Spectral control of laser oscillators by secondary light sources.
Frequency and polarization selection of neodymium glass laser oscillators by directing secondary radiation into laser cavity and duplicating spectral properties
Deshazer, L. G.↗
SEARCH · Search NASA
Results for “secondary control”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Thrust vector control apparatus Patent
Thrust vector control by secondary injection of fluid into rocket nozzle flow field to separate exhaust flow
Conrad, E. W.↗
Electrochemical coulometer and method of forming same Patent
Alkaline-type coulometer cell for primary charge control in secondary battery recharge circuits
Stroup, E. R.↗
Analysis of helicopter maneuver-loads and rotor-loads flight test data
A study was conducted in which available airload and blade response data for the NH-3A and CH-53A rotors were analyzed in an attempt to provide greater insight into the sources of rotor vibratory loads in both level and maneuvering flight. Primary emphasis in the study was placed on examining and understanding causes of high-frequency rotor control loads. Secondary objectives were: (1) to examine the effect of number of rotor blades on hub vibratory shear forces and (2) to assess which of the many terms appearing in the hub vibratory shear force expression were of most significance.
Beno, E. A.↗
Redundant actuator development study
Current and past supersonic transport configurations are reviewed to assess redundancy requirements for future airplane control systems. Secondary actuators used in stability augmentation systems will probably be the most critical actuator application and require the highest level of redundancy. Two methods of actuator redundancy mechanization have been recommended for further study. Math models of the recommended systems have been developed for use in future computer simulations. A long range plan has been formulated for actuator hardware development and testing in conjunction with the NASA Flight Simulator for Advanced Aircraft.
Ryder, D. R.↗
A study of low-cost reliable actuators for light aircraft. Part A: Chapters 1-8
An analysis involving electro-mechanical, electro-pneumatic, and electro-hydraulic actuators was performed to study which are compatible for use in the primary and secondary flight controls of a single engine light aircraft. Actuator characteristics under investigation include cost, reliability, weight, force, volumetric requirements, power requirements, response characteristics and heat accumulation characteristics. The basic types of actuators were compared for performance characteristics in positioning a control surface model and then were mathematically evaluated in an aircraft to get the closed loop dynamic response characteristics. Conclusions were made as to the suitability of each actuator type for use in an aircraft.
Eijsink, H.↗
JT8D-15/17 High Pressure Turbine Root Discharged Blade Performance Improvement
The JT8D high pressure turbine blade and seal were modified, using a more efficient blade cooling system, improved airfoil aerodynamics, more effective control of secondary flows, and improved blade tip sealing. Engine testing was conducted to determine the effect of these improvements on performance. The modified turbine package demonstrated significant thrust specific fuel consumption and exhaust gas temperature improvements in sea level and altitude engine tests. Inspection of the improved blade and seal hardware after testing revealed no unusual wear or degradation.
Janus, A. S.↗
Aerodynamics of advanced axial-flow turbomachinery
A multi-task research program on aerodynamic problems in advanced axial-flow turbomachine configurations was carried out at Iowa State University. The elements of this program were intended to contribute directly to the improvement of compressor, fan, and turbine design methods. Experimental efforts in intra-passage flow pattern measurements, unsteady blade row interaction, and control of secondary flow are included, along with computational work on inviscid-viscous interaction blade passage flow techniques. This final report summarizes the results of this program and indicates directions which might be taken in following up these results in future work. In a separate task a study was made of existing turbomachinery research programs and facilities in universities located in the United States. Some potentially significant research topics are discussed which might be successfully attacked in the university atmosphere.
Serovy, G. K.↗
Aircraft wing weight build-up methodology with modification for materials and construction techniques
An aircraft wing weight estimating method based on a component buildup technique is described. A simplified analytically derived beam model, modified by a regression analysis, is used to estimate the wing box weight, utilizing a data base of 50 actual airplane wing weights. Factors representing materials and methods of construction were derived and incorporated into the basic wing box equations. Weight penalties to the wing box for fuel, engines, landing gear, stores and fold or pivot are also included. Methods for estimating the weight of additional items (secondary structure, control surfaces) have the option of using details available at the design stage (i.e., wing box area, flap area) or default values based on actual aircraft from the data base.
York, P.↗
Primary electric power generation systems for advanced-technology engines
The advantages of the all electric airplane are discussed. In the all electric airplane the generator is the sole source of electric power; it powers the primary and secondary flight controls, the environmentals, and the landing gear. Five candidates for all electric power systems are discussed and compared. Cost benefits of the all electric airplane are discussed.
Cronin, M. J.↗
Geodetic measurement of deformation in the central Mojave Desert, California
Data from triangulation and trilateration surveys made during 1934-1982 are used to calculate shear strain rates in the central Mojave Desert of California. For the region between the Helendale and Camp Rock faults the shear strain rate was determined to be 0.16 + or - 0.03 microstrain/yr, with maximum right-lateral shear strain occurring on a plane oriented N41 deg W + or - 5 deg. If this deformation is due to right-lateral motion across the northwest trending local faults, the average shear straining corresponds to a relative displacement of 6.7 + or - 1.3 mm/yr across this portion of the network, accounting for about 12 percent of the predicted 56 mm/yr of relative motion between the North Atlantic and Pacific plates. From the Camp Rock fault eastward across the network there is a transition from significant to very low strain rates. Examination of nine focal mechanisms and their relation to the local geology and the strain data suggests that most of the long-term displacement occurs on the major northwest trending faults oriented nearly along the direction of relative motion between the North American and Pacific plates. Secondary faulting, controlled by a Coulomb-Anderson failure mechanism or by slip on preexisting faults can account for the occurrence of earthquakes on faults of other orientations.
