Entropy Generation through Deterministic Spiral Structures in a Corner Boundary-Layer Flow

Entropy

LaVar King Isaacson¹  Morin Celine¹  Bernard Desmet¹ 

[1] Mechanical Engineering, University of Utah, 2067 Browning Avenue, Salt Lake City, UT 84108, USA; E-Mail

关键词: corner boundary-layer flows;    deterministic spiral structures;    empirical entropies;    fractal intermittency exponents;    entropy generation;   

DOI  :  10.3390/e17085304

来源: mdpi

【 摘 要 】

It is shown that nonlinear interactions between boundary layers on adjacent corner surfaces produce deterministic stream wise spiral structures. The synchronization properties of nonlinear spectral velocity equations of Lorenz form yield clearly defined deterministic spiral structures at several downstream stations. The computational procedure includes Burg’s method to obtain power spectral densities, yielding the available kinetic energy dissipation rates within the spiral structures. The singular value decomposition method is applied to the nonlinear time series solutions yielding empirical entropies, from which empirical entropic indices are then extracted. The intermittency exponents obtained from the entropic indices allow the computation of the entropy generation through the spiral structures to the final dissipation of the fluctuating kinetic energy into background thermal energy, resulting in an increase in the entropy. The entropy generation rates through the spiral structures are compared with the entropy generation rates within an empirical turbulent boundary layer at several stream wise stations.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.