Linear Stability of a Combined Convective Flow in an Annulus
Fluids 2023
Armands Gricāns, Valentīna Koliškina, Andrejs Koliškins, Felikss Sadirbajevs

Linear stability analysis of a combined convective flow in an annulus is performed in the paper. The base flow is generated by two factors: (a) different constant wall temperatures and (b) heat release as a result of a chemical reaction that takes place in the fluid. The nonlinear boundary value problem for the distribution of the base flow temperature is analyzed using bifurcation analysis. The linear stability problem is solved numerically using a collocation method. Two separate cases are considered: Case 1 (non-zero different constant wall temperatures) and Case 2 (zero wall temperatures). Numerical calculations show that the development of instability is different for Cases 1 and 2. Multiple minima on the marginal stability curves are found for Case 1 as the Prandtl number increases. Concurrence between local minima leads to the selection of the global minimum in such a way that a finite jump in the value of the wave number is observed for some values of the Prandtl number. All marginal stability curves for Case 2 have one minimum in the range of the Prandtl numbers considered. The corresponding critical values of the Grashof number decrease monotonically as the Prandtl number grows.


Atslēgas vārdi
linear stability; convective flow; bifurcation analysis; collocation method
DOI
10.3390/fluids8040130
Hipersaite
https://www.mdpi.com/2311-5521/8/4/130

Gricāns, A., Koliškina, V., Koliškins, A., Sadirbajevs, F. Linear Stability of a Combined Convective Flow in an Annulus. Fluids, 2023, Vol. 8, No. 4, Article number 130. e-ISSN 2311-5521. Pieejams: doi:10.3390/fluids8040130

Publikācijas valoda
English (en)
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