Adiabatic wall temperature and heat transfer downstream of injection through two rows of holes

Results of an experimental investigation of film cooling and heat transfer following injection through two staggered rows of holes are reported. The two staggered rows are considerably more effective in protecting the wall than a single row. The film cooling effectiveness at locations beyond about 30-hole dia downstream of injection is laterally uniform. The heat transfer coefficient is within a few percent of that without injection at low blowing rates, but it increases rapidly as the blowing rate increases above unity.