Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Theoretical Justification of Thermoresistive-Anemometric Method for Verification of the Average Molecular Weight of Hydrocarbons in Non-Isothermal Conditions E.A. BITIUKOVA, A.A. KHVOSTOV, V.I. RYAZHSKIKH, A.V. IVANOV Using the structure of the rheological law for a stepped fluid in which the regularization principle and Carrot’s relation are applied, the conjugate mathematical model for identification of hydrodynamic and thermal nonstationary fields in the internal problem of free thermoconvection of hydrocarbons with a locally distributed heat source functioning due to heating according to the Joule-Lenz effect, has been synthesized. Computational experiments confirmed the linkage between the average molecular weight of the polymer in solution, and the geometric characteristics of the computational domain, as well as hydrodynamic and thermal fields. Keywords: hydrocarbons, polymer molecular weight, non-Newtonian fluid, natural convection, mathematical modelling. DOI: 10.25791/pribor.9.2023.1441 Pp. 38-46.