Structure functions in statistically stationary isotropic turbulence
Akylas Evangelos, Gravanis Elias and Marios Fyrillas
CFE-ERCIM 2010, held 10-12 December, 2010 in London, UK, abstract E751
The physics of the linear forcing of isotropic turbulence, allows for some useful estimates of the characteristic length scales of the turbulence produced during the statistically stationary phase. With such estimates we could practically define uniquely the stationary statistics by means of the box-size of the simulation, the linear forcing parameter and the viscosity of each case. We use such estimations in the Karman Howarth equation and we solve it in terms of the second and third order structure functions using a generalized Oberlack Peters closure scheme. The resulting forms and the respective spectra are in very good agreement with experimental and DNS data. They also provide strong insight into the physical process that produces the statistical stationarity, reflecting the role of the periodic boundary condition in the resulting spectral forms.
Akylas Evangelos, Gravanis Elias and Marios Fyrillas
CFE-ERCIM 2010, held 10-12 December, 2010 in London, UK, abstract E751
The physics of the linear forcing of isotropic turbulence, allows for some useful estimates of the characteristic length scales of the turbulence produced during the statistically stationary phase. With such estimates we could practically define uniquely the stationary statistics by means of the box-size of the simulation, the linear forcing parameter and the viscosity of each case. We use such estimations in the Karman Howarth equation and we solve it in terms of the second and third order structure functions using a generalized Oberlack Peters closure scheme. The resulting forms and the respective spectra are in very good agreement with experimental and DNS data. They also provide strong insight into the physical process that produces the statistical stationarity, reflecting the role of the periodic boundary condition in the resulting spectral forms.