Constant Temperature Boundary Research Articles

Numerical analysis of heat transfer in annulus composite material at different operation conditions

In this article natural air convection in an inclined annular cage in three dimensions is investigated numerically. This study will examine the impact of the radius ratio of an annulus on heat transfer employing two distinct methods to optimizing effective thermal conductivity: minimizing and maximizing. The annulus is built of graphite/epoxy laminated composite material. There are 12 fins attached to the inner cylinder of the two concentric cylinders that make up the annulus enclosure, which is filled with porous medium. Regarding the annulus's inclination angle “δ”, two scenarios—a horizontal annulus and a vertical annulus—are considered. Constant walls temperature boundary condition and steady state conditions apply to the system with 0.2, 0.3, 0.4 and 0.5 different radius ratio, inclination angle (0o and 90o), and modified Rayleigh number “Ra*” ranged from 10 to 500, The Nusselt number decreased for all parameters as the radius ratio Rr decreased, indicating a wider cold outer cylinder gap. For large values of modified Rayleigh number, the average Nu number ”Nuavg.” decreases with an increase in δ, and increases with a rise in the modified Rayleigh number; for low values of Ra*, δ has no effect. For horizontal, and vertical states “δ=0 o, and 90o respectively, at higher and lower thermal conductivity, the divergence of the average Nusselt is 5.1% and 10%, respectively. In horizontal cylinder adding fins on the inner cylinder is more substantial for due to its impeding effect, and NuL increases with cylinder length. For the outer cold cylinder, a link between Ra* and δ and the average Nusselt number has been established.

A three-dimensional analytical model for performance evaluation of thermoelectric generators

A three-dimensional (3D) theoretical model for thermoelectric generators (TEGs) has been developed in this paper, yielding analytical solutions for power output and energy conversion efficiency. The model comprehensively considers convective heat transfer between the thermoelectric legs and their ambient environment, as well as 3D heat conduction within the ceramic substrates. Numerical results reveal the significant influence of convective heat loss from the legs' surfaces on efficiency, especially for taller legs or higher heat convection coefficient, while having a minimal impact on power output for the constant temperature boundaries. It is shown that neglecting 3D heat conduction within the ceramic substrates leads to a substantial overestimation of TEG performance. Additionally, the complex 3D heat conduction problem for TEGs can be simplified into a more manageable 1D model with only minor adjustments to classical TEG theory. This is achieved by introducing analytical expressions for a dimensionless impact factor to quantify convective heat loss from the legs’ surfaces and the effective thermal conductance of the ceramic substrates. The proposed model serves as a valuable tool for simplifying the modeling process and optimizing the design of actual TEGs.

Numerical Investigation of Flow Inside a Channel with Elastic Vortex Generator and Elastic Wall for Heat Transfer Enhancement

In the present investigation, a detailed numerical investigation of the flow and heat transfer characteristics of a channel with an elastic fin (vortex generator) and an elastic wall has been carried out using finite element method. The Fluid-Structure Interaction (FSI) model is used to capture the interaction between the fluid and the solid structure. A sinusoidal time dependent velocity profile has been imposed at the inlet of the channel and the right half of the upper wall of the channel is heated and exposed to constant temperature boundary condition. Due to the sinusoidal velocity profile at the inlet, the elastic fin oscillates periodically and act as a vortex generator, which causes more turbulence in the flow. The obtained results showed that the Nusselt number over the heated wall is affected by the position of the flexible fin, height of flexible fin and elasticity modulus of elastic fin. Moreover, due to the elasticity of the elastic wall and sinusoidal behavior of the inlet velocity, the elastic wall oscillates periodically upward and downward. The Nusselt number values over the heated wall are increased with decrease of the elastic modulus value of the elastic wall. However, the decrease in elastic modulus value of the elastic wall contributes to an increase in the pressure drop inside the channel. It should be added that the interplay between the fluid motion and the deformable structures leads to enhanced turbulence, as the flexible fin and elastic wall introduce additional disturbances and fluctuations into the flow regime. Consequently, this heightened turbulence level has profound implications for heat transfer processes within the system.

