Film cooling on a convex surface with zero pressure gradient flow

The adiabatic film cooling effectiveness and heat transfer increase due to film injection was investigated on a convex surface at zero pressure gradie nt flow. Film cooling results were obtained using thermochromic liquid crys tals to measure the local wail temperature distribution. Five different inj ection configurations, three with cylindrical and two with shaped holes wer e examined. Coolant injection with cylindrical holes indicates decreased fi lm cooling effectiveness and increased heat transfer at moderate and high b lowing rates. Significant higher film cooling effectiveness values and lowe r heat transfer increase due to film injection were achieved by shaped hole injection compared to cylindrical hole injection. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.