Conformal anomaly from gauge fields without gauge fixing

We show how the Weyl anomaly generated by gauge fields, can be computed from manifestly gauge invariant and diffeomorphism invariant exact renormalization group equations, without having to fix the gauge at any stage. Regularisation is provided by covariant higher derivatives and by embedding the Maxwell field into a spontaneously broken $U(1|1)$ supergauge theory. We first provide a realisation that leaves behind two versions of the original $U(1)$ gauge field, and then construct a manifestly $U(1|1)$ supergauge invariant flow equation which leaves behind only the original Maxwell field in the spontaneously broken regime.Comment: 24 page

Navier-Stokes turbine heat transfer predictions using two-equation turbulence

Navier-Stokes calculations were carried out in order to predict the heat transfer rates on turbine blades. The calculations were performed using TRAF2D which is a two-dimensional, explicit, finite volume mass-averaged Navier-Stokes solver. Turbulence was modeled using q-omega and k-epsilon two-equation models and the Baldwin-Lomax algebraic model. The model equations along with the flow equations were solved explicitly on a non-periodic C grid. Implicit residual smoothing (IRS) or a combination of multigrid technique and IRS was applied to enhance convergence rates. Calculations were performed to predict the Stanton number distributions on the first stage vane and blade row as well as the second stage vane row of the Rocketdyne Space Shuttle Main Engine (SSME) high pressure fuel turbine. The comparison with the experimental results, although generally favorable, serves to highlight the weaknesses of the turbulence models and the possible areas of improving these models for use in turbomachinery heat transfer calculations

Multigrid calculation of three-dimensional viscous cascade flows

A 3-D code for viscous cascade flow prediction was developed. The space discretization uses a cell-centered scheme with eigenvalue scaling to weigh the artificial dissipation terms. Computational efficiency of a four stage Runge-Kutta scheme is enhanced by using variable coefficients, implicit residual smoothing, and a full multigrid method. The Baldwin-Lomax eddy viscosity model is used for turbulence closure. A zonal, nonperiodic grid is used to minimize mesh distortion in and downstream of the throat region. Applications are presented for an annular vane with and without end wall contouring, and for a large scale linear cascade. The calculation is validated by comparing with experiments and by studying grid dependency

Navier-Stokes analysis of transonic cascade flow

A new kind of C-type grid is proposed, this grid is non-periodic on the wake and allows minimum skewness for cascades with high turning and large camber. Reynolds-averaged Navier-Stokes equations are solved on this type of grid using a finite volume discretization and a full multigrid method which uses Runge-Kutta stepping as the driving scheme. The Baldwin-Lomax eddy-viscosity model is used for turbulence closure. A detailed numerical study is proposed for a highly loaded transonic blade. A grid independence analysis is presented in terms of pressure distribution, exit flow angles, and loss coefficient. Comparison with experiments clearly demonstrates the capability of the proposed procedure

Ising Spin Glasses on Wheatstone-Bridge Hierarchical Lattices

Nearest-neighbor-interaction Ising spin glasses are studied on three different hierarchical lattices, all of them belonging to the Wheatstone-Bridge family. It is shown that the spin-glass lower critical dimension in these lattices should be greater than 2.32. Finite-temperature spin-glass phases are found for a lattice of fractal dimension $D \approx 3.58$ (whose unit cell is obtained from a simple construction of a part of the cubic lattice), as well as for a lattice of fractal dimension close to five.Comment: Accepted for publication in Physics Letters

Transonic cascade flow calculations using non-periodic C-type grids

A new kind of C-type grid is proposed for turbomachinery flow calculations. This grid is nonperiodic on the wake and results in minimum skewness for cascades with high turning and large camber. Euler and Reynolds averaged Navier-Stokes equations are discretized on this type of grid using a finite volume approach. The Baldwin-Lomax eddy-viscosity model is used for turbulence closure. Jameson's explicit Runge-Kutta scheme is adopted for the integration in time, and computational efficiency is achieved through accelerating strategies such as multigriding and residual smoothing. A detailed numerical study was performed for a turbine rotor and for a vane. A grid dependence analysis is presented and the effect of artificial dissipation is also investigated. Comparison of calculations with experiments clearly demonstrates the advantage of the proposed grid