Thermal and hydrodynamic analysis inside a channel partially filled with porous material

AbstractIn this work, the transfer of heat and changes in fluid pressure within a rectangular channel fairly packed with porous material have been studied numerically for various Darcy numbers and dimensionless porous layers. The model was run with the following assumptions: laminar flow, forced convection, isotropic porous material, local thermodynamic equilibrium, constant wall temperature boundary condition, and no thermal dissipation. The study covers a broad range for the dimensionless porous layer, 0 ≤ hr < 1, and the Darcy number, 10−4 < Da < 10−2. The fully developed and developing flow over the channel is investigated in numerical study. It was observed that the inertia effect may be disregarded when Da < 10−4. The local dimensionless bulk temperature distribution, pressure drop, and velocity profiles were all shown to be impacted by the Darcy number and dimensionless porous layers, according to the numerical analysis results. The maximum heat transfer rate was attained when the ratio of the porous layer inside the channel was 0.8, and the pressure gradient was the highest. Partial packing of the channel with a porous material has two advantages: it increases the rate heat transmission rate and results in a much smaller pressure drop than a filled porous medium.

Two-phase active immersion cooling for vertically mounted electronics with interchip component-assisted bubble departure

To address growing heat dissipation demands in high-performance computing chips, there is a transition from conventional cooling methods to advanced two-phase immersion cooling techniques for electronics thermal management. Here, we present a numerical investigation into the fluid dynamics and heat transfer in two-phase immersion cooling systems with vertically mounted chips on a printed circuit board (PCB) with interchip components such as capacitors, switches, and inductors. Leveraging a combined phase tracking and volume of fluid model, we study how the physical layout and geometries of interchip components affect the flow paths of bubbles, bubble coalescence phenomena, vapor coverage on chip surfaces, and cooling rates of heated chips. In an optimal PCB topology, a maximum heat flux of 18 W/cm2 and a heat transfer coefficient of 9650 W/m2K are observed for dielectric hydrofluoroether (HFE) - 7100 at an excessive wall temperature of 20 K under a constant wall temperature boundary condition. The research offers insights into the electronic system design to achieve efficient cooling for high-performance computing applications, demonstrating the critical role of interchip components in heat transfer.

Numerical study of uranium hexafluoride desublimation process based on Eulerian two-phase model

This paper presents a numerical study on the condensation process of uranium hexafluoride (UF6) in the supply and extraction system of a uranium enrichment plant. The numerical study was conducted using a standard UF6 receiving container with a nominal diameter of 127 mm and a volume of 8L under constant temperature boundary conditions. A phase change heat and mass transfer model for the desublimation process of uranium hexafluoride gas was established, and this model was combined with the Euler two fluid model to predict the distribution of key parameters such as temperature, pressure, and volume fraction of each phase during the UF6 cooling process, as well as the gas flow characteristics inside the container. In addition, this study also investigated the influence of various factors on the cooling rate. The research results indicated that UF6 gas initially condensed on the container wall and gradually diffused inward, with the highest solid density observed on the wall. Furthermore, increasing the inlet gas temperature, inlet mass flow rate, and reducing the cooling temperature, initial pressure inside the container could all enhance the desublimation rate to various degrees. The optimization plan proposed based on the above influencing factors could increase the yield of UF6 solid by 64.20% in 2 h, compared to the basic operating conditions.

Numerical analysis of magnetohydrodynamic free stream and radiative heat transfer flow of nanofluid in a permeable medium over a linearly stretched cylinder with Arrhenius activation energy

This research article explores the transport characteristics of magnetohydrodynamic Newtonian nanofluid flowing past a stretching cylinder in a permeable medium, considering the activation energy effects using Buongiornos mathematical model. Unlike conventional studies employing constant temperature, concentration and density boundary conditions, convective boundary conditions are utilized in this investigation. The analysis incorporates various significant parameters such as magnetic field, joule heating, viscous dissipation, thermophoresis, Brownian motion, Arrhenius activation energy, and chemical reaction. The governing equations in the form of ODEs are obtained by employing similarity variables.The MATLAB built-in solver bvp4c is employed for obtaining the solutions. The impacts of these parameters on the velocity profile, temperature profile, concentration profile, density profile, skin friction coefficient, Sherwood number, and Nusselt number are elucidated through graphical and tabular representations. The results indicate that an increase in the chemical reaction parameter leads to higher nanoparticle concentration distributions, while the activation energy parameter exhibits the opposite trend. This study holds relevance for various practical applications in applied sciences, including nuclear reactor cooling, geothermal reservoirs, chemical engineering, and thermal oil recovery.

