Theoretical analysis of incompressible flow through a radial-inlet centrifugal impeller at various weight flows (open access)

Theoretical analysis of incompressible flow through a radial-inlet centrifugal impeller at various weight flows

A method for the solution of the incompressible nonviscous flow through a centrifugal impeller, including the inlet region, is presented. Several numerical solutions are obtained for four weight flows through an impeller at one operating speed. These solutions are refined in the leading-edge region. The results are presented in a series of figures showing streamlines and relative velocity contours. A comparison is made with the results obtained by using a rapid approximate method of analysis.
Date: March 4, 1955
Creator: Kramer, James J.; Prian, Vasily D. & Wu, Chung-Hua
System: The UNT Digital Library
A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction (open access)

A Theoretical Investigation of the Lateral Oscillations of an Airplane With Free Rudder With Special Reference to the Effect of Friction

"Charts showing the variation in dynamic stability with the rudder hinge-moment characteristics are presented. A stabilizing rudder floating tendency combined with a high degree of aerodynamic balance is shown to lead to oscillations of increasing amplitude. This dynamic instability is increased by viscous-friction in the rudder control system" (p. 147).
Date: March 4, 1943
Creator: Greenberg, Harry & Sternfield, Leonard
System: The UNT Digital Library
Pressure-sensitive system for gas-temperature control (open access)

Pressure-sensitive system for gas-temperature control

From Summary: "A thermodynamic relation is derived and simplified for use as a temperature-limiting control equation involving measurement of gas temperature before combustion and gas pressures before and after combustion. For critical flow in the turbine nozzles of gas-turbine engines, the control equation is further simplified to require only measurements upstream of the burner. Hypothetical control systems are discussed to illustrate application of the control equations."
Date: March 4, 1948
Creator: Cesaro, Richard S. & Matz, Norman
System: The UNT Digital Library
Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results (open access)

Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results

"An analysis is made of the structural response to gusts of an airplane having the degrees of freedom of vertical motion and wing bending flexibility and basic parameters are established. A convenient and accurate numerical solution of the response equations is developed for the case of discrete-gust encounter, an exact solution is made for the simpler case of continuous-sinusoidal-gust encounter, and the procedure is outlined for treating the more realistic condition of continuous random atmospheric turbulence, based on the methods of generalized harmonic analysis. Correlation studies between flight and calculated results are then given to evaluate the influence of wing bending flexibility on the structural response to gusts of two twin-engine transports and one four-engine bomber" (p. 1).
Date: March 4, 1954
Creator: Houbolt, John C. & Kordes, Eldon E.
System: The UNT Digital Library
A theoretical study of lateral stability with an automatic pilot (open access)

A theoretical study of lateral stability with an automatic pilot

"The influence of automatic operation of the aileron and rudder controls on the lateral stability of an airplane is discussed. The control deflections are assumed to be proportional to the deviations and to the rates of deviation of the airplane from steady-flight conditions. The effects of changes in the types of deviation governing control application are considered. For one simple method of control in which the aileron deflection is proportional to the angle of bank and the rudder deflection is proportional to the angle of yaw, the effect of lag in control application is studied and regions of stability with and without lag are given" (p. 273).
Date: March 4, 1940
Creator: Imlay, Frederick H.
System: The UNT Digital Library
Span-load distribution as a factor in stability in roll (open access)

Span-load distribution as a factor in stability in roll

"This report gives the results of pressure-distribution tests made to study the effects on lateral stability of changing the span-load distribution on a rectangular monoplane wing model of fairly thick section. Three methods of changing the distribution were employed: variation in profile along the span to a thin symmetrical section at the tip, twist from +5 degrees to -15 degrees at the tip, and sweepback from +20 degrees to -20 degrees. The tests were conducted in a 5-foot closed-throat atmospheric wind tunnel" (p. 567).
Date: March 4, 1931
Creator: Knight, Montgomery & Noyes, Richard W.
System: The UNT Digital Library