Robert A. Arnone

Robert Arnone\u27s expertise is in the coupling biological optical and physical processes using ocean color satellite combined with ocean models. He has developed bio-optical algorithms from satellites and applied to ecological forecasting models using data assimilation from ship and gliders. He has developed new at sea optical instrumentation for measuring optical properties of ocean waters. Robert Arnone leads the National Ocean calibration and validation efforts for the Joint Polar Satellite System for NOAA, NASA, and Navy the NPP satellite ocean calibration and validation team with NOAA and university for SST and ocean color. He managed NRL’s Hyperspectral satellite Hyperspectral Imaging of the Coastal Environment (HICO) which was successfully launched to the International Space Station (Aug 2009). He serves on science teams for NASA, NOAA, EPA and Navy for developing future satellite systems and for establishing policy for ocean and coastal research (MODIS, SeaWIFS, VIIRS, GEOCAPE ,HICO). He has over 120 scientific publications and \u3e250 presentations in the areas of physical and bio-optical ocean processes. He has lead over 15 major national and international scientific oceanographic expeditions in the world oceans including Arabian Sea, Mediterranean, Japan East Sea, Iceland Greenland, and Gulf Stream . He has received awards for honors for “science to operations” transitions and NRL publication awards 1998 , 2002, 2008. He has received 2 Navy patents and NASA honors for astronaut training programs. He has received awards for Navy Meritorious Civilian Service Award ; US Dept of Navy - honors, and; NASA - honors for Shuttle Astronaut Training program, Navy Royalty Transition award. Her has served on graduate student committees at USM, RSMAS, and University of Southern Alabama. Robert Arnone retired from the Navy Research Laboratory as head of the Ocean Science Branch

Robert A. Arnone

Robert Arnone\u27s expertise is in the coupling biological optical and physical processes using ocean color satellite combined with ocean models. He has developed bio-optical algorithms from satellites and applied to ecological forecasting models using data assimilation from ship and gliders. He has developed new at sea optical instrumentation for measuring optical properties of ocean waters. Robert Arnone leads the National Ocean calibration and validation efforts for the Joint Polar Satellite System for NOAA, NASA, and Navy the NPP satellite ocean calibration and validation team with NOAA and university for SST and ocean color. He managed NRL’s Hyperspectral satellite Hyperspectral Imaging of the Coastal Environment (HICO) which was successfully launched to the International Space Station (Aug 2009). He serves on science teams for NASA, NOAA, EPA and Navy for developing future satellite systems and for establishing policy for ocean and coastal research (MODIS, SeaWIFS, VIIRS, GEOCAPE ,HICO). He has over 120 scientific publications and \u3e250 presentations in the areas of physical and bio-optical ocean processes. He has lead over 15 major national and international scientific oceanographic expeditions in the world oceans including Arabian Sea, Mediterranean, Japan East Sea, Iceland Greenland, and Gulf Stream . He has received awards for honors for “science to operations” transitions and NRL publication awards 1998 , 2002, 2008. He has received 2 Navy patents and NASA honors for astronaut training programs. He has received awards for Navy Meritorious Civilian Service Award ; US Dept of Navy - honors, and; NASA - honors for Shuttle Astronaut Training program, Navy Royalty Transition award. Her has served on graduate student committees at USM, RSMAS, and University of Southern Alabama. Robert Arnone retired from the Navy Research Laboratory as head of the Ocean Science Branch

Viscous analysis of three-dimensional rotor flows using a multigrid method

A three-dimensional code for rotating blade-row flow analysis was developed. The space discretization uses a cell-centered scheme with eigenvalues scaling for the artificial dissipation. The computational efficiency of a four-stage Runge-Kutta scheme is enhanced by using variable coefficients, implicit residual smoothing, and a full-multigrid method. An application is presented for the NASA rotor 67 transonic fan. Due to the blade stagger and twist, a zonal, non-periodic H-type grid is used to minimize the mesh skewness. The calculation is validated by comparing it with experiments in the range from the maximum flow rate to a near-stall condition. A detailed study of the flow structure near peak efficiency and near stall is presented by means of pressure distribution and particle traces inside boundary layers