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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Digital computer program using influence coefficients method for optimizing camber surfaces for wing-body combinations at supersonic speeds
This paper presents the initial results of a digital computer study of helicopter rotor-blade-motion stability for a broad range of forward speeds encompassing proposed conventional and compound helicopter designs. The analysis treats the general case of nonlinear, coupled flapping and lagging motions of hinged rigid blades. The results of the study to date indicate that blade-motion stability boundaries cannot be specified for a given blade design in terms of a fixed value of rotor tip-speed ratio. The stability boundaries can shift significantly within the desired operational speed range, with the stability limits depending upon the rotor loading, the magnitude of the disturbance encountered by the blade, and the blade position at the instant the external disturbance is encountered. The sample methods suggested for improving blade-motion stability include increasing the effective hinge spring restraint by incorporating pitch-flap coupling or by using hingeless or teetering rotor systems. Reducing rotor loading also has a beneficial effect on the blade-motion stability. The results indicate that methods used to deal with the blade-motion stability problem can be expected to diminish the overall vibration levels of the helicopter rotor system across the entire design speed range.
Digital computer program for nonlinear equation sets characteristic of filter circuit analysis
In accomplishing the Gemini Program objectives, an onboard digital computer system, an inertial platform reference system, a radar system, and control systems using hypergolic bipropellant propulsion have been developed and successfully demonstrated.
Digital computer program for numerical solution of problems in system theory involving linear mathematics
Fortran IV IBM 7094 digital computer code to unfold bremsstrahlung photon distributions recorded by scintillation spectrometer
Matrix numerical procedure by digital computer equipment, and application to elastic stability and deflection problems
Users manual for general purpose digital computer program for predicting dynamic response of cylinders subjected to ramp and sinusoidal pressure transients
Digital computer program for ascertaining accuracy of lunar beacon location
Arbitrary quasi-orthogonals for calculating flow distribution in turbomachine, noting digital computer calculations
Digital computer determination of coefficients of transfer function from impulse response in time domain
Matrix form of Routh algorithm and invariance principle used in digital computer construction of root locus of system
Arbitrary quasi-orthogonals for calculating flow distribution in turbomachine, noting digital computer calculations
Computer controlled digital display techniques for direct editing of research data
Alouette I topside ionograms analyzed, discussing mathematical procedures and digital computer programs in use and orbit and electron density profiles
Read-only digital computer memory utilizing loom to braid information into wire harness
Structural Analysis and Matrix Interpretive System eliminates high-speed digital computer restrictions of lack of generalization and lack of flexibility. Programming concepts of the system are standardization, modularity, and programming for intermediate-size problems.
General purpose digital computer program is applicable for use with analysis programs that require basic data and calculated parameters as input. It is designed to automate input data preparation for flight control computer programs, but it is general enough to permit application in other areas.