The Leakage of Air Through Radial Labyrinth Glands : On the Straight Through Type

Abstract

A theoretical formula for calculating the leakage is derived taking the carry-over of kinetic energy of the fluid from the preceding throttling into consideration. The carry-over factor in the formula is evaluated from the experimental results obtained by the radial labyrinth glands for compressed air. A consideration for the carry-over is presented assuming that the flow issuing from the throttling fin broadens out proportionally with the radial distance in the expansion chamber, and it is shown that the carry-over factor is a function of the ratio s/δ and the resistance coefficient of the flow that depends on the ratios h/s and δ/h, where s is the width of the chamber, h is the height of the fin and δ is the tip clearance of the fin. The results of the experiment performed to determine the discharge coefficient of a single radial fin are also presented for three distinct types of fin.