An impinging heat transfer experiment in a contraction channel,obtained by simplifying and magnifying the strut in the inlet of a gas turbine engine,was carried out by adopting narrow-band thermochromic liquid crystal(TLC) transient measurement technique.The effects of the diameter of impingement hole,impingent distance and the height of the channel on Nusselt number distribution and quantities were studied.The results show that the heat transfer in the channel was enhanced with the increasing diameter of the impingent holes and the height of the channel,or the decreasing impingent distance.Meanwhile the distribution change of Nusselt number and the increase of mean Nusselt number on the sidewall and the leading edge are different.In addition,the primary dominating factor for the heat transfer in the channel is the diameter of the impinging holes,and the slightest factor is the height of the channel.