本文首先基于分离变量算法（separation of variables，MSV）求解了单节流孔静压气体轴承的层流边界层方程，研究了节流孔附近流场特性，阐明了节流孔出口附近压降现象是由于惯性效应导致的原因，并研究了轴承几何参数和供气参数对压降现象的影响规律。最终提出了压降现象产生的临界条件为压比为0.9409，也即压比大于临界压比时，压降现象消失。其次基于质量流量相等原则，结合层流边界层的MSV方法及雷诺方程的解析算法，提出了一种计算节流孔系数的新方法，并研究了轴承的几何参数及供气参数对节流孔系数的影响规律。结果显示，节流孔系数存在着参数敏感和不敏感区域，这是由于当压比小于等于0.6左右时，节流孔系数趋近于一个常数0.86左右导致的。
Abstract
In this paper, the method of “separation of variables” (MSV) is utilized to solve laminar boundary-layer equations of aerostatic thrust bearing with single orifice and study the performances of the flow field behind orifice. Then the pressure depression phenomenon is caused by the inertial effect and the influences of the aerostatic bearing geometry and flow parameters on the pressure depression are studied. Moreover, the critical condition of the pressure phenomenon generation is the critical pressure ratio 0.9409, i.e. that is, when the pressure ratio is greater than the critical pressure ratio, the pressure depression phenomenon disappears. Moreover, based on the principle of the equal mass flow rate, a new numerical method which combines the MSV for solution of laminar boundary-layer equations and analytical solution of Reynolds equation is proposed to study the discharge coefficient. The influences of flow and geometry parameters on discharge coefficients are investigated. The results show that there exists parameters insensitive and sensitive regions in discharge coefficient analysis, which is caused by that discharge coefficient tends to be constant 0.86 when pressure ratio is approximately less than 0.6.
关键词
静压气体止推轴承 /
压降现象 /
节流孔系数 /
分离变量算法 /
雷诺方程
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Key words
Aerostatic thrust bearing /
Pressure depression /
Discharge coefficient /
MSV /
Reynolds equation
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