Influences in the selection of a cycle for small high speed engines running on solid or airless injection with compression ignition
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Matthews, Robertson↗
SEARCH · Engineering Papers
Results for “RuN”
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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Experimental Verification of Two Methods for Computing the Take-off Ground Run of Propeller-driven Aircraft
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Gasich, Welko E↗
Deflection of Propeller Blades While Running
The forces acting on the blades of a propeller proceed from the mass of the propeller and the resistance of the surrounding medium. The magnitude, direction and point of application of the resultant to the propeller blade is of prime importance for the strength calculation. Since it was obviously impracticable to bring any kind of testing device near the revolving propeller, not so much on account of the element of danger as on account of the resulting considerable disturbance of the air flow, the deflection in both cases was photographically recorded and subsequently measured at leisure.
PROPELLERS - DEFLECTION↗
Calculated effect of some airplane handling techniques on the ground-run distance in landing on slippery runways
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Zalovik, John A↗
Screen-type Noise Reduction Devices for Ground Running of Turbojet Engines
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Coles, Willard D↗
Experiments with a device for shortening the glide and landing run of an airplane
The improvement of airplanes and increased safety of air traffic can be sought in various ways. In the experiments described below, the aim was to find some simple and inexpensive method of modifying present-day airplanes, so as to improve and simplify the process of landing.
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Tabulated pressure coefficients and aerodynamic characteristics measured in flight on the wing of the Douglas D-558-I airplane for a 1 g stall, a speed run to a Mach number of 0.90, and a wind-up turn at a Mach number of 0.86
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Keener, Earl R↗
A Computer Program for the Computation of Running Gear Temperatures Using Green's Function
A new technique has been developed to study two dimensional heat transfer problems in gears. This technique consists of transforming the heat equation into a line integral equation with the use of Green's theorem. The equation is then expressed in terms of eigenfunctions that satisfy the Helmholtz equation, and their corresponding eigenvalues for an arbitrarily shaped region of interest. The eigenfunction are obtalned by solving an intergral equation. Once the eigenfunctions are found, the temperature is expanded in terms of the eigenfunctions with unknown time dependent coefficients that can be solved by using Runge Kutta methods. The time integration is extremely efficient. Therefore, any changes in the time dependent coefficients or source terms in the boundary conditions do not impose a great computational burden on the user. The method is demonstrated by applying it to a sample gear tooth. Temperature histories at representative surface locatons are given.
GREENS FUNCTIONS↗
Take-off Distances of a Supersonic Transport Configuration as Affected by Airplane Rotation During the Take-off Run
The take-off distances over a 35-foot obstacle have been determined for a supersonic transport configuration characterized by a low maximum lift coefficient at a high angle of attack and by high drag due to lift. These distances were determined analytically by means of an electronic digital computer. The effects of rotation speed, rotation angle, and rotation time were determined. A few configuration changes were made to determine the effects of thrust-weight ratio, wing loading, maximum lift coefficient, and induced drag on the take-off distance. The required runway lengths based on Special Civil Air Regulation No. SR-422B were determined for various values of rotation speed and compared with those based on full engine power. Increasing or decreasing the rotation speed as much as 5 knots from the value at which the minimum take-off distance occurred increased the distance only slightly more than 1 percent for the configuration studied. Under-rotation by 1 deg to 1.5 deg increased the take-off distance by 9 to 15 percent. Increasing the time required for rotation from 3 to 5 seconds had a rather small effect on the take-off distance when the values of rotation speed were near the values which result in the shortest take-off distance. When the runway length is based on full engine power rather than on SR-422B, the rotation speed which results in the shortest required runway length is 10 knots lower and the runway length is 4.3 percent less.
Hall, Albert W.↗
Profile of Ambulance Runs at the Kennedy Space Center
The Kennedy Space Center (KSC) has four onsite ambulances staffed with Paramedics at two fire stations that respond to 911 Emergency Medical System (EMS) medical dispatches. These ambulances serve over 22,000 NASA, military, government, and contractor employees in an area of approximately 520 square miles. Included in this coverage are several public areas such as beaches, a wildlife refuge and a popular Visitor Center. Reports are filled out on each patient encountered. However. the only element tracked has been the ambulance response time. Now that reports are filed electronically, it is possible to enter them into an electronic database for analysis. Data analyses reveal trends and assist in better allocation of resources.
Scarpa, Philip J.↗
Experimental Studies of Brines and Evaporites as Applied to Mars: Initial Results from 1998-1999 Runs
We are performing laboratory experiments to determine the concentrations and rates of dissolution of ions that could occur in closed, juvenile groundwater systems on Mars. Our approach is to incubate unaltered Mars-analog minerals in initially pure liquid water in contact with a Mars gas mixture for one year. At exponentially increasing time intervals, aliquots of the solutions at three different temperatures are extracted and analyzed using standard terrestrial laboratory geochemical techniques. Ultimately, our experiments will produce Mars analog brines which will be freeze dried to create evaporites. The physical and chemical properties of these evaporites will be compared with spacecraft remote sensing and in situ compositional and physical data. Additional information is contained in the original extended abstract.
