Experimental investigation of fluid flow and heat transfer characteristics of a longitudinal corrugated liner for a combustion chamber

Abstract

An experimental investigation has been designed and performed to determine the fluid flow and heat transfer characteristics of a longitudinal corrugated liner for a combustion chamber. In this investigation, the detailed temperature distributions on the hot side of the liner are documented using the infrared imaging technique. Local film cooling effects are calculated from these temperature distributions. In addition, measurements of the friction factors in cooling air passages are also presented and the results are compared with previously reported studies. A range of parameter combinations of interest in cooled liner practice is covered, including combinations of variations in inlet Reynolds number of cooling air passages, the amplitude, and hole fraction of the liner. The results indicate that the film cooling effect can be improved by increasing the amplitude of the liner. However, the friction factors for the larger amplitude of the liner significantly increase and the increase trends to speed up as the Reynolds number (denoted as Rec) increases. Compared with previous works, the friction factors in the present conditions are much higher (at least by 133%) than that for parallel plate passage and circular pipes with rough walls. The larger hole fraction of the liner is more beneficial for obtaining a higher film cooling effect and has a more uniform distributions of film cooling effect in the streamwise direction. The increase of hole fraction on the windward side of the crest has little impact on the enhancement of film cooling effect. It can be expected that a nonuniform hole fraction could be utilized in the process of designing a liner for decreasing the number of film cooling holes and obtaining the same film cooling effect, instead of the uniform hole fraction presented in this study. The effect of hole fraction on the friction factor is slight.