Abstract
By ideal Brandon cycle, the turbine’s inlet temperature will be raised up, as well as the whole heat efficiency of the system. So far, most cooling approach of turbine blades’ interior is using internal cooling passage collocated with impingement cooling approach. Because that turbine blade operate in high temperature and high rotational speed condition, the Coriolis force must be considered while discussing the heat transfer of internal passage. This research discuss how Coriolis force affect the force convection cooling and impingement cooling inside the passage in rotating condition by experiment. The geometry of the passage is 10 mm x 10 mm square without ribs. The surface heating condition is uniform heat flux; the contents of this research divide into two parts, firstly, discuss the heat transfer effect of Serpentine Passage with three corners in different rotating speed and different inlet Reynolds’ number. Finally, consider Coriolis effect on Impinge surface and discuss the variation of heat transfer effect inside the straight passage with single jet hole in different Reynolds’ number of Impingement Flow and cross flow. By experiment, it reveals that whether it rotates or not, increase inlet Reynolds’ number can raise up the heat transfer effect on passage surface. The corner of Serpentine Passage has better heat transfer effect than straight passage, and it has more heat transfer difference between inside and outside corner surface. In addition, while rotating, Coriolis effect cause heat transfer difference between the surface against the wind and the leeward surface in different flow channels, and due to the increase of rotational speed, the average heat transfer effect also raise up, especially at the downstream of the flow channel. In sum, in the Impingement cooling experiment, the average heat transfer on Heated Target Surface will be better with the increase of the Reynolds’ number of Impingement Flow but will be worse with the increase of rotational speed. It reveals that the Reynolds’ number of cross flow and the increase of rotational speed will make the Impingement Flow slant, restraining the Impingement cooling effect. As a result, In the condition of low Reynolds’ number of cross flow and low rotational speed, cross flow can cause much more increase of average heat transfer on Heated Target Surface, this phenomenon is more obvious in low Reynolds’ number of Impingement Flow.