Toward Better Understanding of Far-field Radiated Noise Mechanisms in a High Reynolds Number Mach 0.9 Axisymmetric Jet

2008 ◽  
Author(s):  
Jeff Kastner ◽  
Jin-Hwa Kim ◽  
Mo Samimy
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Far Field ◽  
Radiated Noise ◽  
Axisymmetric Jet ◽  
High Reynolds

scholarly journals On the boundary layer structure near a highly permeable porous interface

2016 ◽  
Vol 798 ◽  
pp. 88-139 ◽  
Author(s):  
Mohit P. Dalwadi ◽  
S. Jonathan Chapman ◽  
Sarah L. Waters ◽  
James M. Oliver
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Layer Structure ◽  
Three Dimensional ◽  
Interfacial Stress ◽  
Far Field ◽  
Dimensional Problem ◽  
Flow Through ◽  
High Reynolds ◽  
Porous Obstacle

The method of matched asymptotic expansions is used to study the canonical problem of steady laminar flow through a narrow two-dimensional channel blocked by a tight-fitting finite-length highly permeable porous obstacle. We investigate the behaviour of the local flow close to the interface between the single-phase and porous regions (governed by the incompressible Navier–Stokes and Darcy flow equations, respectively). We solve for the flow in these inner regions in the limits of low and high Reynolds number, facilitating an understanding of the nature of the transition from Poiseuille to plug to Poiseuille flow in each of these limits. Significant analytical progress is made in the high Reynolds number limit, and we explore in detail the rich boundary layer structure that occurs. We derive general results for the interfacial stress and for the conditions that couple the flow in the outer regions away from the interface. We consider the three-dimensional generalization to unsteady laminar flow through and around a tight-fitting highly permeable cylindrical porous obstacle within a Hele-Shaw cell. For the high Reynolds number limit, we give the coupling conditions and interfacial stress in terms of the outer flow variables, allowing information from a nonlinear three-dimensional problem to be obtained by solving a linear two-dimensional problem. Finally, we illustrate the utility of our analysis by considering the specific example of time-dependent forced far-field flow in a Hele-Shaw cell containing a porous cylinder with a circular cross-section. We determine the internal stress within the porous obstacle, which is key for tissue engineering applications, and the interfacial stress on the boundary of the porous obstacle, which has applications to biofilm erosion. In the high Reynolds number limit, we demonstrate that the fluid inertia can result in the cylinder experiencing a time-independent net force, even when the far-field forcing is periodic with zero mean.

Active Control of a High Reynolds Number Mach 0.9 Axisymmetric Jet

AIAA Journal ◽  
2009 ◽  
Vol 47 (1) ◽  
pp. 116-128 ◽  
Author(s):  
J.-H. Kim ◽  
J. Kastner ◽  
M. Samimy
Keyword(s):  
Reynolds Number ◽  
Active Control ◽  
High Reynolds Number ◽  
Axisymmetric Jet ◽  
High Reynolds
Sign in / Sign up

Export Citation Format

Share Document