David Batchelor

Scalar variance decay in chaotic advection and Batchelor-regime turbulence.

The decay of the variance of a diffusive scalar in chaotic advection flow (or equivalently Batchelor-regime turbulence) is analyzed using a model in which the advection is represented by an inhomogeneous baker's map on the unit square. The variance decays exponentially at large times, with a rate that has a finite limit as the diffusivity kappa tends to zero and is determined by the action of t...

Advection of Passive Tracers in the Atmosphere: Batchelor Scaling

Extensive numerical experiments are performed on tracer dispersion in global reanalysis wind fields. Particle trajectories are computed both along an isobaric (500hPa) and an isentropic (315K) surface in a time interval of one year. Besides mean quantities such as advection of the center of mass and growth of tracer clouds, special attention is paid to the evaluation of particle pair separation...

Anomalous scaling for a passive scalar near the Batchelor limit

A class of phenomenological Hopf equations describing mixing of a passive scalar by random flow close to the Batchelor limit ~i.e., advection by random strain and vorticity! is analyzed. In the Batchelor limit multipoint correlators of the scalar are constructed explicitly by exploiting the SL (N ,R) symmetry of the Hopf operator. Hopf equations close to this ‘‘integrable’’ limit are solved via...

David Thaw

David Foster

Research Interest:-Cancer Biology The goal of our research effort is to understand the biology of cancer cells. From an understanding of the defects in a cancer cell, rational strategies for treatment can be developed.