Analysis of Unsteady Compressible Viscous Layers

• Published in: Journal of turbomachinery 1991-10, Vol.113 (4), p.644-653
• Main Authors: Power, G. D, Verdon, J. M, Kousen, K. A
• Format: Article
• Language: English
• Subjects: Applied fluid mechanics; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Hydraulic and pneumatic machinery; Physics
• ISSN: 0889-504X; 1528-8900
• DOI: 10.1115/1.2929130

The development of an analysis to predict the unsteady compressible flows in blade boundary layers and wakes is presented. The equations that govern the flows in these regions are transformed using an unsteady turbulent generalization of the Levy–Lees transformation. The transformed equations are solved using a finite difference technique in which the solution proceeds by marching in time and in the streamwise direction. Both laminar and turbulent flows are studied, the latter using algebraic turbulence and transition models. Laminar solutions for a flat plate are shown to approach classical asymptotic results for both high and low-frequency unsteady motions. Turbulent flat-plate results are in qualitative agreement with previous predictions and measurements. Finally, the numerical technique is also applied to the stator and rotor of a low-speed turbine stage to determine unsteady effects on surface heating. The results compare reasonably well with measured heat transfer data and indicate that nonlinear effects have minimal impact on the mean and unsteady components of the flow.