Effect of area ratio of impingement hole to effusion hole on heat transfer characteristics of impingement-effusion composite cooling

The influence of area ratio to heat transfer characteristics of impingement-effusion double wall was investigated numerically,under the precondition of the same equivalent hole area.Results show that,with the decrease of area ratio of impinging hole to effusion hole,film flow velocity decreases,impinge cooling heat flux increases,and the cooling effectiveness enhances.The heat fluxes of hot side wall,cold side wall and effusion hole wall decrease with the area ratio,but the last one decreases least,and its quotient among the total heat flux increases.