Investigation On Flow And Heat Transfer Characteristics In Compound Cooling Configuration Of Chamber Wall

Design of Combustor liner wall cooling structure is very important in combustor design,whether to have a successful design will have important impact on the performance and reliability of combustor.Liner wall compound cooling is a kind of novel cooling technology,which includes impingement+effusion cooling,impingement+convection+film cooling etc.In contrast with traditional film cooling,it has uniform temperature distribution and lower wall temperature with less cooling air flow rate, so it is very prospective in gas turbine combustor wall cooling configuration design.Flow field and temperature distribution in Impingement+effusion cooling structure are studied through numerical simulation and experiment method,and get the relations between cooling efficiency and aerodynamic,geometry parameters.It shows that the cold air flow coming from effusion holes will inject into mainflow and there is a pair of opposite swirling vortexes at the exit of effusion holes;The inclination angle has important effects on cooling efficiency,generally speaking, reducing the inclination angle could increase the cooling efficiency;staggered placement is better than aligned arrangement;for given streamwise space ratio,the shorter cross space ratio is ,the higher the cooling efficiency is;with respect to impingement+effusion compound cooling configuration,impingement distance has nothing to with cooling efficiency in this paper's parameter.Based on the temperature distribution in floating tile impingement+effusion cooling structure,thermal stress distribution is studied using finite software,and get some conclusions that thermal stress and deformation vary with blowing ratio.At last, A numerical study is performed to investigate the flow and temperature fields for impingement + reversed convection(with fin-pins) + film cooling configuration,and get the rules how blowing ratio,number of rows of fin-pins,pattern of placement,impingement distance impact cooling efficiency respectively. It shows that the number of rows of fin-pins has little impact on cooling efficiency,staggered placement is better than aligned arrangement,and the advantage grows bigger as blow ratio increases;impingement distance has certain impact on cooling efficiency,generally speaking,cooling efficiency grows bigger as impingement distance is reduced.,the configuration whose dimensionless impingement distance is 2.14 has the biggest cooling efficiency.When blowing ratio is bigger than 1.0,there is nearly no difference between configuration with dimensionless impingement distance 2.86 and that with3.57.