NASA Scientific and Technical Aerospace Reports - The University ...

elated to the performance of a component such as a turbopump, valve or a flow control element, the associated pressure
fluctuations as they propagate through the system have the potential to amplify and resonate with natural modes of the
structural elements and components of the system. In this paper, the authors have developed an innovative multi-level
approach that involves analysis at the component and systems level. The primary source of the unsteadiness is modeled with
a high-fidelity hybrid RANS/LES based CFD methodology that has been previously used to study instabilities in feed systems.
This high fidelity approach is used to quantify the instability and understand the physics associated with the instability. System
response to the driving instability is determined through a transfer matrix approach wherein the incoming and outgoing
pressure and velocity fluctuations are related through a transfer (or transmission) matrix. The coefficients of the transfer matrix
for each component (i.e. valve, pipe, orifice etc.) are individually derived from the flow physics associated with the
component. A demonstration case representing a test loop/test facility comprised of a network of elements is constructed with
the transfer matrix approach and the amplification of modes analyzed as the instability propagates through the test loop.
Author
Computational Fluid Dynamics; Stability; Structural Vibration; Damage; Feed Systems; Pressure Oscillations; Rocket
Engines
20100017152 Arizona Univ., Tucson, AZ, USA; Arizona Univ., Tucson, AZ, USA
Particle and Blood Cell Dynamics in Oscillatory Flows. Final Report
Restrepo, Juan M.; September 2008; 10 pp.; In English
Report No.(s): DE2009-953697; No Copyright; Avail.: National Technical Information Service (NTIS)
Our aim has been to uncover fundamental aspects of the suspension and dislodgement of particles in wall-bounded
oscillatory flows, in flows characterized by Reynolds numbers en- compassing the situation found in rivers and near shores
(and perhaps in some industrial processes). Our research tools are computational and our coverage of parameter space fairly
broad. Computational means circumvent many complications that make the measurement of the dynamics of particles in a
laboratory setting an impractical task, especially on the broad range of parameter space we plan to report upon. The impact
of this work on the geophysical problem of sedimentation is boosted considerably by the fact that the proposed calculations
can be considered ab-initio, in the sense that little to no modeling is done in generating dynamics of the particles and of the
moving fluid: we use a three-dimensional Navier Stokes solver along with straightforward boundry conditions. Hence, to the
extent that Navier Stokes is a model for an ideal incompressible isotropic Newtonian fluid, the calculations yield benchmark
values for such things as the drag, buoyancy, and lift of particles, in a highly controlled environment. Our approach will be
to make measurements of the lift, drag, and buoyancy of particles, by considering progressively more complex physical
configurations and physics.
NTIS
Boundary Conditions; Oscillations; Reynolds Number; Simulation
20100017173 Rhode Island Univ., Kingston, RI, USA
Towards a National Marine Pollution Policy. Proceedings from a Workshop on Marine Pollution Policy. Held in
Galilee, Rhode Island on June 25-27, 1980
January 1980; 88 pp.; In English; Towards a National Marine Pollution Policy. A Workshop on Marine Pollution Policy., 25
- 27 Jun. 1980, Galilee, Rhode Island, USA
Report No.(s): PB2010-104026; No Copyright; Avail.: CASI: A05, Hardcopy
The general purpose of this workshop was (1) to review and evaluate the effectiveness of approaches we take in defining
important marine pollution problems and in organizing research and monitoring activities in response to those problems, and
(2) to recommend new strategies and approaches, where needed, in order to improve the usefulness and timeliness of
information and to better address marine pollution problems in the 1980s. Workshop discussions were focused around three
topic areas: Marine Waste Disposal; Outer Continental Shelf Oil and Gas Development; and Hazardous Material Spill Damage
Assessment. State of the art papers were presented on each topic area.
NTIS
Conferences; Policies; Water Pollution
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