Soot in combustion simulations

Journal ArticleSoot is the dominant source of radiative heat transfer from most practical flames. A review is presented of historical, empirical modelling approaches for estimating heat flux from fires and flames. These historical methods have drawn on empiricism to address the role of soot while seeking methods for including the multi-scale effects of soot formation and flame structure. Both soot concentration and flame temperature have been seen to be local phenomena with dimensions on the order of the diffusion and chemical (Batchelor) scales of the flame. The correlation between the local soot volume fraction and the local temperature field is needed for determining the radiant heat flux from the flame. By using high performance computers (hundreds to thousands of processors) Large Eddy Simulations (LES) can resolve structures on the scale of the pool diameter in pool Hires. Thus, air engulfment and visible flame structure are resolved. Manifolds for the gas-phase chemistry, soot formation, particle growth, soot diffusive/ thermophoretic transport are used to bridge the Batchelor and resolved (LES) scales

Scheduling aircraft landings - the static case

This is the publisher version of the article, obtained from the link below.In this paper, we consider the problem of scheduling aircraft (plane) landings at an airport. This problem is one of deciding a landing time for each plane such that each plane lands within a predetermined time window and that separation criteria between the landing of a plane and the landing of all successive planes are respected. We present a mixed-integer zero–one formulation of the problem for the single runway case and extend it to the multiple runway case. We strengthen the linear programming relaxations of these formulations by introducing additional constraints. Throughout, we discuss how our formulations can be used to model a number of issues (choice of objective function, precedence restrictions, restricting the number of landings in a given time period, runway workload balancing) commonly encountered in practice. The problem is solved optimally using linear programming-based tree search. We also present an effective heuristic algorithm for the problem. Computational results for both the heuristic and the optimal algorithm are presented for a number of test problems involving up to 50 planes and four runways.J.E.Beasley. would like to acknowledge the financial support of the Commonwealth Scientific and Industrial Research Organization, Australia

Some remarks on the hyperelliptic moduli of genus 3

In 1967, Shioda \cite{Shi1} determined the ring of invariants of binary octavics and their syzygies using the symbolic method. We discover that the syzygies determined in \cite{Shi1} are incorrect. In this paper, we compute the correct equations among the invariants of the binary octavics and give necessary and sufficient conditions for two genus 3 hyperelliptic curves to be isomorphic over an algebraically closed field $k$, $\ch k \neq 2, 3, 5, 7$. For the first time, an explicit equation of the hyperelliptic moduli for genus 3 is computed in terms of absolute invariants.Comment: arXiv admin note: text overlap with arXiv:1209.044

Air layering in cassia (Cinnamomum aromaticum Nees.)

Air layering in 2 year old cassia plants (Cinnamomum aromaticum) is reported for the first time. A success of 87.5 and 50.0% rooting was obtained when carried out during July and November, respectively, with 100% field establishment. &nbsp

Rooting response of elite cinnamon (Cinnamomum verum Bercht & Presl.) lines

Rooting of terminal cuttings of cinn amon (Cinnamomum verum) with indole butyric acid 2000 ppm was standardi zed. Nine elite lines of cinn amon, superior in their yield and quantity were studied for variability in their rooting capacity. Cinnamon line SL-5 was the best with high rooting percentage and good development of primary and secondary roots. &nbsp