A Numerical Investigation of the Effects of Steam Ingestion on Compression System Performance

Abstract

Steam ingestion into a gas turbine engine compression system can have effects on performance and operability. It is important to be able to quantify these effects. This paper describes a preliminary technique developed to model steam ingestion in a gas turbine engine compression system using a loosely coupled technique of a one-dimensional (1-D) vaporization code and a 1-D meanline compressor performance code. The results are presented for two separate parametric studies: first, the effects of the quantity of steam; and second, the effects of the quality of steam. The analytical results are evaluated against the observed industry standards. These results show that steam ingestion does have an effect on compression system performance and, potentially, operability. The effects can be seen in an increase in incidence from the front to the back blades of the machine, which results in stage rematching. These effects are caused mainly as a result of heat transfer during vaporization of the liquid water present in steam with quality less than 100 percent. The effects of fluid property changes (gas constant and specific heat ratio), caused by the addition of the vaporized water, are secondary.