Moore, J. M.↗
Predictability of the 1997 and 1998 South Asian Summer Monsoons on the Intraseasonal Time Scale Based on 10 AMIP2 Model Runs
Predictability of the 1997 and 1998 South Asian summer monsoons is examined using National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalyses, and 100 two-year simulations with ten different Atmospheric General Circulation Models (AGCMs) with prescribed sea surface temperature (SST). We focus on the intraseasonal variations of the south Asian summer monsoon associated with the Madden-Julian Oscillation (MJO). The NCEP/NCAR reanalysis shows a clear coupling between SST anomalies and upper level velocity potential anomalies associated with the MJO. We analyze several MJO events that developed during the 1997 and 1998 focusing of the coupling with the SST. The same analysis is carried out for the model simulations. Remarkably, the ensemble mean of the two-year AGCM simulations show a signature of the observed MJO events. The ensemble mean simulated MJO events are approximately in phase with the observed events, although they are weaker, the period of oscillation is somewhat longer, and their onset is delayed by about ten days compared with the observations. Details of the analysis and comparisons among the ten AMIP2 (Atmospheric Model Intercomparison Project) models will be presented in the conference.
Wu, Man Li C.↗
Robustness via Run-Time Adaptation of Contingent Plans
In this paper, we discuss our approach to making the behavior of planetary rovers more robust for the purpose of increased productivity. Due to the inherent uncertainty in rover exploration, the traditional approach to rover control is conservative, limiting the autonomous operation of the rover and sacrificing performance for safety. Our objective is to increase the science productivity possible within a single uplink by allowing the rover's behavior to be specified with flexible, contingent plans and by employing dynamic plan adaptation during execution. We have deployed a system exhibiting flexible, contingent execution; this paper concentrates on our ongoing efforts on plan adaptation, Plans can be revised in two ways: plan steps may be deleted, with execution continuing with the plan suffix; and the current plan may be merged with an "alternate plan" from an on-board library. The plan revision action is chosen to maximize the expected utility of the plan. Plan merging and action deletion constitute a more conservative general-purpose planning system; in return, our approach is more efficient and more easily verified, two important criteria for deployed rovers.
Bresina, John L.↗
What to Do Until the Money Runs Out: A Refinement Framework for Cognitive Engineering in the Real World
A case study is presented to illustrate some of the problems of applying cognitive science to complex human-machine systems. Disregard for facts about human cognition often undermines the safety, reliability, and cost-effectiveness of complex systems. Yet single-point methods (for example, better user-interface design), whether rooted in computer science or in experimental psychology, fall far short of addressing systems-level problems in a timely way using realistic resources. A model-based methodology is proposed for organizing and prioritizing the cognitive engineering effort, focusing appropriate expertise on major problems first, then moving to more sophisticated refinements if time and resources permit. This case study is based on a collaborative effort between the Human Factors Division at NASA-Ames and the Spaceborne Imaging Radar SIR-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) Project at the Jet Propulsion Laboratory (JPL), California institute of Technology. The first SIR-C/X-SAR Shuttle mission flew successfully in April, 1994. A series of such missions is planned to provide radar data to study Earth's ecosystems, climatic and geological processes, hydrologic cycle, and ocean circulation. In addition to JPL and NASA personnel, the SIR-C/X-SAR operations team included Scientists and engineers from the German and Italian space agencies.
Shafto, Michael G.↗
Comparison of Mean Climate Trends in the Northern Hemisphere Between N.C.E.P. and Two Atmosphere-Ocean Model Forced Runs
Results are presented for two greenhouse gas experiments of the Goddard Institute for Space Studies Atmosphere-Ocean Model (AOM). The computed trends of surface pressure, surface temperature, 850, 500 and 200 mb geopotential heights and related temperatures of the model for the time frame 1960-2000 are compared to those obtained from the National Centers for Environmental Prediction observations. A spatial correlation analysis and mean value comparison are performed, showing good agreement. A brief general discussion about the statistics of trend detection is presented. The domain of interest is the Northern Hemisphere (NH) because of the higher reliability of both the model results and the observations. The accuracy that this AOM has in describing the observed regional and NH climate trends makes it reliable in forecasting future climate changes.
Lucarini, Valerio↗
North American Observing Systems: An Interagency Group Runs Tests at the NCCS
Some 250,000 weather reports are collected by the National Weather Service (NWS) every day. Important measurements are taken by satellites, weather balloons, ground weather stations, airplanes, oceangoing ships, and tethered ocean buoys. Local or global weather models rely on these reports to provide the raw data used as initial conditions for the models to produce a weather prediction.
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Biomechanics of walking and running: center of mass movements to muscle action
No abstract available
Non-NASA Center↗
LIFT Tenant Is Off and Running
Lewis Incubator for Technology (LIFT) tenant, Analiza Inc., graduated from the incubator July 2000. Analiza develops technology and products for the early diagnosis of diseases, quality control of bio-pharmaceutical therapeutics, and other applications involving protein analyses. Technology links with NASA from existing and planned work are in areas of microfluidics and laser light scattering. Since their entry in LIFT in May, 1997, Analiza has: Received a $750,000 grant from the National Institutes of Health. Collaborated with a Nobel Prize winner on drug design. Collaborated with Bristol-Myers Squibb on the characterization of biological therapeutics. Added a Ph.D. senior scientist and several technicians. Received significant interest from major pharmaceutical companies about collaborating and acquiring Analiza technology.
Steele, Gynelle C.↗