Self-optimizing seal for turbomachinery, and associated systems and methods

A seal system for turbomachinery, wherein the seal system comprises a ring element encircling an axis, wherein the ring element comprises:

• a radially inward surface;
• a radially outward surface;
• a back side extending between the radially inward surface and the radially outward surface;
• and
• a front side positioned opposite the back side and extending between the radially inward surface and the radially outward surface, wherein the front side is positioned to contact a revolving surface of the turbomachinery;
• wherein:
• the front side comprises a stepped surface having two or more steps, wherein the two or more steps comprise a first step positioned farther from the back side than a second step;
• each step comprises a sealing surface positioned along the axis at a location that is different from a sealing surface of each other step;
• each sealing surface is configured to contact the revolving surface, wherein contact between the revolving surface and the sealing surface is within a sealing area;
• each sealing surface comprises a sealing area that is different from a sealing area of each other sealing surface of the two or more steps;
• the seal system further comprises a closing area sized with respect to a face area according to a balance ratio which changes between 0.5 and 1.2 as each step wears away during operation of the turbomachinery, wherein the balance ratio is expressed as a ratio of the closing area, receiving a closing force between the ring element and the revolving surface, with respect to the face area of contact between the front side and the revolving surface;
• a portion of the radially inward surface on the first step is positioned radially outward relative to a portion of the radially inward surface on the second step;
• and
• a portion of the radially outward surface on the first step is positioned radially inward relative to a portion of the radially outward surface on the second step.