Analysis of forced convective nanofluid flow through a wavy channel with linearly varying amplitude at the entrance

Abstract

Purpose The purpose of this paper is to analyze the heat and momentum transfer for steady two-dimensional incompressible nanofluid flow through a wavy channel with linearly varying amplitude in the entrance region. Design/methodology/approach The mass, momentum and energy conservation equations for laminar flow of Cu-water nanofluids are computationally solved using the finite element method. A parametric study is carried out by varying the dimensionless length of the channel section with varying amplitude (EL), Reynolds number (Re) and nanoparticle volume fraction (Φ) in the ranges 0 ≤ EL ≤ 25.5, 105 ≤ Re ≤ 900 and 0 ≤ Φ ≤ 0.04. Findings A higher heat transfer rate is seen in the wavy channel compared to a plane channel beyond a critical value of Re (Recrit) whose value varies with EL; moreover, the overall heat transfer decreases with EL. The heat transfer rate increases with phi for all EL values investigated. The combined effects of the increase in the overall heat transfer and the associated pressure drop in the wavy channel compared to the parallel plate channel are presented as performance factor (PF) against EL. For the highest value of EL (= 25.5), PF monotonically decreases with Re. For smaller values of EL (= 5.5 and 11.5) and also for EL = 0, PF decreases with Re in the lower and the higher Re regimes, while it increases in the intermediate Re regime. In all cases, PF is higher for φ = 0.04 than for the base fluid. The sensitivity of the average Nusselt number to nanoparticle volume fraction follows a non-monotonic trend with the change in Re, φ and EL. Practical implications This study finds relevance in several applications such as solar collectors, heat exchangers and heat sinks. Originality/value To the best of the authors’ knowledge, the analysis of forced convection flow of nanofluid through a wavy channel with linearly varying amplitude is reported for the first time in the literature.

Analysis of hydrothermal performance for laminar forced convective flow through a wavy channel with porous blocks

“…In addition, the performance factor for the present WCPB design is higher than that of the recent wavy channel with partially field porous media design (Kumar et al, 2022a(Kumar et al, , 2022bKumar and Pandey, 2022). As a result, the findings of the current work are recommended over the available design of wavy channel with partially filled porous media for suiatle HFF 33,6 design of effcient heat exchanging devices used for process plants, solar collectors and aerospace applications.…”

“…Now, an effort has been made to compare the performance factor of WCPB with the existing recent designs of wavy channels with partially filled porous media. The comparison of performance factor of presented WCPB with the works of Kumar et al (2022aKumar et al ( , 2022b and Kumar and Pandey (2022) at different Darcy number is depicted in Figure 12. Kumar et al (2022aKumar et al ( , 2022b It is found that the performance factor of presented WCPB is higher by 24.44%, 12.02% and 40.83% for Da = 10 À4 , 10 À3 and 10 À2 , respectively, compared to results of Kumar et al (2022aKumar et al ( , 2022b.…”

“…The comparison of performance factor of presented WCPB with the works of Kumar et al (2022aKumar et al ( , 2022b and Kumar and Pandey (2022) at different Darcy number is depicted in Figure 12. Kumar et al (2022aKumar et al ( , 2022b It is found that the performance factor of presented WCPB is higher by 24.44%, 12.02% and 40.83% for Da = 10 À4 , 10 À3 and 10 À2 , respectively, compared to results of Kumar et al (2022aKumar et al ( , 2022b. Further, Kumar and Pandey (2022) studied the performance factor for flow through a porous-corrugated channel considering triangular, sinusoidal and trapezoidal shapes when Re = 400.…”

“…Mehta et al (2022b) computationally analyzed the hydrothermal performance for flow through a ribbed wavy channel by varying the number of ribbed and their shape: rectangular, semi-circular and triangular and observed that the rectangular ribbed-wavy channel has a higher performance factor among all the configurations in the regime: 50 # Re # 125. Additionally, numerous recent research investigations relating to heat transfer enhancement have been conducted using the irregular geometries, such as the 60°C hevron plate heat exchanger (Singh and Ghosh, 2022), wavy porous layer (Ouni et al, 2022), wavy surface with finite wall thickness (Borah et al, 2022), wavy channel with linearly varying amplitude (Kumar et al, 2022a(Kumar et al, , 2022b and novel wavy fin-and-circle tube heat exchanger having concave curved vortex generators (Song et al, 2022).…”

“…However, the flow resistance by the pore decreases the mass flow rate resulting in poor thermal performance. Hence, instead of using the porous slabs (Kumar and Pandey, 2022;Kumar et al, 2022aKumar et al, , 2022bAkbarzadeh et al, 2019), installing the metallic porous blocks with higher effective thermal conductivity in the channel may effectively enhance the heat transfer rate without much decrease in the mass flow rate. To date, no work has been reported analyzing the combined effect of metallic porous block and wavy wall on the thermo-hydraulic characteristics of water flow in wavy channel.…”