E. A. Bogucz

The turbulent near wake at a sharp trailing edge

The problem of a turbulent boundary layer that evolves into a wake flow at the sharp trailing edge of a thin flat plate is considered; the formal structure of the near-wake flow is investigated using matched expansions in the limit of infinite Reynolds number. The symmetric turbulent near wake is shown to develop a two-layer structure which is independent of turbulence model. The general asymptotic analysis shows that a thin layer at the wake centreline grows linearly with distance from the trailing edge while the centreline velocity varies logarithmically in a manner that is supported strongly by experimental measurements. The relatively thick outer layer of the near-wake flow is undisturbed by the evolution of the inner layer to leading order. An additional region near the trailing edge is required to resolve a nonuniformity in transverse velocity. The general asymptotic results are used to guide the development of a zonal turbulence model the near wake in the form of a simple eddy viscosity formula. Analytic profiles for velocity and Reynolds stress are obtained for the near-wake region; these profiles are shown to provide accurate representations of available near-wake experimental data.

InfoMall: A Scalable Organisation for the Development of High-Performance Computing and Communications - Software and Systems

InfoMall is a programme lead by the Northeast Parallel Architectures Center (NPAC) featuring a partnership of over twenty-five organisations and a plan for accelerating development of the High Performance Computing and Communications (HPCC) software and systems industry. HPCC (or HPCN as it is known in Europe) is a critical technology which will have unprecedented impact on industry, education, society, and defense. Acceptance of HPCC by these real world sectors is held up by the extremely hard problem of HPCC software development. InfoMall employs a novel technology development strategy involving closely linked programmes in technology execution and certification, software development, marketing, education and training, economic development and small business support. InfoMall has excellent HPCC and other facility infrastructure. InfoMall partners have unrivaled expertise in all the areas critical to rapid development of the HPCC software industry. The process is constructed and explained by analogy to the full-service set of stores found in a shopping mall. InfoMall is a concept which can create 15,000 jobs in New York State alone, and be scaled in future years to create an order of magnitude more jobs nationally.

Evacuation of a Residual Oil Pipeline by Inert Gas Displacement

This paper describes an analysis developed to model the inert gas displacement process for evacuating a high-pour-point oil from a long pipeline. The governing equations were derived from the basic conservation equations for mass, momentum, and energy. The resultant computer program accounts for such effects as pipeline elevation changes, laminar and turbulent oil flow, temperature-dependent oil viscosity, and heat loss from the oil to the ground. Results of computations for an 84-mile (135-km) residual oil pipeline operated by the Pennsylvania Power and Light Co. are presented and compared with pressure measurements obtained during a trial purge of the system. Calculations show that the minimum N/sub 2/ volume required for a successful pipeline evacuation increases considerably with increased delay time. In addition, theoretical results indicate that for this case, the pipeline purge operation must begin within 20 hours of a shutdown to avoid evacuation difficulties.

CFD algorithms in high performance fortran

We evaluate the High-Performance Fortran (HPF) language for expressing and implementing algorithms for Computational Fluid Dynamics (CFD) applications on high performance computing systems. In particular we discuss: implicit methods such as the ADI algorithm , full-matrix methods such as the panel method, and sparse matrix methods such as conjugate gradient. We focus on regular meshes, since these can be eeciently represented by the existing HPF deenition. other educational and discussion material related to applications in HPF.

Implementation of a 3D mixing layer code on parallel computers

This paper summarizes our progress and experience in the development of a Computational-Fluid-Dynamics code on parallel computers to simulate three-dimensional spatially-developing mixing layers. In this initial study, the three-dimensional time-dependent Euler equations are solved using a finite-volume explicit time-marching algorithm. The code was first programmed in Fortran 77 for sequential computers. The code was then converted for use on parallel computers using the conventional message-passing technique, while we have not been able to compile the code with the present version of HPF compilers.

Research and educational initiatives at the Syracuse University Center for Hypersonics

The Department of Mechanical, Aerospace, and Manufacturing Engineering and the Northeast Parallel Architectures Center of Syracuse University have been funded by NASA to establish a program to educate young engineers in the hypersonic disciplines. This goal is being achieved through a comprehensive five-year program that includes elements of undergraduate instruction, advanced graduate coursework, undergraduate research, and leading-edge hypersonics research. The research foci of the Syracuse Center for Hypersonics are three-fold; high-temperature composite materials, measurements in turbulent hypersonic flows, and the application of high-performance computing to hypersonic fluid dynamics.