Numerical simulations about the discharge coefficient Cd of film cooling at narrow space were carried out in this paper

and the characteristics of the flow around film hole in small cooling channel were also investigated.Blowing rate M(0.5～2.0)

film cooling hole Reynolds number Re(5000～10000) and the ration of film cooling height to the film cooling diameter H/D(0.33～1.0) were changed to study the average discharge coefficient of a row of film holes.A finite volume method together with SIMPLE algorithm

second order upwind discrete format

was used to solve the three dimensional incompressible Navier-Stokes equations.The Realizable k-ε turbulence model was applied and non-equilibrium wall function was used for near wall treatment.The results show that the discharge coefficient Cd increases with the blowing rate M

especially when the M＜1;under the same blowing rate conditions

the discharge coefficient decreases with the Re rising faintly.In the same Re cases

the Cd becomes smaller when the H/D decreases.And the numerical results indicate that the decrease of Cd is very notable especially when H/D＜0.75.