Flow and Heat Transfer Characteristics in the Entry and Stabilized Flow Regions of a Circular Channel Rotating About a Parallel Axis

Abstract Cooling of heavy-duty electrical machines such as generators and motors is crucial for the smooth operations without thermal runaway. A commonly employed technique for the cooling of rotors in these machines is to place channels at different radial locations for the continuous passage of coolant. These channels are therefore rotating about a parallel axis, and the rotation-induced forces alter the flow and thermal behavior of the coolant compared to stationary channels. The present study reports a detailed numerical investigation on a long circular channel rotating about a parallel axis. The objective is to analyze the flow, heat transfer, and rotation-induced forces (Coriolis and centrifugal forces) in the entry region as well as in the region where flow is stable (the term ‘stable’ is used rather than ‘developed’ due to the presence of secondary flows in this region). The rotating channel was subjected to constant wall heat flux and constant wall temperature conditions at different Rotation numbers of 0, 0.15, 0.4, and 0.6. The Coriolis force is observed to be strong enough in the entry region to influence the flow. In the “stable flow” region, the centrifugal force becomes more dominant and forms counter-rotating secondary vortex pair, which causes circumferential variation in the Nusselt number. The flow and heat transfer characteristics for constant wall heat flux and wall temperature boundaries are the same for rotation conditions with similar values of rotational Grashof number. A correlation is presented for the circumferential variation of the Nusselt number in the stable flow region.

Heat transfer inside a horizontal circular enclosure with a heated semi-circular cylinder at different orientations

Natural convection inside a cylindrical enclosure is important in many industrial applications. Laminar natural convective heat transfer in the annular space between heated semi-circular cylinder in a horizontal concentric cylindrical enclosure, which has relevance to cooling of electronic components, is studied in this work. Constant wall temperature (CWT) and constant wall heat flux (CWHF) boundary conditions are considered on the inner cylinder, whereas the outer cylindrical enclosure is maintained at a fixed lower temperature. The Finite Volume Method (FVM) is used for the computations. The effect of the Rayleigh number ( Ra = 10 2 to 10 5 ) and the angular orientation of the semi-circular cylinder on the convective heat transfer is investigated. The fluid flow, temperature profile, and heat flow are visualized via streamlines, isotherms, and heatlines. Further, the overall heat transfer is explained based on the local and average Nusselt number on the inner cylinder wall. The effect of the angular orientation of the inner cylinder is noticeable for Ra ≥ 10 3 . The angular orientation ϕ = 90 ° greatly enhances the heat transfer as compared to all other orientations for all Ra ≥ 10 3 for both CWT and CWHF boundary conditions. The correlation between the average Nusselt and Rayleigh numbers for a particular orientation is proposed.

Numerical Study of Convection Heat Transfer with Confinement Around a Square Cylinder Submerged in a Water-Based Nanofluid

The novelty of this work lies in the comprehensive investigation of Forced convection heat transfer a square cylinder inclined at 45° using CuO nanofluid employing a single phase approach. A heated square cylinder with constant wall temperature boundary condition, subjected to a flowing nanofluid between two parallel walls, undergoes a laminar, steady and two-dimensional flow within a Reynolds number range of 1 < Re > 40. To obtain solutions for the flow and energy transfer, a Finite Element Method (FEM) is employed to numerically solve the governing differential equations and boundary conditions. The objective of this work is to highlight the effects of Reynolds number (Re), confinement ratio (λ), volume concentration (Φ) and diameter of nanoparticles (dnp) on fluid flow and heat transfer characteristics of nanofluid. To capture the effect of Φ and dnp in nanofluid, the thermo-physical-properties of CuO nanofluid are determined experimentally. In the results, at Re = 40, a secondary separation zone (recirculation zone) is observed near the surface of the channel wall. The drag coefficient value rises as the Φ increases and the vdnp decreases, regardless of other factors such as Re and λ. Conversely, as the confinement ratio and volume fraction of nanoparticles increase, the average Nusselt number also rises, while maintaining a constant value of Re and dnp. In contrast, the size of the nanoparticles exhibits an inverse relationship with the average Nusselt number. The study contributes to the understanding of nanofluid behavior and provides practical insights for applications, supported by correlations and Artificial Neural Network predictions (Parrales et al.).

