Numerical Investigation On Film Cooling Characteristics Of Flame Tube And Irregular Disturbing Flow Lamilloy-slit

Based on the cooling requirements of the aero-engine combustor flame tube,the paper studies the problem of the wall cooling of the combustor chamber with small pressure and the cooling of the special-shaped lamilloy.Based on the real working condition of the engine combustor,taken the annular combustion chamber as the research object.Three cooling methods were designed including the traditional slot film cooling,multi-straight hole film cooling and multi-inclined film cooling for the combustion chamber wall,three-dimensional simulation of the combustion about the combustion,flow and heat transfer were carried out among each cooling structure.The result shows that among the various cooling structures,compared with the the traditional film cooling structure,the cooling gas volume of the multi-straight hole cooling structure and the multi-inclined hole cooling structure decreases up to 34%.In addition the temperature gradient of the flame tube wall with multi-straight hole and multi-straight hole cooling structure is greatly reduced compared with the traditional film cooling structure.Compared with the multi-straight hole cooling structure,the multi-inclined hole cooling method has smaller flow resistance and higher cooling efficiency.Taken a small unit body on the wall of the flame tube,which is simplified into a laminate,and the heat transfer characteristics about the shaped lamilloy cooling are studied.The special-shaped lamilloy is designed with three kinds of flow patterns,two kinds of flow arrangement,three impact hole diameters and two cold air outlet inclination angles.The orthogonal test design method is used to design 9 kinds of special-shaped lamilloy,which use numerical simulation method to understand its flow and heat transfer characteristics.The research shows that the heat transfer in the front end of the cooling structure of the layer cooling structure is stronger.With the increasing of the flow direction distance,the heat transfer in the channel of the lamilloy column is gradually weakened;from the perspective of the cooling efficiency of the insulation film of the layer cooling structure,The highest of the circular spoiler,followed by the rhombic spoiler,the lowest of the plum-shaped spoiler;and the cooling efficiency of the adiabatic film increases with the diameter of the inlet,and the 30 ? cold air outlet slopes is higher than 45 ?.