2R1: The size of the pocket must be as small as possible to make the bearing less sensitive to instability. The minimal value of R1 is limited by Ac.

h0: A high axial bearing stiffness, self-aligning capability and the minimal flow is obtained with small film thickness. The minimal value of the film thickness is limited by bearing deflections and flatness of the bearing surface and is usually related to the bearing size.

Ac: The pressure drop over passage A1 of the simple orifice restrictor is more than four times higher than that over the annulus area A3 when Ac>1 (Fig 12.2 of the book).