Abstract
General turbulent mean statistics are shown to be characterized by a variational principle. The variational functionals, or ``effective actions,'' have experimental consequences for turbulence fluctuations and are subject to realizability conditions of positivity and convexity. An efficient Rayleigh-Ritz algorithm is available to calculate approximate effective actions within probability density function (PDF) closures. Examples are given for Navier-Stokes and for a three-mode system of Lorenz. The new realizability conditions succeed at detecting a priori the poor predictions of PDF closures even when the classical second-order moment realizability conditions are satisfied.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
