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In order to obtain the effect of endwall secondary flow on the swirling film cooling, a geometric model of cascade is established to research the endwall swirling film cooling and swirling flow induced by prismatic jet impingement configurations. Numerical simulation is applied to investigate three jet flow configurations on the endwall film cooling performance at the compound angles of film hole γ = 0° and 30° and blowing ratios M = 0.5–2.0. The influence of complex vortex structures near endwall for jet flow is analyzed in detail; the strong transverse cross flow near the endwall is the main reason affecting the film cooling effectiveness. The variation laws of endwall film cooling effectiveness with the compound angle of film hole, jet flow configuration, and the blowing ratio are obtained. As the blowing ratio increases, the spanwise average film cooling effectiveness increases first and then decreases. While the blowing ratio is M =1.0, the endwall film cooling effectiveness is the best. Increasing the compound angle of the film hole leads to a decrease in the endwall cooling effectiveness. The spanwise average cooling effectiveness of γ = 30° decreases by 35% compared to the γ = 0°. [ABSTRACT FROM AUTHOR]

In this study, the thickness of water film, which is frequently formed on compressor blade surface, was investigated. Simultaneously, its movement and extra torque demand were provided by a simulation model of the code. Having taken into account the transformation in blade's profile and the thickness feature of the films, the working medium characteristic transformation in compressor stage was analyzed. In addition, formation, development and movement of the water film on a compressor stage were simulated by using unsteady numerical methods in various water injected conditions. Movement characteristics of water droplets in cascade were investigated to understand the flow mechanisms responsible for water film formation process. The forming and the tearing process of water films, which formed on the blade surface, were analyzed at different injection conditions. In consideration of the "Scoop effect" in actual situation, the maximum quantity of injected water can reach 12 %. Results indicated that continuity and region of the film would be developed with the increment of droplet size and injection rate. It was also found that water film's tearing process brought about flow losses near blade surface due to the increment of surface roughness. [ABSTRACT FROM AUTHOR]

In this paper, a hexagonal prism inlet chamber is used to form a swirling flow for the film cooling, and three kinds of compound angle of film hole (γ = 10°, 20°, 30°) with clockwise swirling or counterclockwise swirling are used for numerical simulation studies. The influence of different compound angles of film hole and the swirling directions for the film cooling effectiveness are obtained. The results show that the film cooling effectiveness and spanwise cooling coverage range of the clockwise swirling or counterclockwise swirling flow both are low when the compound angle of film hole is 10°. With the increasing compound angle of film hole, the kidney shaped vortex of film hole exit gradually weakens until it disappears, which reduces the entrainment effect by the coolant jet. So that the spanwise coverage range of two swirling modes is obviously improved. When the compound angle of film hole is 30° compared to 10°, the average spanwise film cooling effectiveness of clockwise swirling and counterclockwise swirling are increased by about 133.75 and 212.6%, respectively. The average spanwise film cooling effectiveness on the downstream of film hole for counterclockwise swirling is increased by about 140% compared with clockwise swirling. [ABSTRACT FROM AUTHOR]