Review on cooling characteristic of turbine blades in a sand and dust environment

The sand and dust particles are widely present in the atmospheric environment， and during the operation of aero-engines， a large amount of these particles are inevitably inhaled. After being heated by high-temperature combustion gases， the sand and dust particles melt and easily deposit on the turbine surface. This causes damage to the cooling structures and leads to cooling degradation， which has attracted increasing attention from researchers in recent years. This paper first decouples deposition damage and classifies it into three forms： increased surface roughness， blockage of film cooling holes， and the presence of obvious obstacles on the surface. It also summarizes the structural parameters and research scope of these three damage forms. Focusing on two critical external cooling parameters： film cooling effectiveness and external convective heat transfer， the paper provides an overview of the research methods for convective heat transfer on turbine blades under the influence of deposition damage， and reviews the effects of the three damage forms on film cooling performance and the mechanisms of cooling degradation. Overall， there are still several issues in both domestic and international research， such as the lack of correlation between deposition damage and service duration， insufficient in-depth studies of the three damage forms， and the lack of modeling and research methods for turbine blades. In the conclusion， this paper summarizes the shortcomings of current research and outlines future development directions.