Investigation of Non-Isothermal Flow in a U-Shaped Tube in the Presence of Natural Convection

Abstract

The article examines the effect of the presence of natural convection on the formation of the thermoelectrokinetic effect in aqueous solutions of ionic compounds. The fields of temperatures and velocities of a liquid located in a U-shaped tube, which is heated from below in the presence of natural and forced convection, are calculated. The model is based on the unsteady Navier --- Stokes equations in the Boussinesq approximation, the thermal conductivity equation, and the continuity condition, supplemented by boundary conditions for forced and natural convection. The solution is obtained using a finite element method with a quadratic approximation of velocity and a linear approximation of pressure and temperature. A numerical analysis of the distribution of temperature and velocity fields at a fixed flow velocity is carried out. The structure of flows in the coils of a U-shaped tube, their spatial localization and quantitative characteristics are determined. The results demonstrate an asymmetric temperature distribution in the tube knees and localization of a sharp temperature gradient in the inlet knee due to the interaction of free and forced convection. The averaged and integral characteristics of the temperature field obtained by numerical calculation are consistent with the experimental results, which indicates the adequacy of the model used. The resulting model will be refined and generalized to simulate thermoelectromagnetic phenomena resulting from self-organization processes caused by natural convection in viscous electrically conductive media

Please cite this article in English as:

Sidorov A.V., Grabov V.M., Zaitsev A.A., et al. Investigation of non-isothermal flow in a U-shaped tube in the presence of natural convection. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2026, no. 3 (126), pp. 53--72 (in Russ.). EDN: LDXYRF

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