Investigations On Temperature Uniformity And Heat Transfer Characteristics In Rotating Turbulent Cooling Channel

Gas turbine machine, as a high-tech intensive equipment, has been extensively usedin power generation, marine, aviation and other fields. As a part of its design, the level ofheat transfer design of turbine component limits the total efficiency of turbine machinedirectly, therefore it has significance to developing turbine blade heat transfer technologyfor enhancing heat exchange and improving utilization factor of power. Turbulent coolingas a tool of enhancing heat transfer, has been proved to be an effective method to reduceblades temperature and prolong the working life. Moreover while the temperature islowered, to weaken the negative factor of rotating extra force and to increase temperatureuniformity in turbulent cooling, is beneficial to reduce the blades thermal stress andimprove the reliability. Thus it’s necessary to conduct research in this area.This paper studied the influence of changing the parameter of Reynolds number,rotating number, rotating direction, ribs form and ribs angle to heat transfer in rotating orstatic straight or U-bent channel; researched the effect of rotating extra force to the flowphenomenon; set Nusselt number, flow resistance, synthesize coefficient of heat transfer,temperature uniformity and equivalent stress as standard to evaluate each project.In a straight channel, transforming the ribs induced secondary flow can improve thepoor heat transfer phenomena in the leading edge because of Coriolis force by changingthe ribs angle, and the best angle is45°. To α=45°channels, when rotating directionangle β<90°, the adverse effects can be reduced effectively by reason of Coriolis forcein leading side; when β>90°, the heat transfer is worse and overall heat exchange abilitydrops. The temperature uniformity can be influenced by ribs angle and rotating directionangle: the ribs angle increasing leads temperature uniformity decline; when β=135°temperature uniformity is terrible, and when β turns down, temperature uniformitysignificantly increased.In a U-bent channel, the flow phenomena in inlet-side channel are similar as it in astraight channel, however, the flow phenomena are influenced by turn induced secondaryflow obviously and the role of the Coriolis force is severely weakened. The crosswisetemperature distribution on outside wall is determined by ribs form, and the rotatingnumber influences the lengthways temperature distributions. Each project performs wellon lengthways temperature distributions but terrible on crosswise temperature distribution in static condition. In rotating condition, temperature can be decreasedeffectively and crosswise temperature distribution is improved. Parallel I project performsbest on temperature uniformity in rotating condition.