Research program on the organization and management of research and development. Questioning the cost/effectiveness of the R and D procurement process
Cost-effectiveness evaluation of Research and Development process
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SEARCH · Engineering Papers
Results for “Effectiveness evaluation”
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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Wave-Plan Analysis of Unsteady Flow
An analytical method for computing unsteady flow conditions in liquid-filled flow systems is developed. The method which is called the wave plan incorporates distributed parameter and nonlinear effects including the effects of viscous resistance. The wave plan is essentially a solution synthesized from the effects of incremental step pressure pulses. The pressure pulses are generated because of incremental flow-rate changes that originate in a hydraulic system from a variety of sources, including the mechanical motion of the system structure. The pressure pulses propagate throughout the system at sonic velocity and are partially transmitted and reflected at each discontinuity. The velocity change caused by each pressure pulse is obtained from the Joukowski relation. Pressure and velocity time histories at any point in the system are obtained by a timewise summation of the contributions of the incremental pressure pulses passing that point. The analysis is presented in a form general enough to be applied to a variety of hydraulic systems. To illustrate the application of the method to a specific system, the response of a straight hydraulic line to a sinusoidal orifice-area variation of an upstream valve is computed. Both a constant-cross- section line and a tapered line are analyzed in the examples, and various nonlinear effects evaluated. Comparisons are carried out with experimental data obtained for the constant-diameter line and good agreement is shown to exist.
UNSTEADY FLOW↗
Effects of the plasma sheath on antenna performance
Slotted antenna radiation patterns and near field effects evaluated by solving aperture and plasma problems
PLASMA FREQUENCY↗
Effective screening of integrated circuits.
Automated DC pin to pin test method for effective evaluation and screening of integrated circuits
Thomas, E. F., Jr.↗
Quasi-optimum design of an aircraft landing control system.
Quasi-optimum control law for aircraft landing control system design based on Friedland technique, evaluating effectiveness by computer simulation
Ling, C. K.↗
Biological handbook for engineers
Microbiological background information is compiled in handbook for engineers and scientists working on bio-related projects. It is intended as aid in - /1/ evaluating effects of engineering procedures on microbial life, /2/ determining effects of decontamination and sterilization on performance of overall systems, and /3/ understanding language of microbiologists.
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The rheological behavior of lubricants
Rheological models for evaluating effects of lubricant film thickness and frictional traction
Naylor, H.↗
Aircraft response to the wing trailing vortices generated by large jet transports
Flight tests for evaluating effect of wing-tip vortex wake generated by large jet transports on smaller aircraft
Andrews, W. H.↗
Derivative approximation for recursive signal detection
Derivative approximation techniques for recursive signal detection, using computer program for solving optimum and suboptimum processes signal to noise ratio in effectiveness evaluation
Boorstyn, R. R.↗
Biowaste resistojet propellant system biological and functional analysis, task 3
Exhaust flow contamination aspects of the biowaste resistojet are studied by evaluating effects of operating pressure, temperature and composition. Biowaste propellant mixtures considered are comprised of: (1) The Sabatier reactor effluent; (2) the effluent of the cabin carbon dioxide molecular sieve; and (3) water and water vapor from various sources. Results show that plume shapes of resistojet thrusters in the 25 to 100 mlb range exhibit greater apex angles for a given density contour than a scaled inviscid jet. Operation at low thrust, low pressure and high temperature accentuates this pluming due to viscous effects in the nozzle flow. Since the biowaste resistojet effluent is traveling at high velocity in the plume away from the aircraft it is found to be a superior method of damping than the ambient venting.
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Development of space stable thermal control coatings for use on large space vehicles
A reserach project to develop space stable thermal control coatings for large surfaces is discussed. Four major tasks are considered: (1) pigment development, (2) binder development, (3) environmental effects evaluations, and (4) general coatings investigations.
Gilligan, J. E.↗
A forebody design technique for highly integrated bottom-mounted scramjets with application to a hypersonic research airplane
An inviscid technique for designing forebodies which produce uniformly precompressed flows at the inlet entrance for bottom-mounted scramjets has been developed so that geometric constraints resulting from design trade-offs can be effectively evaluated. The flow fields resulting from several forebody designs generated in support of a hypersonic research airplane conceptual design study have been analyzed in detail with three-dimensional characteristics calculations to verify the uniform flow conditions. For the designs analyzed, uniform flow is maintained over a wide range of flight conditions (Mach number equals 4 to 10; angle of attack equals 6 deg to 10 deg) corresponding to scramjet operation flight envelope of the research airplane.
Edwards, C. L. W.↗
Development of space stable thermal control coatings for use on large space vehicles
Pigment manufacturing development, binder development, environmental effects evaluations, and general coatings investigations are discussed. The relative emphasis on each of these tasks varied according to the urgency of the problems elucidated and the availability of time and funds. Emphasis is placed on the development of a mixed oxalate precursor zinc orthotitanate pigment manufacturing method and related studies and on complementary environmental testing and evaluation activities.
Harada, Y.↗
A forebody design technique for highly integrated bottom-mounted scramjets with application to a hypersonic research airplane
A rapid and simple inviscid technique for designing forebodies which produce uniformly precompressed flows at the entrance for bottom-mounted scramjets was developed so that geometric constraints resulting from design trade-offs can be effectively evaluated. The flow fields resulting from several forebody designs generated in support of a conceptual design for a hypersonic research airplane have been analyzed in detail. Three-dimensional characteristics calculations were used to verify the uniform flow conditions. For the designs analyzed, uniform flow was maintained over a wide range of flight conditions (Mach numbers from 4 to 10; angles of attack of 6 and 10 deg) corresponding to the scramjet operation flight envelope of the research airplane.
Edwards, C. L. W.↗
Accelerated-weathering test-system for solar cells
Test system rapidly evaluates effects of sunlight, humidity, and temperature. System accelerates environmental testing since Sunlight is held at equivalent noon exposure (for a selected locality) for 12 hours; alternating light and dark periods are included to check for possible dark reactions in specimens.
Kolyer, J. M.↗
Investigation of steady and fluctuating pressures associated with the transonic buffeting and wing rock of a one-seventh scale model of the F-5A aircraft
A wind tunnel test of a 1/7 scale F-5A model is described. The pressure, force, and dynamic response measurements during buffet and wing rock are evaluated. Effects of Mach number, angle of attack, sideslip angle, and control surface settings were investigated. The mean and fluctuating static pressure data are presented and correlated with some corresponding flight test data of a F-5A aircraft. Details of the instrumentation and the specially designed support system which allowed the model to oscillate in roll to simulate wing rock are also described. A limit cycle mechanism causing wing rock was identified from this study, and this mechanism is presented.
Hwang, C.↗
NASCAP modelling of environmental-charging-induced discharges in satellites
The charging and discharging characteristics of a typical geosynchronous satellite experiencing time-varying geomagnetic substorms, in sunlight, were studied utilizing the NASA Charging Analyzer Program (NASCAP). An electric field criteria of 150,000 volts/cm to initiate discharges and transfer of 67 percent of the stored charge was used based on ground test results. The substorm characteristics were arbitrarily chosen to evaluate effects of electron temperature and particle density (which is equivalent to current density). It was found that while there is a minimum electron temperature for discharges to occur, the rate of discharges is dependent on particle density and duration times of the encounter. Hence, it is important to define the temporal variations in the substorm environments.
Stevens, N. J.↗
JANTX1N2970B zener diode
Report evaluates effects of power and temperature overstress on General Semi-conductor and Siemens devices. Excessive failure rates limited testing. Failure modes are described.
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