RANS-based Aerodynamic Shape Optimization of a Blended-Wing-Body Aircraft

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106453/1/AIAA2013-2586.pd

Lattice QCD with mixed actions

We discuss some of the implications of simulating QCD when the action used for the sea quarks is different from that used for the valence quarks. We present exploratory results for the hadron mass spectrum and pseudoscalar meson decay constants using improved staggered sea quarks and HYP-smeared overlap valence quarks. We propose a method for matching the valence quark mass to the sea quark mass and demonstrate it on UKQCD clover data in the simpler case where the sea and valence actions are the same.Comment: 15 pages, 10 figures some minor modification to text and figures. Accepted for publicatio

Modeling Boundary Layer Ingestion Using a Coupled Aeropropulsive Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143109/1/1.C034601.pd

The Hyperfine Splitting in Charmonium: Lattice Computations Using the Wilson and Clover Fermion Actions

We compute the hyperfine splitting $m_{J/\psi}-m_{\eta_c}$ on the lattice, using both the Wilson and $O(a)$-improved (clover) actions for quenched quarks. The computations are performed on a $24^3\times48$ lattice at $\beta = 6.2$, using the same set of 18 gluon configurations for both fermion actions. We find that the splitting is 1.83\err{13}{15} times larger with the clover action than with the Wilson action, demonstrating the sensitivity of the spin-splitting to the magnetic moment term which is present in the clover action. However, even with the clover action the result is less than half of the physical mass-splitting. We also compute the decay constants $f_{\eta_c}$ and $f^{-1}_{J/\psi}$, both of which are considerably larger when computed using the clover action than with the Wilson action. For example for the ratio $f^{-1}_{J/\psi}/f^{-1}_{\rho}$ we find 0.32\err{1}{2} with the Wilson action and $0.48\pm 3$ with the clover action (the physical value is 0.44(2)).Comment: LaTeX file, 8 pages and two postscript figures. Southampton Preprint: SHEP 91/92-27 Edinburgh Preprint: 92/51

Light hadron spectroscopy with O(a) improved dynamical fermions

We present the first results for the static quark potential and the light hadron spectrum using dynamical fermions at $\beta=5.2$ using an O(a) improved Wilson fermion action together with the standard Wilson plaquette action for the gauge part. Sea quark masses were chosen such that the pseudoscalar-vector mass ratio, m_PS/m_V$, varies from 0.86 to 0.67. Finite-size effects are studied by using three different volumes, 8^3\cdot 24, 12^3\cdot 24 and 16^3\cdot 24. Comparing our results to previous ones obtained using the quenched approximation, we find evidence for sea quark effects in quantities like the static quark potential and the vector-pseudoscalar hyperfine splitting.Comment: 38 pages, 14 Postscript figure, LaTe

Current Renormalisation Constants with an O(a)-improved Fermion Action

Using chiral Ward identities, we determine the renormalisation constants of bilinear quark operators for the Sheikholeslami-Wohlert action lattice at beta=6.2. The results are obtained with a high degree of accuracy. For the vector current renormalisation constant we obtain Z_V=0.817(2)(8), where the first error is statistical and the second is due to mass dependence of Z_V. This is close to the perturbative value of 0.83. For the axial current renormalisation constant we obtain Z_A = 1.045(+10 -14), significantly higher than the value obtained in perturbation theory. This is shown to reduce the difference between lattice estimates and the experimental values for the pseudoscalar meson decay constants, but a significant discrepancy remains. The ratio of pseudoscalar to scalar renormalisation constants, Z_P/Z_S, is less well determined, but seems to be slightly lower than the perturbative value.Comment: 8 pages uuencoded compressed postscript file. Article to be submitted to Phys.Rev.

Light Hadron Spectrum in Quenched Lattice QCD with Staggered Quarks

Without chiral extrapolation, we achieved a realistic nucleon to (\rho)-meson mass ratio of (m_N/m_\rho = 1.23 \pm 0.04 ({\rm statistical}) \pm 0.02 ({\rm systematic})) in our quenched lattice QCD numerical calculation with staggered quarks. The systematic error is mostly from finite-volume effect and the finite-spacing effect is negligible. The flavor symmetry breaking in the pion and (\rho) meson is no longer visible. The lattice cutoff is set at 3.63 (\pm) 0.06 GeV, the spatial lattice volume is (2.59 (\pm) 0.05 fm)(^3), and bare quarks mass as low as 4.5 MeV are used. Possible quenched chiral effects in hadron mass are discussed.Comment: 5 pages and 5 figures, use revtex

Gauge Invariant Smearing and Matrix Correlators using Wilson Fermions at beta=6.2

We present an investigation of gauge invariant smearing for Wilson fermions on a $24^3 \times 48$ lattice at $\beta = 6.2$. We demonstrate a smearing algorithm that allows a substantial improvement in the determination of the baryon spectrum obtained using propagators smeared at both source and sink, at only a small computational cost. We investigate the matrix of correlators constructed from local and smeared operators, and are able to expose excited states of both the mesons and baryons.Comment: at lattice `92. 4 pages latex + 3 postscript figures. Edinburgh preprint: 92/51

Heat loss from non-circulating domestic hot water pipes increases water consumption and energy demand

This is the final version. Available from Elsevier via the DOI in this record. Data availability: Python code for DHW-HLP model will be made available on request. The authors do not have permission to share water consumption data.Hot water use in showers is a major contributor to residential water and energy consumption, and associated costs and carbon emissions. This study aims to quantify how heat loss from non-circulating pipes contributes to water and energy consumption in residential showers. Heat loss from pipes was modelled for detached dwellings in Melbourne, Australia, using Monte Carlo analysis to quantify variability. Sensitivity analysis was conducted to identify key factors contributing to heat loss. This is the first study to quantify the variability of the impact of heat loss from pipes into increased water (and hence energy) consumption in showers. Under Melbourne conditions, we predicted that heat loss from pipes contributes approximately 2 to 10 % in average shower hot water consumption. Longer pipes, smaller diameter, longer showers and longer intervals between showers were the primary factors driving additional hot water consumption.University of Queenslan