Investigation of the Effect of Duct Geometry on Drying Air Flow in Conventional Grain Dryers by Porous Media Approach

It is a traditional practice to store many agricultural products after drying, ensuring that they are used all year round. Mixed counter flow air drying is one of the most common and traditional methods in the bulk drying process. In this application, the air flow produced by the air channels placed in the dryer bed is forced to flow through the grains in the opposite direction to the grain flow. The moisture contained in the grains is thrown out of the dryer through forced convection. However, it is expected that the air ducts installed in the dryers should not obstruct the flow of grain and provide the best possible drying performance. In this study, computational fluid dynamics (CFD) modeling for a counter-flow grain dryer was performed and the effect of the geometry of the drying channels on the process was investigated. Fluent 2020 R2 commercial software was used for 2-D flow modeling through the dryer. The airflow in the grain zone, modeled as porous media, was included in the calculation for three different geometries of the dryer air ducts (circular, angular, and straight). A constant temperature boundary condition (37°C) was applied for the air ducts in which the drying air circulated without mixing with the grain. As an output of the analysis, the dryer outlet temperature and differential pressure variation along the flow were calculated for 5 different inlet velocities (between 0.005-0.25) to determine the behavior of different air flow rates in the drying process. The increase in the inlet velocity increased the pressure difference and consequently the stability of the flow for all models. The outlet temperature decreased by about 2.5 °C with a 5-fold increase in velocity. The results showed that the sufficient outlet air for moisture removal depends on the structure of the porous medium and the flow geometry. For this analysis, the best flow was found to be for the circular cross-section model and the outlet temperature could be at acceptable levels.

Temporal numerical analysis of beeswax PCM melting in a cube geometry subjected to a constant wall temperature condition

The ability of phase change materials (PCM) to store thermal energy has gained wide application area, like battery thermal management, solar water desalination and many other. The melting process of beeswax phase change material within the cube geometry with constant wall temperature (65 °C) boundary condition has been investigated using solidification and melting model. The fluid flow and heat transfer governing equations are solved using second order finite volume scheme. A PRESTO algorithm is applied for pressure-velocity coupling. The convergence criteria of 10−10 have been selected for energy equation, while 10−8 is selected for both momentum and continuity equations. The results like percentage variation along length-height and height-width plane for transient liquid fraction and temperature has been plotted, along with velocity streamlines within the cube geometry. From the obtained results it is concluded that the melting fraction and temperature of beeswax PCM is different in different planes and the major factors which affect the complete melting process is wall temperature, and the geometry. A difference of more than 0.1 °C in temperature has been recorded between mid-length-height and height-width plane while a difference of more than 2% in liquid fraction of PCM is observed. Even the uniformity of temperature and liquid fraction is notably influenced and vary along length, height, and width of cube geometry. Thus, it is concluded that melting process of PCM may affect the ability to store and release the heat energy which further affect the performance parameters of applied physical system.

Investigation of the role of charge injection and Coulomb force during the melting of phase-change materials under constant temperature boundary conditions

This paper presents an investigation of the melting of dielectric material in a rectangular cavity under the effect of electrohydrodynamics (EHD). First, phase-change modeling is implemented to simulate the melting performance of paraffin wax without EHD under constant temperature boundary conditions until a steady-state condition is achieved. Next, the whole set of coupled EHD equations is introduced to the model, with the Coulomb force using a Heaviside function for charge injection being the only electrical body force considered. Finally, the numerical model is implemented using the finite element method to solve for the electric field, flow field, temperature field, and charge transport. The numerical results show that, under the effect of EHD, melting continues due to the generation of electroconvection cells in the liquid phase-change material and the flow field manifests as two symmetric rotational cells generated between every two successive electrodes. The flow field causes the redistribution of the temperature field in the liquid bulk, which enhances the heat transfer. Melting continues until a steady-state condition is almost reestablished after about one hour. The enhancement factor, defined as the ratio of the EHD melt thickness to the steady-state melt thickness without EHD, is 2.33 at 6 kV applied voltage.

