brookfield viscometer respectively. Results showed that the thermal conductivity and viscosity increased with increase in particle volume concentration. These nanofluids are experimented in a forced convection system, first heat transfer characteristics of DI (Deionised) water  under laminar flow in a copper tube measured, then three nanofluids are carried out the tests, results revealed that the enhanced Nusselt numbers of 21.09,28.05 and 35.73%  at the 0.5, 0.75 and 1% volume concentrations, There is no excess penalty in pumping power  and results showed  less variations in friction factor for nanofluids comparatively with the base fluid DIWater.

scholarly journals Effect of magnetic field on the steady nanofluid flow past obstacle

2021 ◽  
Vol 22 (3) ◽  
pp. 535-542
Author(s):  
Yacine Khelili ◽  
Rafik Bouakkaz
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Laminar Flow ◽  
Hartmann Number ◽  
Volume Fraction ◽  
Transverse Magnetic ◽  
Heated Wall ◽  
Cylinder Wake ◽  
Flow And Heat Transfer ◽  
Model Transition

The fluid flow and heat transfer of a nanofluid past a circular cylinder in a rectangular duct under a strong transverse magnetic field is studied numerically using a quasitwo-dimensional model. Transition from laminar flow with separation to creeping laminar flow is determined as a function of Hartmann number and the volume fraction of nanoparticle, as are critical Hartmann number, and the heat transfer from the heated wall to the fluid. Downstream cross-stream mixing induced by the cylinder wake was found to increase heat transfer. The successive changes in the flow pattern are studied as a function of the Hartmann number. Suppression of vortex shedding occurs as the Hartmann number increases.

Numerical Study of the Heat Transfer Rate in a Helical Static Mixer

2006 ◽  
Vol 128 (8) ◽  
pp. 769-783 ◽  
Author(s):  
Ramin K. Rahmani ◽  
Theo G. Keith ◽  
Anahita Ayasoufi
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Static Mixer ◽  
Flow Conditions ◽  
Modern Approach ◽  
Static Mixers

In chemical processing industries, heating, cooling, and other thermal processing of viscous fluids are an integral part of the unit operations. Static mixers are often used in continuous mixing, heat transfer, and chemical reactions applications. In spite of widespread usage, the flow physics of static mixers is not fully understood. For a given application, besides experimentation, the modern approach to resolve this is to use powerful computational fluid dynamics tools to study static mixer performance. This paper extends a previous study by the authors on an industrial helical static mixer and investigates heat transfer and mixing mechanisms within a helical static mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer under both laminar and turbulent flow conditions. The turbulent flow cases were solved using k−ω model. The effects of different flow conditions on the performance of the mixer are studied. Also, the effects of different thermal boundary conditions on the heat transfer rate in static mixer are studied. Heat transfer rates for a flow in a pipe containing no mixer are compared to that with a helical static mixer.

Effect of Porosity on Circle Grid Perforated Plate Performance as a Static Mixer in Laminar Flow

2015 ◽  
Vol 786 ◽  
pp. 188-192
Author(s):  
Bukhari Manshoor ◽  
M.Z. Mat Loddin ◽  
Amir Khalid ◽  
Izzuddin Zaman
Keyword(s):  
Laminar Flow ◽  
Perforated Plate ◽  
Reynolds Numbers ◽  
Static Mixer ◽  
New Approach ◽  
Static Mixers ◽  
Ansys Cfx ◽  
Industry Applications ◽  
Simulation Results ◽  
The Many

Mixing is one of the important processes to the many industries. Fluid mixing process typically involves three phases of fluid in the form of liquids, gases and solids. To obtain a desired type of mixing, one of the devices that can be use is a static mixer. In this study, a perforated plate static mixer with circle grid fractal design with two grades of porosity which are 50% and 75% will introduce. The purpose of implementing the two grades porosity of perforated plate in this study is to determine a performance of the two static mixers. In order to achieve the objective, the simulations of mixing fluid were carried out by using ANSYS CFX software. The simulation was carrying out primarily in cylindrical pipe with insertions of circle grid perforated plate. Three levels of laminar flow had been used which is Reynolds numbers (Re) equal to 100, 200 and 400. The performance of circle grid perforated plate static mixer will be evaluated by determining the Coefficient of Variation (COV). The simulation results also were compared in term of homogeneity level of mixing fluids to the Kenics static mixer. Based on the simulation results, the value of COV at selected plane in pipeline simulated for Kenics static mixer and the two grades porosity of perforated plate at Re = 400 are 0.000703, 0.0247and 0.00427 respectively. Since the values of COV between 0.01 and 0.05 are a reasonable target for many industry applications, the results for new approach of static mixer represent completely homogeneous mixing fluid for this application. Definitely this new approach of circle grid perforated plate with fractal design gave better results because of lower number of inserts and simple design of static mixer.

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