Computational analysis of film cooling effectiveness using novel semicircular hole shapes with streamwise inclination of 30o has been carried out. Pitch to diameter ratios of 3.0 has been investigated. Reynolds Averaged Navier-Stoke equation solver FLUENT with standard k- turbulence model is used for simulations. Coolant to mainstream blowing ratios is varied from 1.33-2.0. It is observed that for the streamwise region x/D<20 the centerline and laterally averaged effectiveness values from a row of semicircular holes are higher than that from a row of circular holes due to the less jet lift-off of coolant jet. For a row of semicircular holes, mean coolant jet heights are lower than that from a row of circular holes. Simulations for two rows of inlined and staggered semicircular holes are also carried out and the results are compared with single row of full circular holes. It is found that centerline and laterally averaged effectiveness values from 2 rows of semicircular holes are much higher than a single row of full circular hole case at all streamwise regions at all blowing ratios tested. Among all the cases studied, effectiveness values from two staggered rows of semicircular holes are found to be highest. Jet lift-off is found minimum from two staggered row of semicircular holes. For all cases studied, the mean coolant jet heights from two staggered rows of semicircular holes are found minimum. Results for counter rotating vortex pairs from all cases at plane normal to mainstream