Alternative Forcing for Homogeneous Isotropic Turbulence in Real Space

An alternative to the linear forcing of Lundgren [1] is suggested for sustaining homogeneous and isotropic turbulence. The method depends on a random pseudo-velocity field produced initially from an arbitrary spectrum. Energy can be fed into a variety of different range of wavenumbers so that the resulting total turbulent kinetic energy remains constant. This talk will first introduce the methodology used to obtain 1D spectra and correlation functions which will then be used to validate the homogeneity and isotropy of the sustained turbulence. The effects of window functions on 1D spectra and correlations will be also addressed. Finally, the effect of initial conditions (i.e. triggering at different wavenumbers) on the statistics, especially spectra and correlation functions will be investigated, with a particular view toward understanding the variety of spectra generated by experiments, e.g., [2,3].\\[4pt] [1] Lundgren, T. S. \ (2003) \ Ann. Res. Briefs, CTR, Stanford\\[0pt] [2] Comte-Bellot, G.\ and Corrsin, S.\ (1971) JFM, 48, 273-337.\\[0pt] [3] Seoud, R.\ and Vassilicos, J.\ C.\ (2007) Phys Flds. 19.