The gas volume fraction method was used to achieve the distribution of the sealing effectiveness of multitooth rim sealing

and the sealing effectiveness varied with the nondimensional sealing flow rate，and finally the correlation of the minimum sealing flow rate was obtained（mainstream Reynold number from 1.42×105 to 3.20×105

rotating Reynold number from 5.27×105 to 1.36×106）. The measurement results of carbon dioxide volume fraction showed that the sealing effectiveness was low at high radius but high at low radius. The changes in the sealing effectiveness with the sealing flow rate agreed well with Owens sealing effectiveness equations

so the sealing characteristic could be predicted

and the experimental results expanded its application scope.