In this study, the relationship between the inlet relative humidity (RH) condition, heat transfer, and droplet accumulation/motions on gas turbine’s compressor blades involved in enhanced film cooling was investigated. Wet compression has gained popularity as a highly effective way to increase power output for gas turbine systems due to its simple installation and low cost. This process involves injection of droplets into the continuous phase (air with high temperature) of the compressor to reduce the temperature of the flow leaving the compressor and in turn increase the power output of the whole gas turbine system. This study focused on a single stage rotor-stator compressor model; the simulations are carried out using the commercial CFD tool ANSYS (FLUENT). In particular, the study modeled the interaction between the two phases including mass and heat transfer, given different inlet relative humidity (RH) and temperature conditions. The Reynolds Averaged Navier-Stokes (RANS) equations with k–ϵ turbulence model were applied as well as the droplet coalescence and droplet breakup model considered in the simulation. The interaction between the blade and droplets was modeled to address all possible interactions, which include: stick, spread, splash, or rebound. The goal of this study is to quantify the relationship between the RH and the overall heat transfer coefficient, and the temperature on the blade surface.

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A personal bio-aerosol sampler is a self-contained, operation flexible, high-efficient device for indoor air quality (IAQ) and health risk exposure monitoring and measurement. Bio-aerosols such germ-laden viruses, microbial species, airborne microorganisms and volatile organic compounds (VOC) are sucked into the sampler and are deposited on the inner wall surface based on cyclone principal. The major concern with bio-aerosol samplers is the collection efficiency. In this study, we use computational fluid dynamics (CFD) tools to evaluate key design parameters, specifically the inlet tube angle and collection tube inner wall roughness. 3D incompressible turbulent flow is simulated using commercial software ANSYS FLUENT. Reynolds stress model (RSM) is used to investigate the turbulence effect with the following boundary conditions (velocity-inlet boundary condition at inlet, outflow boundary condition at outlet and no slip at walls). The numerical approach for air-aerosol interaction is based on an Eulerian-Lagrangian fluid dynamics framework, where the particles or droplets trajectories are computed in a Lagrangian method (discrete phase element) and then conjugate these particles to the continuous phase in the Eulerian frame. The variation of inlet angle affects the collection efficiency of the cyclone separator. In addition, the flow characterizations with different velocity fluctuation profiles validate the continuous phase model. The development and evolution of the vortex core region for the axial velocity are obtained and evaluated in the simulation of the cyclonic flow.