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Solidification of a liquid in motion driven by shear and pressure gradients occurs in many natural settings and technological applications. When the liquid is electrically conducting, its solidification rates can potentially be modulated by an imposed magnetic field. The shearing motion results in viscous dissipation and the Lorentz force induced by the magnetic field causes Joule heating of the fluid, which can influence the structure of the flow, thermal fields, and thereby the solidification process. In this study, a mathematical model is developed to study the combined effects of shear and pressure gradients in the presence of a magnetic field on the solidification of a liquid between two parallel plates, with one of them being insulated and under constant motion, and the other being cooled convectively and at rest. Under the quasi‐steady assumption, closed‐form semianalytical solutions are obtained for the instantaneous location of the solid–liquid interface, Nusselt number, and dimensionless power density as a function of various characteristic parameters such as the Hartmann number, pressure gradient parameter, Brinkman number, and Biot number. Furthermore, an interesting remelt or steady‐state condition for the interfacial location is derived as arising from the competing effects of the solid side heat flux and viscous dissipation and Joule heating on the liquid side. The newly derived analytical results are shown to reduce to the various classical results in the limiting cases. A detailed systematic study is performed by the numerical solution of the semianalytical formulation, and the effects of different characteristic parameters on the solidification process are discussed. [ABSTRACT FROM AUTHOR]

This work uses an annular co-flow spray burner as a laboratory test method for evaluating one of the important jet fuel figures of merit, namely lean blowout (LBO), and investigates the coupling of physical and chemical properties affecting this phenomenon. Previous work has shown that relative trends in LBO from different fuels in a real gas turbine are well reflected in this burner setup. Representative characteristics for fuel heat of combustion, volatility, atomization, and pressure are used to produce correlations predicting the LBO for this spray burner, thus these characteristics are considered important toward the prediction of LBO in real gas turbine combustors. The results of this testing are compared to general relations for spray flames as published in prior literature; it is found that equivalence ratio at LBO is positively correlated to fuel flow rates and effective evaporation, and inversely correlated to combustion pressure, heat of combustion, and spray droplet diameter. Using simultaneous OH Planar Laser Induced Fluorescence and Mie scattering imaging of the spray and flame structure, the liquid loading in the flame region is also analyzed for surrogate jet fuels which have comparable derived cetane number (DCN) but have very different compositions. Characteristics that can affect the amount of liquid fuel entering the flame region in near-LBO conditions are discussed. The use of surrogates allows for discussion of the competing effects of volatility and reactivity of fuel components. It is found that the most stable flames occur when the interplay of fuel atomization/volatility and reactivity result in substantial penetration of fuel droplets containing components with high DCN. [ABSTRACT FROM AUTHOR]