On the instability of Ekman boundary-layer flow over a rough disk with a wavy surface profile

Küçük Resim Yok

Tarih

2020

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Wiley

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

We apply the method of lines and the backward difference method to solve highly nonlinear governing mean flow equations of the Ekman boundary-layer flow over a rough disk with a wavy surface profile. These equations are derived using the YHP roughness model that imposes a wavy surface profile in terms of the radial position r, assuming rotational symmetry. Our main interest is to determine the effect of roughness on the local linear convective instability of the Ekman flow, and we solve the local linear stability equations of the disturbances stationary relative to the disk using the Chebyshev polynomials. The crossflow and viscous types of instability modes, the Type I and Type II modes respectively, are analyzed. Our theoretical findings prompts that an adequately designed rough disk can be a useful tool for a passive flow-control method for the Ekman flow. The underlying physical mechanisms are investigated applying a fundamental energy analysis.

Açıklama

Anahtar Kelimeler

Ekman flow, linear convective instability, rotating disk flows

Kaynak

Numerical Methods For Partial Differential Equations

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

37

Sayı

2

Künye