Numerical thermal performance assessment of phase change process in a PCM/foam-fins enclosure under various thermal conditions

ABSTRACT The low ability of phase change material (PCM) to transfer thermal energy has created a serious challenge for the development of latent heat storage (LHTES) units. Embedding foam with high thermal conductivity material like copper has attracted significant attention. Besides, high porosity, lightweight, and easy usage are other important benefits of copper. However, its higher cost and decreasing effective volume of PCM led to the creation of amendments in the foam design. Employment of the foam in the form of fin or foam fin has emerged as an alternative method to benefit from the advantages of porous material and overcome its defects. In this study, various LHTES units with different numbers of foam fins have been simulated numerically and compared with pure PCM and fully foam PCM enclosures. Two practical boundary conditions including constant temperature and constant heat flux were examined for the designed systems. The obtained results demonstrated that foam fins have a remarkable effect on the thermal performance enhancement of LHTES under constant temperature boundary condition. For LHTES with six foam fins, 42% and 30% reductions in melting time were achieved for both types of boundary conditions including constant temperature and heat flux, respectively. At the beginning of charging process, a significant enhancement of input heat rate was proved for LHTES with 6 foam fins and fully foam up to 112% and 155%, respectively. In addition, the foam fins method provided some free volume of PCM to permit the falling out of natural convection of molten PCM.

Experimental Analysis of Additively Manufactured Latticework Coupons

Abstract The capabilities and the precision of additive manufacturing processes have been tremendously increased in the last years, and this trend is not expected to be close to an end. Researchers, in the gas turbine industry, are focusing on the technology implementation on cooling systems. The aim of the present work is to investigate the performances of eight different geometries in order to exploit the cooling potential of some challenging latticework schemes with respect to traditional ones such as smooth channel, dimples, and pin fins. Test coupons consisting of those cooling structures embedded inside a rectangular cooling channel with dimensions of 56 mm width, 5 mm height, and 68 mm length were fabricated by means of direct metal laser melting technique. Since an aim of the present work is to evaluate the shape deformation associated with this additive process, the results of the CT scan imaging technique are presented. The performances are characterized both in terms of averaged heat transfer and friction factor values inside the test coupons by means of steady-state technique with a constant wall temperature boundary condition. The investigated flow Reynolds numbers range from 18, 000 to 40, 000. These values allow the authors to provide a deeper understanding of the latticework structures performances at Reynolds numbers beyond the range typically investigated in the literature. An efficiency index is employed to compare the performances of each geometry. Although the obtained results reveal that none of the tested geometries outperforms the other ones, the latticework arrangements show a heat transfer enhancement with respect to a porosity decrease. In addition, the good capability in terms of heat transfer of the lattice structures measured in the present work suggests the use of such technologies for twofold optimization process based on mechanical resistance and heat transfer characteristics.

Investigating heat transmission in a wellbore for Low-Temperature, Open-Loop geothermal systems

Heat transfer processes in geothermal wellbores are an essential component to overall system performance, but can be overlooked in subsurface modelling studies that tend to focus on reservoir response. This study addresses heat transfer in the wellbore through a comprehensive modelling study of 10 different parameters on OpenGeoSys software designed to evaluate heat losses during open-loop production conditions for typical low-temperature (<100 °C) single phase geothermal systems. Models were set-up to focus on wellbore effects only, using a single production well with constant fluid inlet temperature boundary condition. Results indicate that under base case conditions for a 2-km deep well surrounded by rock formations with a thermal conductivity of 2.5 W/(m.K) and bottom-hole temperature of 60 °C, the difference in inlet (reservoir) and production (wellhead) temperature at the end of a 40-year production period is 2.06 °C. This corresponds to minimum heat losses into the surrounding formations of −63.3 W/m, which is ∼ 7 % of the thermal power recorded at the wellhead (assuming a rejection temperature of 30 °C) and a 3.4 % difference to bottom-hole temperature. These losses in heat can be significant, particularly when in combination with surface losses through the heat exchanger or in the reservoir through thermal breakthrough. Wellbore insulation can reduce losses, but it would appear this only impacts the short-term. Wellbore performance can also be improved, with heat losses minimized, when developing wells above the reservoir interval in low thermal conductivity rock with high geothermal gradients.

