*2.2. Variant B of the Design Method*

Variant B of the design method can be applied when the change of the height of the seal chambers in the flow machine design is possible. This variant consists in changing the pitch lengths according to the Equation (6) without changing the length *LS* and with adapting the height of respective seal chambers to the flow conditions. The application of variant B results in obtaining variable chamber volumes in such a way that chambers are increasing in the direction of the gas flow (Figure 5). Illustrative diagram of the staggered seal geometry after the variant B of the design method was applied, is presented in Figure 5.

**Figure 5.** Diagram of geometry as per the comprehensive design method.

Variable chambers' height is selected so that the height of the last chamber is equal to its length *HC*(*n*) = *LC*(*n*). It was assumed that the variability of chambers' height *HC*(*i*) is linear, which can be described by the dependence:

$$\text{HC}(i) = H + (\text{LC}(n) - H)\frac{i}{n'} \tag{7}$$

where *n* is the number of the seal chambers, *i* = 1, 2, . . . , *n*.

Furthermore, it was assumed that the new geometry has clearances of the same flow field as the initial geometry. Height *H* and diameter *D* of the inlet and of the outlet channels are also the same as in the initial geometry.
