[en] Reynolds equation is an essential tool in the design process of gas bearings. Even though global parameters, such as load capacity and power loss, can be predicted with reasonable accuracy, the accurate prediction of detailed flowfield is a much more significant challenge, particularly for the bearings operating with highly dense gases. However, the experimental with detailed pressure and temperature distributions, particularly operating with dense gases are limited. To evaluate the suitability of turbulence models for performance predictions of gas bearings, this paper uses Reynolds-averaged Navier–Stokes equations to explore flow physics and thermal behaviour of representative flows within gas bearings instead. Three eddy-viscosity models and one Reynolds stress model, namely RNG k − ϵ, Spalart–Allmaras, k − ω SST and RSM-ω, are selected. Numerical simulations of a thrust-type gas bearing are first conducted to highlight the importance of selecting appropriate turbulence models as well as the computational cost. Comparisons are then performed with the available experimental data and high fidelity numerical results, including isothermal and nonisothermal Couette and Poiseuille flows, and flow over the backward step. These are representative flows at the circumferential, radial directions and groove regions of gas bearings. The SST turbulence model with low-Re corrections is recommended to predict the performance of gas bearings in terms of accuracy and computational cost. (paper)