Turn - Numerical Study Of Flow And Heat Transfer Characteristics Of The Stator Cavity

Two- and Three-dimensional flow and heat transfer processes inside rotator-stator cavities were numerically studied using FLUENT-CFD software . The computational region was composed of fluid region enclosed by stator and rotator disks,as well as inner and outer shrouds, and solid region ,that is rotator disk.The main research work and results are the following:1) Numerical study was conducted for the flow problem inside a typical rotator-stator cavities with different turbulent models including 1-equation model and high k - model RNG k - model. By comparing the results with relative experiment data, it is shown that RNG k - is more exactly than the other turbulent model..2) The influences of axial inflow position, radial outflow size, rotating Reynold number, non-dimensional mass flowrate and axial inflow angle on the flow and heat transfer characteristics were numerically investigated for a typical rotator-stator cavity with axial inflow, radial inflow and radial outflow . The correlations for Average Nusselt number vs rotating Reynold number or non-dimensional mass flowrate were established. The results indicate that: The high positioned air inflow do good to heat transfer in rotator disk; different size of radial outflow have small effects on flow and heat transfer; the heat transfer near rotating disk increases as rotating Reynold number increases or non-dimensional mass flow rate increases.3) A custom filed function module was complied to study the influence of non-dimensional mass flowrate changed with time in stair shape on flow and heat transfer inside rotator-stator cavity with axial inflow and radial outflow .Average Nusselt number takes on a sharp up-down process when the mass flowrate changes from stabile status as to the following change of flowrate, the average Nuselt number changes greatly in the initial stage and then changes gradually.4) In a pre-swirl rotator-stator cavities with discrete pre-swirl nozzles and blade-cooling entry holes, the influences of pre-swirl angle and flow parameter on the flow and heat transfer characteristics were numerically investigated. The correlation for Average Nusselt number vs rotating Reynold number or non-dimensional mass flowrate were established. The results show that: advantage of per-swirl inflow is the effect of cooling the blade-cooling entry holes; pre-swirl inflow increases heat transfer in rotating disk of pre-swirl chamber; as pre-swirl angle increases,local Nusselt number decreases in pre-swirl chamber; the temperature of stator of inner rotator-stator chamber and per-swirl chamber decreases as rotating Reynold number increases; when the axial mass flowrate maintains constant, heat transfer in the rotating disk of inner rotator-stator cavities doesn't change as per-swirl mass flowrate increases, while heat transfer in the rotating disk of per-swirl chamber increases; when the pre-swirl mass flowrate maintains constant ,change of the axial mass flowrate has effect on the whole cavity.