Study On The Effect Of Particle Deposition On Film Cooling Characteristics

With the continuous development of the modern aviation industry,gas turbines are used as the main power equipment to improve the performance from generation to generation.In order to further improvement of the gas turbine performance,such as the thrust-weight ratio and efficiency,the temperature emitted from the combustion chamber to the first turbine stage will increase at all time.Due to the limitation of material properties,the blade surface is difficult to stand such high gas temperature for a long time.Therefore,the cooling technology of the blade surface is widely applied to the manufacture and design of the blade to maintain high operating stability and service life.After several decades of development,the surface cooling technology of blade has become more and more mature.As an important component,film cooling has been widely studied and applied.However,where the gas turbine is polluted or contains dust,the particulates will be exposed to high temperature and high pressure when they flow out of the combustion chamber.When they encounter cold air jets from the film cooling structure,they deposit around or inside the film holes.Phenomenon will cause the surface morphology around the hole change or produce partial blockage of the cooling hole,which will seriously affect the service life of the gas turbine.Therefore,the specific influence of particle deposition on the blade surface on the film cooling characteristics will be studied.The design of membrane hole arrangement and molding method provides a new reference index and is of great significance.Under the conditions of low or medium blow ratio,the position of the ridges has a significant effect on the cooling efficiency.The short-term loss cooling efficiency is more obvious in the position closer to the hole.The image is more obvious with shorter distance.The shape factor has a weaker effect on the cooling efficiency of the area near the film hole,and the concrete manifestation is that the adiabatic cooling efficiency slightly increases with the increasing ridge geometry;and the downstream flow along with the ridge junction size become the slightly lower with greater cooling efficiency.Under the condition of high blow ratio,the common problem of each structure is that the location factor of the ridge is not the main influencing factor of cooling efficiency and downstream flow characteristics at this time,but it can slightly influence the cooling efficiency by affecting the range and strength of kidney-shaped vortex.