Predictions of scalar mixing and the scalar dissipation rate from large-eddy simulations of a piloted nonpremixed methane/air diffusion flame (Sandia flame D) using the Lagrangian-type flamelet model are presented. The results obtained for the unconditionally filtered scalar dissipation rate are qualitatively compared with general observations of scalar mixing from experiments in non-reactive a...

The mixing of air jets into hot, fuel-rich products of a gas turbine primary zone is an important step in staged combustion. Often referred to as “quick quench,” the mixing occurs with chemical conversion and substantial heat release. An experiment has been designed to simulate and study this process, and the effect of varying the entry angle (0°, 22.5°, and 45° from normal) and number of the a...

We investigate whether angular momentum transport due to unstable pulsation modes can play a significant role in the rotational evolution of massive stars. We find that these modes can redistribute appreciable angular momentum, and moreover trigger shear-instability mixing in the molecular weight gradient zone adjacent to stellar cores, with significant evolutionary impact.

The possible role of magnetic flux tubes in transporting matter from near the H shell through the radiative zone and into the convective envelope is explored. It is shown that the required rates of mass transport necessary to provide nuclear processed material to the envelope can be achieved if large magnetic fields are present just above the H shell in AGB and RGB stars. The required fields in...

This article investigates the modeling of mixing phenomena occur at unsteady stirring conditions in that agitated vessels. In particular, a new model of a torus reactor including a well-mixed zone and a transport zone is proposed The originality of the arrangement of ideal reactors developed here is due to the time-dependent location of the boundaries between the two zones. This concept is appl...

0017-9310/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.ijheatmasstransfer.2010.01.017 * Corresponding author. Tel.: +1 775 784 4986; fax E-mail addresses: [email protected] (F. Su Tyler), [email protected] (A.E. Childress). A fully coupled two-dimensional, numerical model that evaluates, for the first time, the effects of doublediffusive convection in the thermal performance and stabi...

Recent genomic studies have highlighted the important role of admixture in shaping genome-wide patterns of diversity. Past admixture leaves a population genomic signature of linkage disequilibrium (LD), reflecting the mixing of parental chromosomes by segregation and recombination. These patterns of LD can be used to infer the timing of admixture, but the results of inference can depend strongl...

Low-mass stars, ∼ 1 − 2 solar masses, near the Main Sequence are efficient at producing He, which they mix into the convective envelope on the giant branch and distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the observed cosmic abundance of He with the predictions of Big Bang nucleosynthesis. In this paper we find, by modeling a...

Despite being the largest High Nitrate Low Chlorophyll (HNLC) region, the Southern Ocean sustains phytoplankton blooms through the summer, when presumably there is sufficient light, but nutrients in the euphotic zone have been depleted. Physical processes that can potentially supply nutrients from subsurface waters to the euphotic zone, and promote phytoplankton growth in the summer, have not b...

A two-phase ow model for an acceleration-driven compressible uid mixing layer is applied to an initially planar/cylindrical/spherical uid connguration. A conservative form of the one-dimensional compressible equations is derived under the assumption that the uid concentration is continuous. With a hyperbolic conservation law for the concentration gradient, the model supports traveling discontin...