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The narratives of the reign of the last Amorian emperor, Michael III (r. 842–867), and the government of his uncle, Caesar Bardas (r. 856–866), were mostly authored by hostile Macedonian chroniclers living a century or so following the events they describe. This fact poses considerable difficulties for the historiographical assessment of this period. Recently brought to scholarly attention, a Shīʿī Arabic account has been presented in previous scholarship as a counter-narrative to Byzantine historians' portrayal of the period of interest. The present study sets out to, first, re-appraise, in the light of fresh historical testimonies, the extent of Byzantine records' affinities with this "ignored Arabic account" and second, to gauge whether this Arabic evidence can be an aid in filling the historiographical lacuna created by the Byzantine chroniclers' and hagiographers' one-sided depiction of the late Amorian period. The latter aim will be pursued via analysis of the rival representations of a traumatic event which happened during Bardas's rule, namely the earthquake of Constantinople. [ABSTRACT FROM AUTHOR]

Imperial and aristocratic Byzantine women had a wide variety of roles with a spectrum of importance. One possible way to enrich our information about Byzantine royal women is to consult the historical and cultural heritage of Byzantium's adjacent territories. The primary aim of this article is thus to trace Byzantine women in the Arabic Shīʿī literature, as exemplified by the underutilised autobiography of a hitherto unidentified Roman princess named Malīka. Probably because Malīka's autobiography, along with its hagiographic and miraculous elements, is found in a source from the Shīʿī Ḥadīth tradition, the account's potential historical value has escaped the notice of previous Byzantinists. Despite its hagiographic character, Malīka's story has a historical core. Through an intertextual study between the Arabic and Byzantine historical texts, the present study seeks to shed light on the identification of Malīka and her paternal ancestry. [ABSTRACT FROM AUTHOR]

Recently, a new family of subgrid-scale (SGS) models, termed as gradient-based models, has been introduced to calculate the SGS stresses in large eddy simulation (LES). In the present work, the modulated gradient model (MGM) was implemented in the OpenFOAM package, and the pimpleFoam solver was improved to be adopted with non-eddy viscosity models. The MGM is a new, nonlinear model that uses the local equilibrium hypothesis to assess the SGS kinetic energy and the velocity gradient tensor to calculate the relative weight of the different components of the SGS stress tensor. To evaluate the accuracy of the MGM along with the modified pimpleFoam solver, a turbulent channel flow was simulated at the three different frictional Reynolds numbers of 180, 395 and 590. Furthermore, the results were compared with direct numerical simulation data, as well as the numerical results obtained by the established SGS models such as the dynamic Smagorinsky model (DSM). A suitable accuracy for the first- and second-order turbulence parameters was reported. Moreover, it was demonstrated that MGM is computationally efficient compared to the DSM in treating channel flow. [ABSTRACT FROM AUTHOR]

In the current study, we performed a DSMC investigation to study the nonequilibrium effects on monatomic and diatomic rarefied flows in micro/nano lid-driven cavity. Our DSMC solver is parallel and benefits from a variable time step algorithm. The results of our simulation showed that growing rarefaction effects increase the maximum temperature of the cavity flow. As the inter-molecular rate of collision diminishes in the nonequilibrium regime, molecules manage to conserve their obtained energy from diffused surfaces; consequently, the flow temperature increases. We also investigate the nonequilibrium effects on the shear stress profile in the micro/nano cavity. Although increasing the Knudsen number decreases flow shear stress, the nondimensional shear stress, which shows the molecular potential for performing collision in the rarefied flow, increases. [ABSTRACT FROM AUTHOR]

In this study, transient 2D/axisymmetric simulations of cavitating flows are performed using a modified 'Volume-of-Fluid' (VOF) technique. Simulation of the cavitation is based on a homogenous equilibrium flow model. To predict the shape of the cavity, the Navier-Stokes equations in addition to an advection equation for the liquid volume fraction are solved. Mass transfer between the phases is treated as a sink term in the VOF equation. The numerical method is used for different geometries in a wide range of cavitation numbers. Computed shapes of cavities were found to be in good agreement with those of the reported experiments. The simulation results also compared well with those obtained from analytical relations. [ABSTRACT FROM AUTHOR]

This paper evaluates the suitability of a newly developed hybrid “Langmuir–Maxwell” and “Langmuir–Smoluchowski” slip/jump boundary conditions in the Navier–Stokes–Fourier equations for nano-/micro-backward-facing step geometry flow which experiences separation and reattachment. Additionally, this paper investigates the effect of different parameters such as step pressure ratio, inflow temperature, and wall temperature on the separation zone in the nano-/micro-step geometry. We chose nitrogen as the working gas and use two direct simulation Monte Carlo (DSMC) solvers to assess the accuracy of the computational fluid dynamics (CFD) solutions. DSMC results showed that the increase of the inlet temperatures extends the length of the separation zone and raises the mass flow rate. The change of pressure ratio does not affect the separation length while the increase of the step wall temperature decreases the length of this zone for both CFD and DSMC results. Compared to the DSMC results, the hybrid slip/jump boundary conditions predict better surface pressure, surface gas temperature, and slip velocity in the separation zone than the standard Maxwell/Smoluchowski boundary conditions. [ABSTRACT FROM AUTHOR]