Entropy analysis in a mixed convective Carreau nanofluid flow around a wedge: impact of activation energy and sinusoidal magnetic field

Abstract

A wide range of real-world applications have proven the importance of non-Newtonian fluids near a wedge, including the oil and gas industry, the aerospace sector. This study elucidates the dynamics of a Carreau nanofluid around a wedge by combining entropy analysis with periodic magnetohydrodynamics (MHD) and activation energy. The dimensional partial differential equations (PDEs) that describe the fluid flow system undergo non-similar transformations, forming nondimensional PDEs. The numerical solution to these PDEs is obtained by applying quasilinearization followed by the implicit finite difference approach. In the case of n = 0.5 (power-law index), when We (Weissenberg number) improves from 0 to 4, surface friction $\left(R{e}^{1/2}{C}_f\right)$ upsurges by approximately 23% and declines by around 41% in the case of n = 1.5. The mass transport intensity of liquid oxygen is about 18% higher than liquid nitrogen’s. Increasing the wedge angle results in a significant increase in fluid velocity.

KEYWORDS:

• Periodic MHD
• Carreau nanofluid
• activation energy
• mixed convection
• entropy analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

H	=	nondimensional concentration (liquid nitrogen)
We	=	Weissenberg number
G	=	nondimensional temperature
Re	=	Reynolds number
T	=	dimensional temperature (K)
Pr	=	Prandtl number
S	=	nondimensional nanoparticles’ concentration
Nb	=	Brownian diffusion characteristic
Ri	=	Richardson number
Nt	=	thermophoresis attribute
G	=	gravitational acceleration (ms−2)
$C$	=	liquid nitrogen concentration (mol/L)
Kc	=	chemical reaction attribute
f	=	nondimensional stream function
Le	=	Lewis number
Sc	=	Schmidt number
u, v	=	velocity components (ms−1)
M	=	magnetic parameter
E	=	dimensionless activation energy
$u_{\mathrm{\infty }}$	=	mainstream velocity constant (ms−1)
$T_{\mathrm{\infty }}$	=	mainstream temperature (K)
$T_w$	=	wall temperature (K)
F	=	nondimensional velocity
$R^{\ast }$	=	gas constant (Jmol−1K−1)
Ec	=	Eckert number

Greek signs

${\text{β}}_1,{\text{β}}_2$	=	thermal concentration expansion coefficient
${\text{β}}_3,{\text{β}}_4$	=	concentration expansion coefficient
${\text{β}}_t,{\text{β}}_c$	=	quadratic convection parameter for temperature and concentration
$\sigma$	=	electrical conductivity (Sm−1)
${\mathrm{\Omega }}_{\theta }$	=	nanoparticle density difference ratio
$\psi$	=	stream function (m2s−1)
${\mathrm{\Omega }}_T$	=	temperature difference ratio
$\phi$	=	half angle of the wedge (rd)
$\theta$	=	nanoparticles concentration (mol/L)
$\nu$	=	kinematic viscosity (m2s−1)
$\xi ,\eta$	=	transformed variables

Abbreviations

AE	=	Activation Energy
EG	=	Entropy Generation

Additional information

Funding

This work was supported by the DST/INSPIRE Fellowship/2019/IF190225, awarded to the second author by the Department of Science and Technology, Ministry of Science and Technology, India, Innovation in Science Pursuit for Inspired Research (INSPIRE), New Delhi.