NURBS-based IGA of viscous fluid movement with special-shaped small gaps in hybrid bearing

This paper attempts to solve the Reynolds equation of the lubrication problem in hybrid bearing using high-order isogeometric analysis method. The analysis model consists of two parts: the static characteristic calculation part composed of oil film static pressure distribution, oil film thickness and oil film bearing capacity; the dynamic characteristic calculation part including damping coefficient and stiffness coefficient. A mapping strategy based on NURBS basis function is used to realize the application of imposed Dirichlet condition inside the analysis domain of hybrid bearing lubrication characteristics. The analysis of hybrid bearing in fast reactor with complex dynamic and static pressure oil cavity structure shows that: (1) In high-order isogeometric calculation framework, imposed boundary conditions are applied accurately, and dynamic and static characteristics calculation results are given; (2) Compared with the finite element method, when using high-order isogeometric analysis method to solve the viscous fluid motion, the solution requires fewer degrees of freedom to achieve grid independence, and the computational efficiency is also improved in terms of time.