Numerical Study on the Influence of Stator Bolts on Flow and Heat Transfer Characteristics of Centrifugal Compressor Back Cavity
The influence of stator bolts on flow and heat transfer characteristics of centrifugal compressor back cavity was studied using numerical simulation methods.By comparing the two kinds of disk cavity models with and without bolts,the influence law of stator bolts on the swirl coefficient,rotor disk windage torque coefficient and convective heat transfer coefficient of the centrifugal compressor back cavity was an-alyzed.The results show that the original clockwise large vortex in the back cavity will break into multiple small vortices with bolts on stator disk,making the flow in back cavity more complex and irregular.The stator disk bolts mainly affect the swirl coefficient in the low radius range of the disk cavity,resulting in an overall lower swirl coefficient within the non-dimensional radius r/R=0.3～0.75 range compared with smooth back cavity.At low radius positions,stator bolts have an inhibitory effect on the circumferential motion of fluid in the boundary layer,while at high radius positions,the effect of stator bolts is opposite,resulting in a comprehensive increase of about 72.7％in the windage torque coefficient of rotor disk un-der the flow condition of Cw=0.92 × 104 and Reω=1.39 × 106.After installing bolts on the stator disk,the convective heat transfer coefficient of rotor significantly decreases,resulting in a temperature decrease in both the back cavity fluid and rotor disk.
boltscentrifugal compressorback cavityflow and heat transfernumerical simulation
万方数据
维普
