Aeroservoelastic modeling and applications using minimum-state approximations of the unsteady aerodynamics

Various control analysis, design, and simulation techniques for aeroelastic applications require the equations of motion to be cast in a linear time-invariant state-space form. Unsteady aerodynamics forces have to be approximated as rational functions of the Laplace variable in order to put them in this framework. For the minimum-state method, the number of denominator roots in the rational approximation. Results are shown of applying various approximation enhancements (including optimization, frequency dependent weighting of the tabular data, and constraint selection) with the minimum-state formulation to the active flexible wing wind-tunnel model. The results demonstrate that good models can be developed which have an order of magnitude fewer augmenting aerodynamic equations more than traditional approaches. This reduction facilitates the design of lower order control systems, analysis of control system performance, and near real-time simulation of aeroservoelastic phenomena

An "intermountain miracle"?

Idaho ; Utah ; Regional economics ; Economic conditions - West (U.S.)

Western manufacturing: bucking the national trend?

Federal Reserve District, 12th ; West (U.S.)

California's recent performance

California ; Federal Reserve District, 12th

NAFTA and the western economy

North American Free Trade Agreement ; International trade ; California ; Arizona ; Mexico ; West (U.S.)

Why do regional economies differ?

Washington (State) ; Oregon ; Northwest, Pacific ; Regional economics ; Natural resources - West ; Federal Reserve District, 12th

Sensors for ceramic components in advanced propulsion systems: Summary of literature survey and concept analysis, task 3 report

The results of a literature survey and concept analysis related to sensing techniques for measuring of surface temperature, strain, and heat flux for (non-specific) ceramic materials exposed to elevated temperatures (to 2200 K) are summarized. Concepts capable of functioning in a gas turbine hot section environment are favored but others are reviewed also. Recommendation are made for sensor development in each of the three areas

Studies of nucleotide sequences in TMV-RNA. II - The action of spleen diesterase

Spleen diesterase action on polynucleotide and ribonucleic acid infectivit