Effect of the error in determination of the heat transfer coefficient on the simulation data for heat and mass transfer

Abstract

In a rigorous way, nonstationary problems of convective heat transfer should be treated in the conjugate statement where the condition of conjugation of the heat transfer medium and the channel wall temperature fields at their interface is used [1–3]. However, the difficulties, such as lack, as a rule, of complete data on the distribution of turbulent momentum and heat transfer coefficients over the channel cross-section, inherent restrictions of the existing models of turbulence, and the geometrical complexity of the solution domain, force researchers to consider an alternative approach where the heat transfer from the moving gas medium to the channel walls is described by the Newton–Richman law [4]. In this case, the local coefficient of convective heat transfer is determined by well-known criterial experimental relations, which are valid for a steady flow of the heat carrier [4, 5]. This simplified approach cannot be rigorously substantiated by invoking the quasistationarity principle or by introducing correction factors, and comparison of numerical and experimental data for evaluating the calculation accuracy is not always possible. An attempt is made to determine the domain of applicability of the simplified approach by evaluating the effect of the error that arises in the estimation of the heat transfer coefficient on the parameters of a convective flow.