In actual cooling construction of turbine blade the relative distance between circular jets c n/d n is less then 3 and the relative distance of nozzle exit to target surface is also less than 3.But the available empirical formulas were achieved on the basis of very large range of these geometric parameters.Obviously

these formulas may be inaccurate in the practical narrow range of th ese paremeters

in particular when the temperature of the turbine is very high

and on the surface of the blade exist many rows of film co oling holes.So an experimental research on the heat transfer of impingement jets has been carried out in the actual range of the geometric parameters and new empirical formulas have been established

which can be applied to the turbine blade o f the advanced aeroengine.