A novel method for calculating the dynamic force coefficients of Gas Foil Bearings and its application in the rotordynamic analysis

A comparison of modal analyses of foil-air bearing rotor systems using two alternative linearisation methods

“…It is noted that this paper's finding regarding the LFCM's performance in Case A1 is supported by a paper [21] that has been published during the review of the present paper. Whereas the present paper follows the classical formulation of the LFCM (as in [19,13,11]), the work in [21] proposes a different manipulation of the LFCM and the eigenvalue analysis is limited to OIS determination rather than full modal analysis and Campbell diagrams.…”

“…It is noted that this paper's finding regarding the LFCM's performance in Case A1 is supported by a paper [21] that has been published during the review of the present paper. Whereas the present paper follows the classical formulation of the LFCM (as in [19,13,11]), the work in [21] proposes a different manipulation of the LFCM and the eigenvalue analysis is limited to OIS determination rather than full modal analysis and Campbell diagrams. In addition to Case A1, applicability to Case A2 is illustrated in [21] using a similar bilinear foil model, but the results for this case are not verified against Jacobian-based linearisation or TNDA of the fully-coupled system.…”

“…In addition to Case A1, applicability to Case A2 is illustrated in [21] using a similar bilinear foil model, but the results for this case are not verified against Jacobian-based linearisation or TNDA of the fully-coupled system. Hence, the LFCM's inability to detect pad flutter instability of SEC II of Case (Figure 6b) is not reported in [21].…”

“…The work of this paper follows the common assumption (e.g. [11,15,16,19,21]) that neglects variation in foil deflection with axial position i.e.…”

“…Whereas the present paper follows the classical formulation of the LFCM (as in [19,13,11]), the work in [21] proposes a different manipulation of the LFCM and the eigenvalue analysis is limited to OIS determination rather than full modal analysis and Campbell diagrams. In addition to Case A1, applicability to Case A2 is illustrated in [21] using a similar bilinear foil model, but the results for this case are not verified against Jacobian-based linearisation or TNDA of the fully-coupled system. Hence, the LFCM's inability to detect pad flutter instability of SEC II of Case (Figure 6b) is not reported in [21].…”