Effect of molecular rarefaction on head tape interface in a linear tape drive

Purpose - This paper aims to investigate analytically the air bearing pressure and film spacing of the linear head tape interface by numerical iterations between the one-dimensional compressible Reynolds and Bernoulli tape equations.Design methodology approach - In order to account for the molecular rarefaction effect of the ultra-thin gas lubrication, the pressure flow rate with three optimal adjustable coefficients was implemented into the steady state Reynolds equation. Using the central finite difference approach, the two coupled nonlinear equations can be discretized and numerically solved. To speed up the convergence of the tape position to be obtained, a fictitious stiffness was implied during the process.Findings - By comparison with the Talke's first order model, the differences are significant and cannot be neglected. A smaller film spacing of head tape can be acquired by a lower tape speed or a higher tape tension, while the slot edge defect and stain will effectively lower the built-up pressure, thus decreasing the recording density and data access efficiency.Originality value - Incorporating the high-order slip-flow model into the modified Reynolds equation and coupled with the Bernoulli tape deflection equation, this study proposes a feasible approach to the analysis of molecular rarefaction effect on head tape interface in a linear tape drive.