38 research outputs found
TranAir: A full-potential, solution-adaptive, rectangular grid code for predicting subsonic, transonic, and supersonic flows about arbitrary configurations. User's manual
The TranAir computer program calculates transonic flow about arbitrary configurations at subsonic, transonic, and supersonic freestream Mach numbers. TranAir solves the nonlinear full potential equations subject to a variety of boundary conditions modeling wakes, inlets, exhausts, porous walls, and impermeable surfaces. Regions with different total temperature and pressure can be represented. The user's manual describes how to run the TranAir program and its graphical support programs
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Performing television history
An expanded conception of performance study can disturb current theoretical and historical assumptions about televisionâs medial identity. The article considers how to write histories of the dominant forms and assumptions about performance in British and American television drama, and analyses how acting is situated in relation to the multiple meaning-making components of television. A longitudinal, wide-ranging analysis is briefly sketched to show that the concept of performance, from acting to the display of televisionâs mediating capability, can extend to the analysis of how the television medium âperformedâ its own identity to shape its distinctiveness in specific historical circumstances
Speciation, Luminescence, and Alkaline Fluorescence Quenching of 4-(2-methylbutyl)aminodipicolinic acid (H2MEBADPA)
4-(2-Methylbutyl)aminodipicolinic acid (H2MEBADPA) has been synthesized and fully characterized in terms of aqueous phase protonation constants (pKa\u27s) and photophysical measurements. The pKa\u27s were determined by spectrophotometric titrations, utilizing a fully sealed titration system. Photophysical measurements consisted of room temperature fluorescence and frozen solution phosphorescence as well as quantum yield determinations at various pH, which showed that only fully deprotonated MEBADPA2â is appreciably emissive. The fluorescence of MEBADPA2â has been determined to be quenched by hydroxide and methoxide anions, most likely through base-catalyzed excited-state tautomerism or proton transfer. This quenching phenomenon has been quantitatively explored through steady-state and time-resolved fluorescence measurements. Utilizing the determined pKas and quenching constants, the fluorescent intensity of MEBADPA2â has been successfully modeled as a function of pH
âNew and important careersâ: how women excelled at the BBC, 1923â1939
From its beginnings in 1923, the BBC employed a sizeable female workforce. The majority were in support roles as typists, secretaries and clerks but, during the 1920s and 1930s, a significant number held important posts. As a modern industry, the BBC took a largely progressive approach towards the âcareer womenâ on its staff, many of whom were in jobs that were developed specifically for the new medium of broadcasting. Women worked as drama producers, advertising representatives and Childrenâs Hour Organisers. They were talent spotters, press officers and documentary makers. Three women attained Director status while others held significant administrative positions. This article considers in what ways it was the modernity and novelty of broadcasting, combined with changing employment possibilities and attitudes towards women evident after the First World War, that combined to create the conditions in which they could excel
Observations Regarding Algorithms Required for Robust CFD Codes
Over the last three decades Computational Fluid Dynamics (CFD) has gradually joined the
wind tunnel and flight test as a primary flow analysis tool for aerodynamic designers. CFD
has had its most favorable impact on the aerodynamic design of the high-speed cruise
configuration of a transport. This success has raised expectations among aerodynamicists
that the applicability of CFD can be extended to the full flight envelope. However, the
complex nature of the flows and geometries involved places substantially increased demands
on the solution methodology and resources required. Currently most simulations involve
Reynolds-Averaged Navier-Stokes (RANS) codes although Large Eddy Simulation (LES) and
Detached Eddy Suimulation (DES) codes are occasionally used for component analysis or
theoretical studies. Despite simplified underlying assumptions, current RANS turbulence
models have been spectacularly successful for analyzing attached, transonic flows. Whether
or not these same models are applicable to complex flows with smooth surface separation is
an open question. A prerequisite for answering this question is absolute confidence that
the CFD codes employed reliably solve the continuous equations involved. Too often,
failure to agree with experiment is mistakenly ascribed to the turbulence model rather
than inadequate numerics. Grid convergence in three dimensions is rarely achieved. Even
residual convergence on a given grid is often inadequate. This paper discusses issues
involved in residual and especially grid convergence