Analysis of the methods for calculating heat transfer in regard to the MS-20 brand motor aviation oil under conditions of forced convection in the ring channel given their verification with the experiment

Abstract

Based on experimental studies of the thermal processes in an annular oil channel with the internal heated replaceable metal tube, an experimental database was created. Experimental values of the heat transfer coefficient in regard to the MS-20 aircraft engine oil under its forced convection at various heat flux densities, pressures and pumping rates were calculated based on the experiment results using the Newton — Richmann formula. The authors of the article also created an experimental formula to calculate the Nusselt number. The results obtained were verified by comparing the experimental research results with results of other authors. Theoretical values of the heat transfer coefficient were obtained from the Nusselt number formulas presented by various authors. Formulas and the Nusselt number calculation formulas were analyzed, as well as the heat transfer coefficient in regard to the liquid heat carriers exposed to their forced convection presented by various authors. Graphs and tables compare calculation results according to the theoretical formulas by various authors and calculation results according to the experimental formula of the authors of the article with results of the experimental study. It was established that the experimental formula of the authors of the article was the most accurate and workable. Recommendations are given for calculating the heat transfer coefficient in regard to the MS-20 aircraft engine oil in the annular channel under various thermodynamic conditions. It is proposed to introduce the methodology in conducting an experimental study and creating experimental formulas for calculating the Nusselt number and the heat transfer coefficient in regard to the MS-20 brand aircraft engine oil in studying the other aviation engine oils.