Effects of wetness and humidity on transonic compressor of gas turbine

•Effect of fogging on cooling in transonic compressors was numerically investigated.•Causal relation between wetness and particle deposition on blades was clarified.•Moist-air flows through 1.5-stage full annulus blade rows were simulated.•Shock played the leading role in evaporating and cooling the moist air.•Effect of condensation on particle deposition was further investigated.•Fogging and deposition may be in a trade-off relation for the performance.