This paper presents computational analysis of centerline film cooling effectiveness using Navier-Stokes equation solver. Film cooling effectiveness has been varied along the downstream of cooling holes. The computational model has been validated with benchmark experimental literature. Computational study compares film cooling effectiveness over various blowing ratios (M) and various hole shapes. The k-ω shear stress transport model of FLUENT software has been used for the computational analysis. The hole geometry and blowing ratios have important effects on film cooling effectiveness. Computational results reveal that film cooling effectiveness increases with increase in blowing ratio whereas effectiveness decreases due to intermixing of coolant and mainstream flow and due to coolant jet lift off. The best results were obtained for fan-shaped hole with M=1.00. While for lower blowing ratio, coolant is unable to spread over a longer distance downstream of cooling holes.