Abstract: The cover-plate cavity is the main heat exchange component in the pre-swirl system and has a significant impact on its performance. This study first studies the heat transfer mechanism inside the cover plate cavity through numerical calculations, and then conducts heat transfer experiments on the pre-swirl system using a new measurement method based on the Newton’s law of cooling formula, to verify the rationality of the numerical results. The study mainly analyzes the radial distribution characteristics of the heat transfer coefficient and Nusselt number on the turbine disk wall surface in the cover plate cavity. The results show that the heat transfer on the turbine disk wall surface is mainly affected by the mainstream impact, and the effect of swirling flow is relatively small. The pressure ratio is strongly correlated with the mainstream impact, while the rotational Mach number is strongly correlated with the swirling flow. Changing the operating conditions essentially changes the weight of the influence of the mainstream and swirling flow on heat transfer parameters. The numerical results and experimental results have deviations of less than 10%. From the experimental results, when the pressure ratio is constant, increasing the rotational Mach number from 0.27 to 0.64 increases the average heat transfer coefficient by 11.1% to 23.2%; when the rotational Mach number is constant, increasing the pressure ratio from 1.05 to 1.15 increases the average heat transfer coefficient by 44.7%～60.5%. The research results of this study can provide a design basis for the structural design of pre-swirl systems.

Key words: pre-swirl system, disk cavity heat transfer, convective heat transfer coefficient, rotating mach number, nusselt number