Dynamics and Simulation of Head-Medium Interface in Magnetic Storage Systems

为了分析头部-介质界面问题中最值得关注的头部碰撞现象，实现了精确测量飞头动态特性的实验装置，建立了能够在超薄空间内模拟飞头动力学的分析方法。实验装置：利用新设计的高刚度气轴、空气循环除尘系统和振动控制台等实验装置，验证了飞头在0.03微米以下的稳定飞行状态。利用基于激光干涉测量的间距测量系统，实现了1~2 nm的高精度和0.03微米的最小测量极限，成功地消除了光束光斑中的干涉条纹和激光输出中的共振噪声。分析方法：平均油膜厚度理论倾向于在滑移流区具有表面粗糙度的气体润滑。一个简单的…推导了更多的IED平均雷诺方程，并通过与实验结果的比较，验证了该方程在确定滑移流区表面粗糙度效应时的适用性。数值研究了粗糙度作用下润滑膜的可压缩性对平均油膜厚度的影响，得到了各向异性油膜厚度与粗糙度方向相关的一般形式的平均静态和动态润滑方程。通过求解这些方程，给出了存在于计算机飞头和纹理介质之间的润滑膜的动态特性。演示了磁头滑块在凸起上方飞行的瞬时响应，表明了粗糙度方向和粗糙度运动的影响。值得注意的是，纵向粗糙度起到降低阻尼系数的作用，而对移动的横向粗糙度有相反的影响。因此，对于纵向粗糙度而言，滑块在凸起上方的即时漂移最小，而对于移动的横向粗糙度而言，残余振动的衰减速度最大。较少

TO analyze the head crash phenomena, which are the most significant concern in the head-medium interface problem, experimental apparatus for accurately measuring flying head dynamic characteristics was realized, and analytic methods which enable to simulate the flying head dynamics in a ultra thin spacing were established.1. Experimental apparatus: Stable flying operation of a flying head down to 0.03 mum was confirmed using newly designed experimental apparatus, which comprises high stiffness air spindle, air circulating dust filtering system and vibration control table. A high accuracy of down to 1 or 2 nm and a minimum measurement limit of 0.03 mum were achieved utilizing spacing measurement system based on laser interferometry which successfully eliminated undesirable interference fringes in beam spot and resonance noise in laser output.2. Analytic method: The average film thickness theory was tended to gas lubrication possessing surface roughness in the slip flow regime. A simplif … More ied averaged Reynolds equation was derived and its applicability to determining the surface roughness effects in the slip flow regime was confirmed through comparing with experiments. The compressibility effects of lubricating films incurring a roughness on film thickness averaging were studied numerically.Averaged static and dynamic lubrication equations were derived in the general form containing anisotropic film thickness dependent on roughness orientation. Solving these equations leads to a presentation of the dynamic characteristics of lubricating films existing between computer flying heads and textured media. Transient responses of head sliders flying over a bump were demonstrated indicating the effects of roughness orientation and roughness movement. It is interesting to note that longitudinal roughness serves to de crease damping coefficients and inversely affects moving transverse roughness. Thus, slider excursion immediately flying over a bump is minimum for longitudinal roughness and the damping speed of residual vibration is maximum for moving transverse roughness. Less