Experimental investigations of the cooling characteristics of a vane end-wall were carried out in a hot wind tunnel using infrared thermograph technique. Two mainstream-to-coolant temperature ratios of 1.53 and 2.29

and three coolant-to-mainstream mass flow ratios of 0.50%

1.25% and 1.50% were chosen. Comparing the results obtained at high and low temperature ratio

the following three conclusions can be drawn. The experimental method of increasing the temperature ratio by increasing the mainstream temperature and keeping the coolant temperature constant led to a significant increase in the overall cooling effectiveness of the end-wall surface. The cooling characteristics of the end-wall surface changed as the temperature ratio increased. As the temperature ratio had different effect of cooling effectiveness at different positions of the end-wall

the areas with high and low cooling effectiveness changed. The scheme of hole-layout suitable for low temperature ratio may not be applicable to high temperature ratio. The effect of temperature ratio on the cooling characteristics was great at the leading edge

but not evident at the trailing edge.