流量变化对中心进气旋转盘平均换热的影响

实际中心进气的气冷涡轮盘被简化成中心进气外缘加热的旋转盘模型,以实验的方法研究了涡轮旋转盘附近冷气在非定常情况下的流动与换热特性,主要是冷气量对盘面温度和盘面的平均努赛尔特数的影响.转盘的有效半径为400 mm,最大转速为3000 r/min,加热功率为1000 W.实验结果表明:盘缘区域温度随时间的变化率大于中心区域温度随时间的变化率;流量的改变,盘面平均努赛尔特数亦随之发生较快的改变;某一工况下对转盘进行加热,稳定后,停止加热,盘面平均努赛尔特数从一个很大的数值逐渐减小,然后再逐渐增大.

Transient Heat Transfer Characteristics of Shrouded Rotating Disk with Unsteady Centric Air Inflow

The transient heat transfer characteristics of a shrouded rotating disk were investigated experimentally as the mass flow rate was changed.The disk diameter was 400 mm and its maximum rotating speed was up to 300 r/min.The disk was heated at rim to simulate the heat conduction from turbine blades.One side of disk was cooled by air and another side was adiabatic.The temperatures of cooling side and heating side were measured synchronously at different time interval.The variation of averaged Nusselt number with non dimensionalized time was obtained.It was found that the averaged Nusselt number enlarged with the increase of inlet mass flow rate,but reached its steady state value rapidly after the change of mass flow rate.