| With the increase of inlet gas temperature in turbine, the investigation of cooling technique for the turbine blade is interested by more and more researchers. The cooling technique of the turbine blade is always one of the key techniques in the aeroengine. In recent years, the film cooling technique is used widely for the turbine blade and the flow field and heat transfer in the turbine is the focus of investigation by worldwide researchers. But for the high-speed rotating turbine, it is very difficult to understand deep. To design the high-powered aeroengine in China, the investigation of cooling technique for the high temperature equipments is necessary to get the first-hand data and perfect the design system of the aeroengine.In the film-cooled turbine, the flow field is very complex with the mixing of the cooling jet and the high-temperature mainstream. When the discrete holes are applied for the film-cooled turbine blade, the flow field in the film-cooled turbine is three-dimensional and highly complex. The flow structures of jet-to-mainstream and jet-to-jet have strong effects on the film cooling effectiveness and the aerodynamics of the turbine. So the investigation of mixing flow field of the jet and the mainstream helps to restrain the cooling jet from penetrating the mainstream, protect the turbine blade from impingement by the high-temperature mainstream and increase the film cooling effectiveness. The flow field and heat transfer in the stationary and rotating turbine with jet on the blade head are investigated through the experimental measurements and numerical simulations in this project, and the effects of rotation, blowing ratio and stator wake on the mixing flow field and heat transfer of the turbine are also analyzed. The data and conclusions from the experimental measurements and numerical simulations are valuable for the design and optimization of the film-cooled turbine blade.Main contents and conclusions of the investigation are described in the following:1. The test facility is designed for the flow field measurement in the turbine model with jet hole on the blade head according to the experimental conditions. The air jet system on the turbine blade model is specially designed for the rotating condition. The satisfactory results are gained from the experimental measurements.2. The three-dimensional flow fields at different blowing ratios in the stationary and rotating turbine are measured with a single slanted hot-wire probe and PIV in different axial and radial planes. The effects of rotation and different blowing ratios(M=1.5, 2.0) on the flow field and the vortex field in the turbine are investigated. Experimental results show the flow field structure with the mixing of the jet and the mainstream, and the kidney vortex pair is generated in the mixing process. Downstream of the jet holes, there is the wake region where the axial velocity loss is generated. Compared with the stationary condition, the rotation makes the mixing flow field flow in the radial direction in the rotating turbine.3. The numerical simulations with NUMECA software are carried out for the above experimental model in the same conditions of the experimental measurements, and the simulations are also compared with the experimental results to validate the reliability of the computational model. The emphases of the numerical simulation are to investigate the flow field near the blade surface, the margin streamline, the mixing energy loss and so on which can't be got in the experimental measurements.4. The results of the experimental measurements and the steady numerical simulations indicate that the effect of rotation on the flow field on the suction side is less than that on the pressure side because of the bigger curvature and acceleratory flow on the head of the suction surface. The centrifugal force and the Coriolis force exist in the flow field of the rotating turbine compared with the stationary turbine, and these forces have different effects on the flow field of the suction and pressure sides from the experimental measurements and numerical simulations. The effect of rotation on the flow field of the pressure side is more distinct than that on the suction side from the measured velocity vectors in Y-Z planes and the radial velocity contours. Also, the mixing energy loss in the rotating turbine is different from that of the stationary turbine because of the change of the mixing flow field.5. The measured flow fields in the rotating turbine at three different rotor-stator phases and the unsteady numerical simulation indicate that the effect of the stator wake on the flow field in the rotating turbine is not neglected. Results indicate that the jet flows up obviously on the pressure side because of the stator wake but less change occurs on the suction side because of the location of jet holes. From the temperature fields of the unsteady numerical simulation, the effect of stator wake makes the film cooling effectiveness on the pressure surface fluctuate certainly at different time, but on the suction surface the change of film cooling effectiveness is less.6. The field synergy principle is used to study the synergy of the velocity vector and the temperature grads field in the stationary and rotating turbine based on the steady numerical simulation, and the changes of v ?? T andθare compared in different conditions. To increase the cooling effectiveness and the performance of the film-cooled turbine, the angle between the velocity vector and the temperature grads,θ, should be kept at about 90 to decrease the heat transfer between the mainstream and the cooling jet. The field synergy principle is confirmed to well evaluate the heat transfer characteristic in the turbine and may be used to direct the design and optimization of the heat transfer in the film-cooled turbine.
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