Research on Leakage Control Method of Unidirectional Tesla Annular Seal
To address the working medium leakage problem of turbomachinery static and dynamic gap,a new unidirectional Tesla annular seal was proposed,a three-dimensional model of Tesla annular seal was established,and the influence of Tesla nozzle geometry including axial number,diversion angle,rotation diameter and nozzle diameter and operating parameters including pressure ratio and rotational speed on the seal leakage characteristics was studied by computational fluid dynamics(CFD)method.Results show that the Tesla annular seal can effectively reduce the seal outlet velocity and suppress the seal leak-age flowrate up to 15.7%;the Tesla annular seal has better leakage suppression effect at high pressure ratio and high rotational speed;there is an optimum value for both axial number and nozzle diameter,which makes the Tesla annular seal outlet velocity the smallest and leakage flowrate the lowest;as the di-version angle decreases,the Tesla annular seal outlet velocity and leakage flowrate decrease;a small ro-tary diameter has little impact on the Tesla annular seal outlet velocity and leakage flowrate,but more than two times the diameter of the nozzle will cause the outlet velocity and leakage flowrate to rise slightly.
Tesla annular sealcomputational fluid dynamics(CFD)leakage characteristicsstability