Variational principle based computation of KPP average front speeds in random shear flows

James Nolen Jack Xin

Analysis of PDEs mathscidoc:1912.43909

Methods and Applications of Analysis, 11, (3), 389-398, 2004
Variational principle of Kolmogorov-Petrovsky-Piskunov (KPP) minimal front speeds provides a fast and accurate way for speed calculations. A variational principle based computation is carried out on a large ensemble of KPP random speeds through spatial, mean zero, stationary, Gaussian random shear flows inside two dimensional channel domains. In the regime of small root mean square (rms) shear amplitude, the enhancement of the ensemble averaged KPP front speed obeys the quadratic law. In the large rms amplitude regime, the enhancement follows the linear law. An asymptotic ensemble averaged speed formula is derived and agrees well with the numerics. Related theoretical results are presented with a brief outline of the ideas in the proofs. The ensemble averaged speed is found to increase sublinearly with enlarging channel widths, while the speed variance decreases. Direct simulations in the
No keywords uploaded!
[ Download ] [ 2019-12-24 21:06:01 uploaded by Jack_Xin ] [ 207 downloads ] [ 0 comments ]
@inproceedings{james2004variational,
  title={Variational principle based computation of KPP average front speeds in random shear flows},
  author={James Nolen, and Jack Xin},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224210601777788473},
  booktitle={Methods and Applications of Analysis},
  volume={11},
  number={3},
  pages={389-398},
  year={2004},
}
James Nolen, and Jack Xin. Variational principle based computation of KPP average front speeds in random shear flows. 2004. Vol. 11. In Methods and Applications of Analysis. pp.389-398. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224210601777788473.
Please log in for comment!
 
 
Contact us: office-iccm@tsinghua.edu.cn | Copyright Reserved