Coelho, Victor and Keith Polk. 2016. Instrumentalists and Renaissance Culture, 1420-1600: Players of Function and Fantasy. Cambridge: Cambridge University Press.

Instrumental music permeated the soundscape of Renaissance Europe, resounding from watchtowers and ceremonial processions, echoing from the walls of castles and cathedrals, directing the steps and competing with the din of dancers’ shuffling feet, and occupying the intervals between theatrical acts and the courses of patricians’ daily banquets. Despite the ubiquity and significance of these sounds, musicologists have overlooked their presence in the landscape of Renaissance scholarship. In Instrumentalists and Renaissance Culture, 1420-1600: Players of Function and Fantasy, Victor Coelho and Keith Polk address this deficiency, bringing the work of Renaissance instrumentalists out of the historiographical margins, where it generally supports a primary focus on vocal music and notated texts. As the authors rightfully stress, this tendency is rooted in the Urtext model of compositional finitude which leaves aside the unwritten traditions of instrumental music, presenting a fixed, anachronistic work concept over the fluidity of transcriptions and arrangements (2-3, 212, 292-4). Toward this aim, Instrumentalists and Renaissance Culture joins ongoing discussions concerning extemporaneous and written composition by scholars such as Philippe Canguilhem, Rob Wegman, Julie E. Cumming, and Jessie Ann Owens, among others (Canguilhem, 2015; Wegman, 1996; Cumming, 2013; Owens, 1998; Nettl, 1974)

Development of subminiature multi-sensor hot-wire probes

Limitations on the spatial resolution of multisensor hot wire probes have precluded accurate measurements of Reynolds stresses very near solid surfaces in wind tunnels and in many practical aerodynamic flows. The fabrication, calibration and qualification testing of very small single horizontal and X-array hot-wire probes which are intended to be used near solid boundaries in turbulent flows where length scales are particularly small, is described. Details of the sensor fabrication procedure are reported, along with information needed to successfully operate the probes. As compared with conventional probes, manufacture of the subminiature probes is more complex, requiring special equipment and careful handling. The subminiature probes tested were more fragile and shorter lived than conventional probes; they obeyed the same calibration laws but with slightly larger experimental uncertainty. In spite of these disadvantages, measurements of mean statistical quantities and spectra demonstrate the ability of the subminiature sensors to provide the measurements in the near wall region of turbulent boundary layers that are more accurate than conventional sized probes

A Study of Dean Vortex Development and Structure in a Curved Rectangular Channel with Aspect Ratio of 40 at Dean Numbers up to 430

Flow in a curved channel with mild curvature, an aspect ratio of 40 to 1, and an inner to outer radius ratio of 0.979 is studied at Dean numbers De ranging from 35 to 430. For positions from the start of curvature ranging from 85 to 145 degrees, the sequence of transition events begins with curved channel Poiseuille flow at De less than 40-64. As the Dean number increases, observations show initial development of Dean vortex pairs, followed by symmetric vortex pairs which, when viewed in spanwise/radial planes, cover the entire channel height (De=90-100). At De from 40 to 125-130, the vortex pairs often develop intermittent waviness in the form of vortex undulations. Splitting and merging of vortex pairs is also observed over the same experimental conditions as well as at higher De. When Dean numbers range from 130 to 185-200, the undulating wavy mode is replaced by a twisting mode with higher amplitudes of oscillation and shorter wavelengths. The twisting wavy mode results in the development of regions where turbulence intensity is locally augmented at Dean numbers from 150 to 185-200, principally in the upwash regions between the two individual vortices which make up each vortex pair. These turbulent regions eventually increase in intensity and spatial extent as the Dean number increases further, until individual regions merge together so that the entire cross section of the channel contains chaotic turbulent motions. When Dean numbers then reach 400-435, spectra of velocity fluctuations then evidence fully turbulent flow

Dean Flow Dynamics in Low-Aspect Ratio Spiral Microchannels

A wide range of microfluidic cell-sorting devices has emerged in recent years, based on both passive and active methods of separation. Curvilinear channel geometries are often used in these systems due to presence of secondary flows, which can provide high throughput and sorting efficiency. Most of these devices are designed on the assumption of two counter rotating Dean vortices present in the curved rectangular channels and existing in the state of steady rotation and amplitude. In this work, we investigate these secondary flows in low aspect ratio spiral rectangular microchannels and define their development with respect to the channel aspect ratio and Dean number. This work is the first to experimentally and numerically investigate Dean flows in microchannels for Re > 100, and show presence of secondary Dean vortices beyond a critical Dean number. We further demonstrate the impact of these multiple vortices on particle and cell focusing. Ultimately, this work offers new insights into secondary flow instabilities for low-aspect ratio, spiral microchannels, with improved flow models for design of more precise and efficient microfluidic devices for applications such as cell sorting and micromixing

Aerodynamic Losses in Turbines with and without Film Cooling, as Influenced by Mainstream Turbulence, Surface Roughness, Airfoil Shape, and Mach Number

The influences of a variety of different physical phenomena are described as they affect the aerodynamic performance of turbine airfoils in compressible, high-speed flows with either subsonic or transonic Mach number distributions. The presented experimental and numerically predicted results are from a series of investigations which have taken place over the past 32 years. Considered are (i) symmetric airfoils with no film cooling, (ii) symmetric airfoils with film cooling, (iii) cambered vanes with no film cooling, and (iv) cambered vanes with film cooling. When no film cooling is employed on the symmetric airfoils and cambered vanes, experimentally measured and numerically predicted variations of freestream turbulence intensity, surface roughness, exit Mach number, and airfoil camber are considered as they influence local and integrated total pressure losses, deficits of local kinetic energy, Mach number deficits, area-averaged loss coefficients, mass-averaged total pressure loss coefficients, omega loss coefficients, second law loss parameters, and distributions of integrated aerodynamic loss. Similar quantities are measured, and similar parameters are considered when film-cooling is employed on airfoil suction surfaces, along with film cooling density ratio, blowing ratio, Mach number ratio, hole orientation, hole shape, and number of rows of holes

Coelho, Victor and Keith Polk. 2016. Instrumentalists and Renaissance Culture, 1420-1600: Players of Function and Fantasy. Cambridge: Cambridge University Press.

Instrumental music permeated the soundscape of Renaissance Europe, resounding from watchtowers and ceremonial processions, echoing from the walls of castles and cathedrals, directing the steps and competing with the din of dancers’ shuffling feet, and occupying the intervals between theatrical acts and the courses of patricians’ daily banquets. Despite the ubiquity and significance of these sounds, musicologists have overlooked their presence in the landscape of Renaissance scholarship

Resume of Phillip Meredith Ligrani, 1984

Naval Postgraduate School Faculty Resum

Secondary flows and extra heat transfer enhancement of ribbed surfaces with jet impingement

Previous experiments recognize that substantial heat transfer augmentation is achieved by adding ribbed turbulators after jet impingement with cross flow present. To address fundamental working mechanisms, conjugate CFD simulations are employed for ribs, jet impingement, and their combinations. Flow characteristics and drawbacks for the individual and combined enhancement techniques are highlighted. New analysis on the coupled design arrangement reveals that the counter-rotating vortices generated by the jet flow can energize inter-rib recirculating vortices and promote span-wise convection. With an optimal design combination arrangement, extra heat transfer benefit is achieved beyond that associated with simple superposition of rib and jet impingement techniques