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The one-dimensional turbulence (ODT) model, formulated in an Eulerian reference frame, is applied to a temporally-evolving premixed turbulent hydrogen plane-jet flame and results are compared with direct numerical simulation (DNS) data. This is the first published study to perform direct comparisons of ODT to DNS for premixed flames. The ODT model solves the full set of conservation equations for mass, momentum, energy, and species on a one-dimensional domain corresponding to the transverse jet direction. The effects of turbulent mixing are modeled via a stochastic process, while the full range of diffusivereactive length and time scales are resolved directly on the one-dimensional domain. A detailed chemical mechanism for hydrogen combustion consisting of 9 species and 21 reactions and a mixture-averaged transport model are used (consistent with the DNS). Cases with two different Damköhler numbers are considered and comparisons between the ODT and DNS data are shown with respect to flow dynamics and thermochemistry. The ODT compared favorably with the DNS in terms of the overall entrainment as judged by the streamwise velocity profile and in terms of local flamelet structure as judged by progress-variable conditional reaction and scalar dissipation rates. While the ODT agreed qualitatively with the overall flame evolution, the net fuel consumption rate was somewhat over-predicted for a brief early period and under-predicted later on, leading to an overly long flame burnout time. It was demonstrated that adjusting a parameter controlling the selection of large eddies improved the prediction of the peak fuel consumption rate and overall reaction progress but worsened the prediction of jet entrainment. An analysis of the 1D nature of ODT is presented that suggests the FSD in ODT needs to be much higher than the FSD in Flow Turbulence Combust the DNS in order to achieve the same overall burning rate, suggesting that the FSD is underpredicted by a significant fraction. While the success of the ODT in reproducing many of the salient features of nonpremixed flames has been demonstrated, the current study suggests that improvements are needed when applied to premixed flames. It is also important to note that the DNS required approximately 40 × 10 6 CPU hours while the ODT required approximately 10 3 CPU hours.

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DOI: http://dx.doi.org/10.3126/ije.v4i2.12666 International Journal of Environment Vol.4(2) 2015: 394-412

examine the effect of salt conditions on some growth attributes and chlorophyll fluorescence in 10 Sugar Beet genotypes. Sugar beet plants were irrigated with saline water, with different levels of conductivity. Results indicated that all the studied growth attributes such as leaf area, leaf number, relative growth rate, and net assimilation rate were decreased in salinity stress conditions. The findings indicated that salinity caused a decrement of light utilization through increased values of fluorescence origin, decreased values of fluorescence maximum, and maximum yield of quantum in photosystem-II. Genotypes exhibited different behavior