Abstract:A prediction method based on computational fluid dynamic and dynamic mesh technology was proposed to solve the problem of the porous aerostatic spindle rotation error quantitatively accurate in theory.First of all,the geometric models with different waveform and amplitude were established according to the experimental data based on the frequency and amplitude of the spindle rotor roundness error.Then the N-S equation and Newton’s laws of motion were solved to figure out the influence law of the roundness error on rotary error by FLUENT.The influence of the force of the X/Y direction,velocity distribution,pressure distribution and displacement trajectory of rotor with different waveforms and different amplitudes were studied,and the analysis of the influence law of roundness error on rotation error was achieved.The calculation results showed that the roundness error is the main factor of the rotary errors which deteriorates significantly with the increase of amplitude error and the rotary error caused by even wave is significantly lower than the odd wave.Finally,a high precision rotary error measurement experiment platform was set up to measure the rotation error of the porous aerostatic spindle.The measured rotation error is 50 nm (including the rotation error caused by vertical degree,cylindrical degree,roundness and etc.) and the calculated rotation error is 23 nm,accounting for 46 % of the experimental date.It can be concluded that the roundness error is the main factor affecting the rotation accuracy of the spindle, and the validity and accuracy of the rotary error analysis method are also verified.