Linear temporal stability analysis on the inviscid sheared convective boundary layer flow

Xiao, Yuan, Lin, Wenxian, and Ding, Junling (2022) Linear temporal stability analysis on the inviscid sheared convective boundary layer flow. Physics of Fluids, 34. 114119.

[img]
Preview
PDF (Accepted Publisher Version) - Accepted Version
Download (2MB) | Preview
[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: https://doi.org/10.1063/5.0123044
 
55


Abstract

A linear temporal stability analysis is conducted for inviscid sheared convective boundary layer flow, in which the sheared instability with stable stratification coexists with and caps over the thermal instability with unstable stratification. The classic Taylor–Goldstein equation is applied with different stratification factors Js and Jb in the Brunt–Väisälä frequency, respectively. Two shear-thermal hybrid instabilities, the hybrid shear stratified (HSS) and hybrid Rayleigh–Bénard (HRB) modes, are obtained by solving the eigenvalue problems. It is found that the temporal growth rates of the HSS and HRB modes vary differently with increased Jb in two distinct wavenumber (~a) regions defined by the intersection point between the stability boundaries of the HSS and HRB modes. Based on Jb,cr where the temporal growth rate of the HSS and HRB are equal, a map of the unique critical boundary, which separates the effective regions of the HSS and HRB modes, is constructed and found to be dependent on Js, Jb, and ~a. The examinations of the subordinate eigenfunctions indicate that the shear instability is well developed in the HSS mode, in which the large vortex structures may prevail and suppress the formation of convective rolls; the shear instability in the HRB mode is either “partly developed” when Jb < Jb,cr or “undeveloped” when Jb > Jb,cr , thus only plays a secondary role to modify the dominant convective rolls, and as Jb increases, the eigenfunctions of the HSS mode exhibit different transitional behaviors in the two regions, signifying the “shear enhancement” and “shear sheltering” of the entrainment of buoyancy flux.

Item ID: 76839
Item Type: Article (Research - C1)
ISSN: 1089-7666
Related URLs:
Copyright Information: © 2022 Author(s).
Date Deposited: 23 Nov 2022 02:39
FoR Codes: 40 ENGINEERING > 4012 Fluid mechanics and thermal engineering > 401209 Hydrodynamics and hydraulic engineering @ 100%
SEO Codes: 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280110 Expanding knowledge in engineering @ 100%
Downloads: Total: 55
Last 12 Months: 23
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page