Evaporation modelling of water droplets in a transonic compressor cascade under fogging conditions

Authors

Adrian Seck - University of Stuttgart
Silvio Geist - Helmut Schmidt University, Hamburg
Janneck Harbeck - Helmut Schmidt University, Hamburg
Bernhard Weigand - University of Stuttgart
Franz Joos - Helmut Schmidt University, Hamburg

Abstract

The high-fogging technique is widely used to rapidly increase the power output of stationary gas turbines. Therefore, water droplets are injected into the inflow air and a considerable part enters the compressor. Within this paper, the primary process of droplet evaporation is closely investigated. A short discussion about the influencing parameters states a major significance of the slip velocity between ambient gas flow and droplets. Hence, experimental results from a transonic compressor cascade are shown to evaluate the conditions in real high-fogging applications. The measured parameter range is used for direct numerical simulations to extract the evaporation rate depending on inflow conditions and relative humidity. Finally, an adapted correlation in the form of Sh(Re1/2Sc1/3 , φ) is formulated.