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. 2022 Jan 15;12(2):276. doi: 10.3390/nano12020276
(r,θ,z) Cylindrical coordinate system (m)
w0 Constant mass flux velocity (m/s)
T Constant ambient temperature (K)
P Pressure (Kg/m. s2)
k Thermal conductivity (W/(m. K))
qr Radiative heat flux
Pr Prandtl number
T Temperature of the fluid (K)
cp Specific heat at constant pressure (J/Kg. K)
F(ξ),G(ξ) Dimensionless velocity stream function
Tw Constant surface temperature (K)
S Mass suction parameter
vw Rotating velocity of the disk (m/s)
Rd Radiation parameter
uw Surface velocity of the disk (m/s)
Nur Local Nusselt number
ue,ve,we Free-stream velocities (m/s)
Cfr Skin friction coefficient along the radial direction
a Constant parameter having units (m. s)−1
Cfθ Skin friction coefficient along the azimuthal direction
(u,v,w) Velocity components (m/s)
Rer Local Reynolds number
Greek Symbols
α Thermal diffusivity (m2/s)
υf Kinematic viscosity (m2/s)
αA Rotating disk parameter
σv Tangential momentum accommodation coefficient
λ0 Coefficient of the main free path
θ(ξ) Dimensionless temperature
σT Thermal accommodation coefficient
ω Constant angular velocity (m/s)
γ Specific heat ratio
λ Stretching/Shrinking parameter
σ* Stefan-Boltzmann constant (W/(m2. K4))
μ Absolute viscosity (N. s/m2)
ξ Pseudo-similarity variable
ρ Density (kg/m3)
k* Mean absorption constant
ψ Stream function
δ1 Velocity slip parameter
ϕ Solid volume fraction of nanoparticles
δ2 Temperature slip parameter
Acronyms
Cu Copper
PDEs Partial differential equations
H2O Water
ODEs Ordinary differential equations
bvp4c Boundary value problem of the fourth order
Al2O3 Alumina
2D, 3D Two and three-dimensional
BCs Boundary conditions
N-S Navier-Stokes equation
ICs Initial conditions
Subscripts
hnf Hybrid nanofluid
1,2 Hybrid nanoparticles (Cu and Al2O3)
f Working base fluid
w Wall boundary condition
Far-field condition
Superscript
Derivative with respect to ξ