Parametric investigation of inlet flow cooling on axial compressor performance in different operating conditions

Using the wet compression method improves the gas turbines' performance. It has been successfully incorporated into numerous industrial gas turbines within the power generation sector industry in recent years. The study focuses on the numerical simulation of fluid flow and the application of both dry and wet compression techniques in an axial compressor, specifically The National Aeronautics and Space Administration Rotor 37. The study investigates the impact of key parameters in the wet compression process, such as particle diameter and injection mass flow rate. The flow simulation within the compressor was conducted using the software ANSYS CFX using a stable and three-dimensional method. In wet compression, the discrete phase transition model was used, along with the application of active input forces from the continuous phase. The simulation results for dry and wet compression states were compared with experimental data, showing good agreement. The findings indicated that, under design conditions and near-stall, reducing the droplet size and increasing the injection mass flow rate significantly decreased the static temperature of the outflow. Therefore, it is not recommended to use this method in the operational conditions of choking in the compressor. The study revealed that the maximum stall margin is associated with the dry compression process, and injection reduces the stall margin in all conditions. The largest drop of 5.62% at the edge of the stall occurred with 1 μm droplets at an injection mass flow rate of 3%. Furthermore, the adiabatic efficiency saw its most significant rise with 1 μm droplets, showing a peak increase of 7.21% during near-stall conditions with a 3% mass flow rate. The compressor stable performance range was associated with an 18.31% decrease for 1 μm droplets at an injection rate of 3%.