An adaptive modeling method for multi-throttle aerostatic thrust bearing

Abstract

For searching higher carrying capacity of aerostatic thrust bearing (ATB), micro-structures such as recesses and grooves have been recently used to solve the mutual tradeoff between carrying capacity and air film stability. In order to obtain the quantitative relationship between the micro-structure and the carrying capacity, this paper puts forward a mesh adaptation method for small size multi-throttle ATB with micro-structure and thin air film. Contrary to previous methods that lessened or even ignored them, the dimensionless thickness y+ pertaining to the depth is transformed and incorporated into each grids. The adaptation procedures employ the y+ as a variable to refine local mesh quantitatively, meeting the requirements of enhanced wall treatment (EWT) for further turbulence calculation by finite volume method (FVM). By mesh adaptation method, 4 parameters of the micro-structure are studied quantitatively to obtain the regulation of their effects on the carrying capacity and discharge coefficient. By means of previous experimental results, the effectiveness of the mesh adaptation method is verified in this paper. In addition, the obtained discharge coefficient from adaptation could be employed to improve traditional analytical method, making it applicable for small size multi-throttle ATB and available to reflect the effects of micro-structure on carrying capacity.