Research on the radiation scaling criteria of film-cooled gas turbines

The escalating gas turbine (GT) inlet temperature and the amplifying radiation effect of multi-component radiation gases aggravate the thermal radiation phenomena. In addition, the omission of radiation effect in the classical film cooling scaling criteria makes the research data obtained under relative low temperature conditions invalid. This paper provided a mechanistic-level explanation of the influence of the thermal radiation term on the energy equation, and subsequently introduced two novel dimensionless parameters (radiation number and optical thickness) that can effectively reflect the radiation impact on scaling criteria. Furthermore, three parameter matching schemes were proposed to enable the data match of high and low temperature conditions for adiabatic cooling effectiveness, overall cooling effectiveness, and dimensionless radiation heat flux. Compared to the high temperature test method, the scaling criteria can provide valuable insights into the film cooling behavior under realistic GT conditions. The method proposed in this paper can not only help prevent material loss and energy waste but also align with the principles of energy conservation, emission reduction, and sustainable development.