The sealing problems of the labyrinth packing are here dealed with theoretically and experimentally. The principal object of this research is to investigate the effects of the shape of the labyrinth packing, especially of the straight-through type.
In the first chapter, the idealized state change of gas through a labyrinth packing is discussed as a fundament in considering the leakage loss of the labyrinth. In the second chapter, a theoretical consideration on the straight-through type labyrinth packing is introduced. The numerically calculated results of this theory were compared with our experimental results, and it was as certained that they were in good agreement with each other.
The experimental researches on the straight-through type are described in chapter 3. The experiments have been carried out to make clear the effects of the shape of the labyrinth from the various aspects. Some interesting and valuable results have been obtained, and in particular the effects of the depth of the pocket are worthy of note. Namely, it was found that the leakage loss was the smallest when the pocket of the labyrinth was in form of a shallow rectangular groove. This is of advantage not only for the purpose of reduction of the leakage loss, but also from the view point of constructing the labyrinth packing. Moreover, this problem could be illustrated by developing the theory described in chapter 2. In chapter 4, pressure distributions and state changes through the straight-through type are explained as compared with the ideal type described in chapter 1.
Moreover, as the appendixes, the experiments on the idealized labyrinth packing, on the peculiar types and on the staggered type labyrinth packing are respectively explained.
From these investigations we would be able to take the useful data and the principal points to consider the effects of labyrinth packing.
This report is a summary of our investigations on the labyrinth packing and details of them have been successively published in Transactions of Japan Society of the Mechanical Engineers or other publications.