Double-jet film-cooling geometries on a flat plate were investigated using pressure sensitive paint (PSP) measurement technique. The spanwise distance between the double-jet film-cooling holes varied as 0

0.5 and 1.0

while the streamwise distance was kept as 3.0. The density ratio was 1.0

1.5 and 2.5

while the blowing ratio was 0.5

1.0

1.5 and 2.0. The effects of spanwise distance and density ratio on the effectiveness of double-jet film-cooling holes were studied. The results showed

at spanwise distance of 0

the lateral coverage of the film was suppressed. As the spanwise distance increased

the film covered more areas. However

while the spanwise distance was too large

the film coverage degraded. With the increase of density ratio

the lifting-off of the jets weakened

and the film-cooling effectiveness improved. At high density ratios

higher film-cooling effectiveness was achieved by the double-jet film-cooling holes with larger spanwise distance.