In order to study the heat transfer characteristics of impingement/cocurrent convection/film double cooling

several test pieces were designed.The experimental results show that the cooling efficiency increases with the growing blowing ratio;the distribution of cooling efficiency is wavy on the cooling wall.The cooling efficiency is higher in the areas of cooling film exit and the impingement stagnant point.The decrease of cooling efficiency is weakened behind the impingement stagnant point.Cooling efficiency increases with the decrease of impingement space.