For heat transfer enhancement in heat exchangers, different types of channels are often tested. The performance of heat exchangers can be made better by considering geometry composed of sinusoidally curved walls. This research studies the modeling and simulation of airflow through a

The wavy channels in which the contraction and expansion regions are created periodically is very essential in most of the devices for enhancing the heat distribution, pressure reduction, and maximizing the flow rate. Because of having the expansion and the contraction regions, the fluid passage through these channels attains an automatically created periodicity. Having the periodic variation in the cross-sectional area, the fluid gains a regime of fully developed that is quite different from those channels having the constant cross-sectional area. Fluid flow problems in the wavy channels are often studied to examine the separated flows in which separated vortices are formed in the expansion regions, patterns of the flow velocity, pressure patterns, and the temperature distribution due to the periodic variation. Due to the periodic variation in the parameters of the geometry, the pattern of the fluid movement is largely affected by the flow velocities, loss in pressure, and heat enhancements [

In [

Besides all these works there is much effort devoted by researchers in last few years in modeling nanofluids flows through different curvy geometries with application in energy storage, drug delivery, cancer treatment, tissue generation, readers are referred to the works [

The current problem of the fluid flow and heat transfer is tested by making the open channel who's upper and lower boundaries are shaped up by using the cosine function see

The modeling and simulation for the present fluid flow and heat transfer problem are examined by considering the steady-state, two-dimensional, and incompressible Newtonian fluid. We use COMSOL Multiphysics 5.4 for the simulation which implements streamline-upwind Petrov-Galerkin's finite element method [

The heat transfer for the fluids in the vector form and in component form can be written as by

Following boundary conditions are set:

Slip boundary condition at upper and lower walls

Fully developed flow conditions at inlet and outlet of the channel are respectively

and

It is the describable quality of the finite element procedures to get the results up to the benchmark by performing a mesh independent study for the fluid flow problem and heat transfer. To approve the current fluid flow problem for a sinusoidally curved wavy channel a mesh independent study is performed along the channel. For this reason, five different types of meshes are practiced to estimate the ratio of the centerline horizontal component of velocity

Statistics for extremely fine mesh as well different other meshes are given by the following

Data | Extremely fine mesh | Extra fine | Finer | Fine | Normal |
---|---|---|---|---|---|

Mesh vertices | 21347 | 5014 | 3313 | 2347 | 1272 |

Triangular elements | 41674 | 9532 | 6224 | 4350 | 2298 |

After doing the mesh independent study, we are adjusting our intention to approve the results for the local Nusselt number downstream of the channel by exploring the correlation available through different pieces of literature. According to the literature, the local Nusselt number for a flat plate in the state of forced convection is provided by the equation correlating the local Reynolds number and Prandtl number [

The laminar and Newtonian fluid flow onward with heat transfer was tested with the use of the Reynolds number

The streamlines pattern with the surface plots is dispatched in

In

Applying a linear Regression procedure, we would make the correlation that will connect the maximum velocity at the outlet of the channel in terms of Reynolds number. Following equation is valid for the period of vibration

Pressure contours are obtained in

In

Pressure drop at the outlet of the channel is the function of Reynolds number as well as that of the period of vibration. By increasing the values of

Mostly in the industrial area, the wavy/curvy channels are constructed due to the need of optimum pressure in the region of interest. When the elements of any fluid passing through the contracted region the volumes are reduced which results a significant increase in the pressure. In

Also, with the increase in Reynolds number the range of periodicity increases for example

In the field of fluid dynamics, the wall shear stress can be regarded as the rate at which the velocity inclines while the fluid is moving along the wall. In common, shear stresses are occurring when the elements of fluid acquiring the motion relative to one another. For a simple pipe, zero velocity is assumed at the pipe wall whereas it is increasing while the fluid element is moving towards the center of the pipe. For a non-smooth pipe, the determination of the wall shear stress is essential. Here, we are going to present the graphs for wall shear stress against the length of the pipe see

It is often can be seen in the fluid flow problems which are observed under the presence of the bluff bodies, cavities and might be they can be observed due to the periodic motion of the boundaries of the channel, the fluid often rotates along its axis. The rotational regions becomes clearer when the fluid is observed under the presence of bluff bodies or obstacles rather than without of them. When fluid with any material slides down upstream of the channel, the rotating regions can be observed along the sides of the downstream. The length and intensity of these rotating regions depend upon the velocity of the fluids. The fluid needs some velocity magnitude to form the vortex along with the downstream of the region. While observing the wavy channel in the current problem the rotating regions were observed in

Although, there was no rotational region found for the period

The heat distribution in the channel is investigated by imposing a temperature at the outlet of the channel and the air is allowed to enter the domain with an initial temperature. Our concern is to lessen the temperature near to the outlet of the channel by searching such a Reynolds number and the period of the vibration of the boundaries. The temperature distributions with the surface plots in the channel are presented in

Therefore, the graphical presentation (see

The present work encountered airflow and temperature distribution through a sinusoidally curved wavy channel of length

Velocity field of the fluid in two dimensions

Outlet temperature

Reynolds number

Dynamic pressure

Length of the channel

Specific heat of air at constant pressure

Period of vibration of boundaries

Standard thermal conductivity of the air

Amplitude of vibration boundaries

Temperature in the domain

Height of the contracted region

Nusselt number

Inlet velocity

Average Nusselt number

Inlet Temperature

Prandtl Number

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