Numerical simulation of fluid flow and heat transfer in steady state laminar natural convection in horizontal circular cylindrical enclosures

Heat transfer by natural convection often occurs in a closed enclosure in various applications. Different geometries of the cross section of a two-dimensional enclosure, such as triangle, rectangle, and trapezoid have already been investigated. In this research, a regular polygon with twelve sides is considered. The study focuses on the rate of heat transfer through the enclosure, using one side of the polygon as the hot surface and another side as the cold surface. The dodecagon can serve as a model for circular cylindrical enclosures under constant temperature boundary conditions over a specified length. The Nusselt number of the enclosure is obtained for each side as the hot surface. Both the lowest and highest Nusselt numbers are evaluated based on the position of the cold side. The findings reveal that the highest Nusselt number does not necessarily correspond to configurations where the hot and cold sides are directly opposite each other. In situations where convection heat transfer through the enclosure is the predominant mode of heat transfer, the Nusselt number is a power function of the Rayleigh number. Conversely, a logarithmic relationship is observed in cases of conduction heat transfer within the enclosure.

Effects of buoyancy in a laminar flow of supercritical carbon dioxide in a horizontal microchannel at different gravities

The effects of buoyancy were generally neglected in convective heat transfer inside horizontal microchannels because gravitational effects diminish compared to inertial and viscous forces with diminishing length scale. However, buoyancy effects can be significant for supercritical carbon dioxide (sCO2) slightly above the critical condition in microchannels, and the heat transfer coefficient can peak because of abrupt changes in the fluid's thermophysical properties. Previous studies considered buoyancy in channels with hydraulic diameter above 500 μm at a constant surface heat flux boundary condition. These effects were not well understood for microchannels with a hydraulic diameter as small as 100 μm, particularly with constant wall temperature boundary condition, but they hold great potential in the design of micro heat exchangers.This study numerically investigated the effects of buoyancy inside a 100-μm hydraulic diameter square microchannel with a total length of 27 mm and a heated length of 25 mm for laminar flow of sCO2. A total of 180 cases were analyzed to predict the effects of surface temperature ranging from 310 to 350 K, pressure ranging from 8 to 10 MPa, Reynolds numbers from 100 to 500, and gravitational acceleration from 0 g to 3 g, on the heat transfer. It was revealed that gravity has a significant effect on the heat transfer coefficient and on the thermal entrance length. The average heat transfer coefficient was increased by up to 138% on the bottom surface of the channel for 3 g compared to 0 g. The thermal entrance length showed a mixed behavior, such as it was increased for certain conditions while decreased for other conditions. For some cases, it was also observed that the pressure drop increased slightly with increasing gravity, and it was directly proportional to the wall shear stress. Finally, it was concluded that the gravity had a significant effect on the flow and heat transfer characteristics but was negligible for Richardson number below 10−4.

Thermal-hydraulic and load following performance analysis of a heat pipe cooled reactor

Heat pipe cooled reactors have gained attention as a potential solution for nuclear power generation in space and deep sea applications because of their simple design, scalability, safety and reliability. However, under complex operating conditions, a control strategy for variable load operation is necessary. This paper presents a two-dimensional transient characteristics analysis program for a heat pipe cooled reactor and proposes a variable load control strategy using the recuperator bypass (CSURB). The program was verified against previous studies, and steady-state and step-load operating conditions were calculated. For normal operating condition, the predicted temperature distribution with constant heat pipe temperature boundary conditions agrees well with the literature, with a maximum temperature difference of 0.4 K. With the implementation of the control strategy using the recuperator bypass (CSURB) proposed in this paper, it becomes feasible to achieve variable load operation and return the system to a steady state solely through the self-regulation of the reactor, without the need to operate the control drum. The average temperature difference of the fuel does not exceed 1 % at the four power levels of 70 %,80 %, 90 % and 100 % Full power. The output power of the turbine can match the load change process, and the temperature difference between the inlet and outlet of the turbine increases as the power decreases.

Cyclic Heat Transfer Solver for OpenFOAM

Channels with periodically repeating geometries are often simulated using periodic or cyclic boundary conditions. By calculating the temperature and flow field in one periodic module, the resulting distributions can be generalized to multiple modules. This reduces the computational load by simulating a single module versus the whole structure. This is a particularly useful approach when performing large optimisation studies of periodic geometries, such as compact heat exchangers. Currently, OpenFOAM only supports cyclic boundary conditions for pressure and momentum, but not heat transfer. The present work introduces a steady and an unsteady solver for cyclic heat transfer with constant wall temperature boundary conditions. The solver is validated against analytical Hagen-Poiseuille flow and two configurations of periodic wavy channels. In the latter case, the results are compared to existing literature.