A Survey of Stability Analysis Techniques for Automatically Controlled Aircraft

A Survey of Stability Analysis Techniques for Automatically Controlled Aircraft

Author: Arthur L. Jones

Publisher:

Published: 1951

Total Pages: 120

ISBN-13:

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A survey of the stability analysis techniques for automatically controlled aircraft is presented. The survey is limited to techniques commonly applied to linear, continuous-control systems wherein the difference between the output and input quantities is measured continuously and is used in the operation of the system (a closed-loop system). An evaluation of the techniques, based on the kind and amount of information derivable, is included. An illustrative example is also presented to demonstrate the calculations involved for a typical aircraft-autopilot combination.


Report

Report

Author: United States. National Advisory Committee for Aeronautics

Publisher:

Published: 1952

Total Pages: 48

ISBN-13:

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Effect of Ice and Frost Formations on Drag of NACA 651-212 Airfoil for Various Modes of Thermal Ice Protection

Effect of Ice and Frost Formations on Drag of NACA 651-212 Airfoil for Various Modes of Thermal Ice Protection

Author: Vernon H. Gray

Publisher:

Published: 1953

Total Pages: 720

ISBN-13:

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The effects of primary and runback icing and frost formations on the drag of an 8-foot-chord NACA 651-212 airfoil section were investigated over a range of angles of attack from 2 degrees to 8 degrees and airspeeds up to 260 miles per hour for icing conditions with liquid-water contents ranging from 0.25 to 1.4 grams per cubic meter and datum air temperatures of -30 to 30 degrees F.


Electrical Techniques for Compensation of Thermal Time Lag of Thermocouples and Resistance Thermometer Elements

Electrical Techniques for Compensation of Thermal Time Lag of Thermocouples and Resistance Thermometer Elements

Author: Charles E. Shepard

Publisher:

Published: 1952

Total Pages: 740

ISBN-13:

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Basic electrical networks are described that compensate for the thermal time lag of thermocouple and resistance thermometer elements. For a given set of operating conditions, networks requiring no amplifiers can provide a thirtyfold reduction in effective time lag. This improvement is obtained without attenuation of the voltage signal, but does result in a large reduction in the amount of electric power available because of an increase in the output impedance of the network. Networks used commercially available amplifiers can provide a thousandfold reduction in the effective time lag without attenuation of the alternating voltage signal or or the available electric power, but the improvement is often obtained at the expense of loss of the zero-frequency signal. The completeness of compensation is limited by the extent of off-design operation required.