(250c) Nonlinear Instability of Resonance in Thin Films with Patterned Walls: Theory and Experiments

Parametric resonance of a fluid on a corrugated wall is analyzed both numerically and experimentally. This work is motivated by its applications to thermal management in microgravity where patterned walls and resonant interactions can enhance heat transfer and delay dry out. A reduced order model based on the long-wave WRIBL theory (Weighted Residual Integral Boundary Layer) (Kalliadasis et al., 2012) is developed to track the nonlinear evolution of the interface when a bilayer is subject to mechanical vibrations. The evolution equations are linearized to determine the stability threshold for the onset of the instability. The threshold character is compared with experiments that use silicone oil and FC70 as working fluids. The predictions compare qualitatively well with experiments.

Acknowledgment: Support from NASA NNX17AL27G, NASA 80NSSC18K1173 and FSGC-08 TO No NNX15_023 are gratefully acknowledged.

References:

Kalliadasis, S., Ruyer-Quil, C., Scheid, B., & Velarde, M. G. (2012). Falling liquid films. Springer Science & Business Media (Vol. 176).