Numerical simulations of supersonic flow through oscillating cascade sections

A finite difference code was developed for modeling inviscid, unsteady supersonic flow by solution of the compressible Euler equations. The code uses a deforming grid technique to capture the motion of the airfoils and can model oscillating cascades with any arbitrary interblade phase angle. A flat plate cascade is analyzed, and results are compared with results from a small perturbation theory. The results show very good agreement for both the unsteady pressure distributions and the integrated force predictions. The reason for using the numerical Euler code over a small perturbation theory is the ability to model real airfoils that have thickness and camber. Sample predictions are presented for a cascade of loaded airfoils and show appreciable differences in the unsteady surface pressure distributions when compared with the flat plate results

Numerical analysis of supersonic flow through oscillating cascade sections by using a deforming grid

A finite difference code was developed for modeling inviscid, unsteady supersonic flow by solution of the compressible Euler equations. The code uses a deforming grid technique to capture the motion of the airfoils and can model oscillating cascades with any arbitrary interblade phase angle. A flat plate cascade is analyzed, and results are compared with results from a small-perturbation theory. The results show very good agreement for both the unsteady pressure distributions and the integrated force predictions. The reason for using the numerical Euler code over a small-perturbation theory is the ability to model real airfoils that have thickness and camber. Sample predictions are presented for a section of the rotor on a supersonic throughflow compressor designed at NASA Lewis Research Center. Preliminary results indicate that two-dimensional, flat plate analysis predicts conservative flutter boundaries

Euler flow predictions for an oscillating cascade using a high resolution wave-split scheme

A compressible flow code that can predict the nonlinear unsteady aerodynamics associated with transonic flows over oscillating cascades is developed and validated. The code solves the two dimensional, unsteady Euler equations using a time-marching, flux-difference splitting scheme. The unsteady pressures and forces can be determined for arbitrary input motions, although only harmonic pitching and plunging motions are addressed. The code solves the flow equations on a H-grid which is allowed to deform with the airfoil motion. Predictions are presented for both flat plate cascades and loaded airfoil cascades. Results are compared to flat plate theory and experimental data. Predictions are also presented for several oscillating cascades with strong normal shocks where the pitching amplitudes, cascade geometry and interblade phase angles are varied to investigate nonlinear behavior

A program to develop a high-energy density primary battery with a minimum of 200 watt hours per pound of total battery weight third quarterly report, jan. - mar. 1965

Electrochemical study of prospective electrode- electrolyte systems for high-energy primary battery with minimum of 200 watt hours per pound of total battery weigh

A program to develop a high-energy density primary battery with a minimum of 200 watt hours per pound of total battery weight Fifth quarterly report, 1 Jul. - 30 Sep. 1965

High energy density primary battery development - electrochemical half-cell screening of anode- electrolyte combinations, cell discharge, and potential studie

A program to develop a high-energy density primary battery with a minimum of 200 watt hours per pound of total battery weight Seventh quarterly report, Jan. 1 - Mar. 31, 1966

Cathodic materials for high energy density storage batter

A program to develop a high-energy density primary battery with a minimum of 200 watt hours per pound of total battery weight Eighth quarterly report, 1 Apr. - 30 Jun. 1966

Electrochemical characteristics of lithium in various electrolytes and magnesium in aluminum chloride-acetonitrile studied by voltammetric sweep metho