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)
This paper describes a new fast hybrid adaptive grid generation technique for arbitrary twodimensional 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 practice of statistics in the pharmaceutical industry has changed markedly over the last 25 years. This paper examines the evolution of clinical trial statistics in relationship to advances in statistical methodology and computational power as well as the changing regulatory environment. The current role of the biopharmaceutical statistician is assessed(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)
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 illustrates aspects of data monitoring of clinical trials in the pharmaceutical industry. Formal interim analyses are performed at least in part to address the question of whether the trial should proceed or whether there should be an early termination of the trial. For formal interim analyses, frequently independent data and safety monitoring(More)
The results from a steady, viscous flow simulation of the main flowpath of a modern jet engine transonic highpressure 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)
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)