Closure to “Discussion of ‘The Lomakin Effect in Annular Gas Seals Under Choked Flow Conditions’ ” (2007, ASME J. Eng. Gas Turbines Power, 129 , p. 1143)

Abstract

The authors are grateful for this experimental validation of the negative direct static stiffness of choked annular seals. For performing our own calculations, the mentioned conditions were supplemented by some additional assumptions that are somewhat usual for straight annular seals, namely, an imposed inlet pressure drop coefficient ζinlet and an exit recovery coefficient ζexit=1 (complete pressure recovery). The rotation speed was ω=0, and the flow regime was considered as being nonisothermal with adiabatic walls and Tinlet=20°C. Moody’s friction factor was used with the possibility of bridging transition between laminar and turbulent flow. The employed grid had 16 equally spaced cells in the axial direction and 32 in the circumferential one (Fig. 1).