Roger L. Davis

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Researchers have recently used the new programmable capabilities of the Graphics Processing Unit (GPU) to increase the performance of scientific codes. We investigate the use of a cluster of GPUs for large-scale CFD problems and show order-of-magnitude increases in performance and performance-to-price ratio. We implement two separate compressible flow(More)
A new high-performance general-purpose graphics processing unit (GPGPU) computational fluid dynamics (CFD) library is introduced for use with structured-grid CFD algorithms. A novel set of parallel tridiagonal matrix solvers, implemented in CUDA, is included for use with structured-grid CFD algorithms. The solver library supports both scalar and(More)
Nomenclature E = total energy g = acceleration due to gravity H = total enthalpy h = static enthalpy I = rothalpy k = turbulent kinetic energy p = pressure Pr = Prandtl number Pr t = turbulent Prandtl number R = radius from specified axis of rotation S ij = mean strain-rate tensor u = axial velocity component u ˆ = internal energy v = tangential velocity(More)
SUMMARY This paper describes a new fast hybrid adaptive grid generation technique for arbitrary two-dimensional domains. This technique is based on a Cartesian background grid with square elements and quadtree decomposition. A new algorithm is introduced for the distribution of boundary points based on the curvature of the domain boundaries. The quadtree(More)
The results from two numerical simulations of the unsteady flow in a 1-1/2 stage axial-flow turbine are presented and compared with experimental data to show both the effect of blade count on the solution accuracy and the time-averaged and unsteady flow physics present. The TFLO three-dimensional, multi-block, massively parallel turbomachinery flow solution(More)
  • R L Davis
  • 1986
Raising and lowering the oxygen content in the fluid bathing the skin of the leech modified the frequency of the heartbeat. In raised concentrations of oxygen, the period between bursts of impulses in the heart excitor motoneurones (HE cells) was reduced. Conversely, with lowered oxygen concentrations bathing the skin, the heart rate was slowed, with longer(More)
1. The voltage-dependent properties of rectifying and non-rectifying electrical synapses formed between identified leech neurones were quantified during their regeneration in vitro. 2. Junctional conductance increased with time in culture. This was evaluated by making comparisons between cell pairs maintained in vitro for differing amounts of time, as well(More)
The results from a steady, viscous flow simulation of the main flowpath of a modern jet engine transonic high-pressure turbine, transition duct, and first vane of the low-pressure turbine, coupled with the secondary-air system under the high-pressure turbine, is presented. The secondary-air system configuration includes the lower cavity near the centerline,(More)
A new adaptive technique for the simulation of unsteady incompressible flows is presented. The initial mesh is generated based on a Cartesian grid with spatial decomposition and a simple optimization step to define the boundaries of the domain. This technique is fast and produces a quad-dominant mesh, while preserving the quality of the elements. Adaptive(More)
This paper describes the design, implementation and validation of a method to couple multiprocessor solvers whose solution domains share a common surface. Using Message Passing Interface (MPI) constructs, parallel communication pathways are established between various simulation codes. These pathways allow applications to exchange data, synchronize time(More)