Turbulent flow statistics at Constant Power Input (CPI) with and without drag reduction

        STATISTICS OF TURBULENT CHANNELS WITH AND WITHOUT 
             DRAG REDUCTION AT CONSTANT POWER INPUT

This database features:

• high quality turbulent flow statistics for canonical channel flows driven at
  Constant Power Input (CPI), Constant Flow Rate (CFR) and Constant Pressure
  Gradient (CPG)

• global energy budgets and single point Reynolds stress budgets of turbulent
  channels driven at CPI in their canonical state or in a drag-reduced state
  achieved via spanwise wall oscillations or opposition control

• a comprehensive study of several predetermined and feedback active strategies
  for turbulent drag reductions in channel, comprising parametric studies of the
  increase in energy efficiency for different values of several control parameters

Acknowledgment:

Support through the Deutsche Forschungsgemeinschaft (DFG) project FR2823/5-1 is
gratefully acknowledged. Computing time has been provided by the computational
resource ForHLR Phase I funded by the Ministry of Science, Research and the Arts,
Baden-Württemberg and DFG.

References:

• D. Gatti, A. Cimarelli, Y. Hasegawa, B. Frohnapfel & M. Quadrio,
  (2018) "Global energy fluxes in turbulent channels with flow
  control", Journal of Fluid Mechanics, Vol. 857, pag. 345-373,
  doi: doi.org/10.1017/jfm.2018.749

• M. Quadrio, B. Frohnapfel & Y. Hasegawa, (2016) "Does the choice
  of the forcing term affect flow statistics in DNS of turbulent
  channel flows?", European Journal of Mechanics B. / Fluids, Vol.
  55, pag. 286-293, doi: doi.org/10.1016/j.euromechflu.2015

• Y. Hasegawa, M. Quadrio & B. Frohnapfel, (2014) "Numerical simulation
  of turbulent duct flows with constant power input", Journal of
  Fluid Mechanics, Vol. 750, pag. 191-209, doi: doi.org/10.1017/jfm.2014.269

• B. Frohnapfel, Y. Hasegawa & M. Quadrio, (2012) "Money versus time:
  evaluation of flow control in terms of energy consumption and
  convenience", Journal of Fluid Mechanics, Vol. 700, pag. 406-418
  doi: doi.org/10.1017/jfm.2012.139

Content:

reference-stats --> statistics of turbulent channels at Retau=200, driven
at Constant Flow Rate (CFR), Constant Pressure Gradient
(CPG) and Constant Power Input (CPI).

energy-budgets --> global energy budgets and single-point Reynolds
shear stress budgets of turbulent channels driven at
Constant Power Input (CPI) with drag reduction
achieved via spanwise wall oscillations (Quadrio &
Ricco, JFM 2004) or opposition control (Choi, Moin &
Kim, JFM 1994).

flow-control-strategies --> parametric studies for finding the maximum theoretical
efficiency of following strategies for turbulent
drag reduction at Constant Power Input (CPI):
StTW-fz: streamwise-travelling waves of spanwise body force
StTW-w : streamwise-travelling waves of spanwise wall velocity
SpTW-fz: spanwise-travelling waves of spanwise body force
SpTW-w : spanwise-travelling waves of spanwise wall velocity
OC-v: opposition control based upon wall-normal velocity
BF-w: near-wall body force damping of spanwise velocity fluctuations

Refer to the readme files in each subdirectory for further information on each
database.

Changelog:

Apr-23-2018: database uploaded

                                             davide.gatti@kit.edu
                                       bettina.frohnapfel@kit.edu
                                       maurizio.quadrio@polimi.it
                                            ysk@iis.u-tokyo.ac.jp
                                      andrea.cimarelli@unimore.it