Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations

Details Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations

2010-06-23

arxiv.org/abs/1006.4598v1

J. Fluid Mech. (2010), vol. 663, pp. 100-119

Physics

Fluid Dynamics

To appear in J. Fluid Mech

Scientific paper

10.1017/S002211201000340X

This work builds on and confirms the theoretical findings of Part 1 of this paper, Moarref & Jovanovi\'c (2010). We use direct numerical simulations of the Navier-Stokes equations to assess the efficacy of blowing and suction in the form of streamwise traveling waves for controlling the onset of turbulence in a channel flow. We highlight the effects of the modified base flow on the dynamics of velocity fluctuations and net power balance. Our simulations verify the theoretical predictions of Part 1 that the upstream traveling waves promote turbulence even when the uncontrolled flow stays laminar. On the other hand, the downstream traveling waves with parameters selected in Part 1 are capable of reducing the fluctuations' kinetic energy, thereby maintaining the laminar flow. In flows driven by a fixed pressure gradient, a positive net efficiency as large as 25 % relative to the uncontrolled turbulent flow can be achieved with downstream waves. Furthermore, we show that these waves can also relaminarize fully developed turbulent flows at low Reynolds numbers. We conclude that the theory developed in Part 1 for the linearized flow equations with uncertainty has considerable ability to predict full-scale phenomena.

Affiliated with

Also associated with

No associations

Rating

Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlling the onset of turbulence by streamwise traveling waves. Part 2. Direct numerical simulations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-278502