Micro Surface-roughness Effect on the Flow Induced by Rotating Disk

다국어 초록 (Multilingual Abstract)

An analytic study has been made of the slip velocity over rotating disk with micro surface roughness. The system Ekman number, E≡V/ΩR², is assumed to be very small value, in which  denotes kinematic viscosity of the fluid, Ω rotational angular velocity of the disk and  radius of the disk. Amplitude of the surface roughness, δ, which is a characteristic length scale of roughness, is equal to or less than the thickness of Ekman boundary layer, i.e., δ≤O(E<SUP>1/2</SUP>). Implementing a strained coordinate method to the Ekman layer flow, the flow field solutions are obtained as a form of explicit formula, and then effective slip velocity conditions are clearly defined on the geometrical mean plane. The results are confirmed by comparing with numerical data. Several in-depth physics underlying the solution are discussed.

목차 (Table of Contents)

• ABSTRACT
• 1. INTRODUCTION
• 2. MATHEMATICAL FORMULATION
• 3. ANALYSIS
• 4. Asymptotic solution, E→0
• 5. CONCLUSIONS
• ACKNOWLEDGEMENT
• REFERENCES