Sauber, Jeanne↗
Greater Bone Fomation Induction Occurred in Aged Than Young Cancellous Bone Sites
We have determined the differences in the effects of continual prostaglandin E2 (PGE2) treatment in aged (non-growing) and young (growing) cancellous bone sites in 7 month-old Sprague-Dawley rats. The sites involved are the aged Distal Tibial Metaphysis (DTM) with a closed epiphysis and the young Proximal Tibial Metaphysis (PTM) with a slow growing, open epiphysis. The study involved rats treated with 0, 1, 3 or 6 mg PGE2/kg/d for 60, 120 and 180 days. Static and dynamic histomorphometty of percent trabecular area, and tissue-referent bone formation rate (BFR/TV) were determined in both DTM and PTM. In pretreatment controls, the secondary spongiosa of the two metaphyses contain the same amount of cancellous bone (11% in DTM vs. 13% in PTM), but markedly less bone formation in DTM (0.6%/y in DTM vs. 41.5%/y in PTM). After 60 days of 6 mg PGE2/kg/d treatment, %Tb.Ar was increased 607% in DTM and 199% in PTM, BFR/TV was increased to nearly 14 fold in DTM and only 5 fold in PTM. These results indicated the aged metaphysis of the DTM was much more responsive to PGE2 treatment than young, growing metaphysis of the PTM. The results of 120 and 180 days treatment did not significantly differ from 60 days treatment in both sites, indicating that the effect of continuous daily PGE2 treatment were in equilibrium after 60 days. We concluded that aged metaphysis was much more responsive to PGE2 treatment than young growing metaphysis.
Ke, H. Z.↗
Greater Bone Formation Induction Occurred in Aged than Young Cancellous Bone Sites
We have determined the differences in the effects of continual prostaglandin E(sub 2) (PGE(sub 2) treatment in aged (non-growing) and young (growing) cancellous bone sites in 7-month-old Sprague-Dawley rats. The sites involved are the aged distal tibial metaphysis (DTM) with a closed epiphysis and the young proximal tibial metaphysis (PTM) with a slow growing, open epiphysis. The study involved rats treated with 0, 1, 3 or 6 mg PGE(sub 2)/kg/d for 60, 120 and 180 days. Static and dynamic histomorphometry of percent trabecular area, and tissue-referent bone formation rate (BFR/TV) were determined in both DTM and PTM. In pretreatment controls, the secondary spongiosa of the two metaphyses contain the same amount of cancellous bone (11% in DTM vs. 13% in PTM), but markedly less bone formation in DTM (0.6%/y in DTM vs. 41.5%/y in PTM). After 60 days of 6 mg PGE(sub 2)/kg/d treatment, %Tb.Ar was increased 607% in DTM and 199% in PTM, BFR/TV was increased to nearly 14 fold in DTM and only 5 fold in PTM. These results indicated the aged metaphysis of the DTM was much more responsive to PGE(sub 2) treatment than young, growing metaphysis of the PTM. The results of 120 and 180 days treatment did not significantly differ from 60 days treatment in both sites, indicating that the effect of continuous daily PGE2 treatment were in equilibrium after 60 days. We concluded that aged metaphysis was much more responsive to PGE(sub 2) treatment than young growing metaphysis.
Ke, H. Z.↗
Management of Total Pressure Recovery, Distortion and High Cycle Fatigue in Compact Air Vehicle Inlets
It is the purpose of this study to demonstrate the viability and economy of Response Surface Methods (RSM) and Robustness Design Concepts (RDC) to arrive at micro-secondary flow control installation designs that maintain optimal inlet performance over a range of the mission variables. These statistical design concepts were used to investigate the robustness properties of 'low unit strength' micro-effector installations. 'Low unit strength' micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion.
Anderson, Bernhard H.↗
The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets
It is the purpose of this study to demonstrate the viability and economy of Design-of-Experiments methodologies to arrive at microscale secondary flow control array designs that maintain optimal inlet performance over a wide range of the mission variables and to explore how these statistical methods provide a better understanding of the management of flow in compact air vehicle inlets. These statistical design concepts were used to investigate the robustness properties of low unit strength micro-effector arrays. Low unit strength micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. The term robustness is used in this paper in the same sense as it is used in the industrial problem solving community. It refers to minimizing the effects of the hard-to-control factors that influence the development of a product or process. In Robustness Engineering, the effects of the hard-to-control factors are often called noise , and the hard-to-control factors themselves are referred to as the environmental variables or sometimes as the Taguchi noise variables. Hence Robust Optimization refers to minimizing the effects of the environmental or noise variables on the development (design) of a product or process. In the management of flow in compact inlets, the environmental or noise variables can be identified with the mission variables. Therefore this paper formulates a statistical design methodology that minimizes the impact of variations in the mission variables on inlet performance and demonstrates that these statistical design concepts can lead to simpler inlet flow management systems.
Anderson, Bernhard H.↗
Payload Operations Center - Lessons from Commercial Engagement
The International Space Station (ISS) Payload Operations and Integration Center (POIC) at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, United States, has gone through an evolution from supporting exclusively government ISS users to providing 50% (or more) of their support to commercial users. At the same time, they have expanded ground and facility operations to support a United States Orbital Segment crew expansion from three to four astronauts allowing an additional of 34 hours crew time per week. These additional hours are dedicated to utilization and have already surpassed the 100 hour peak weekly milestone in July 2018. This paper discusses the Center's changes in planning, staffing, coordination, and operations while addressing topics from the addition of secondary flight control positions to dynamic operations product reviews. MSFC's Human Exploration and Development Operations Office, which manages payload operations, seeks through this paper to highlight the higher priority commercial users now receive in replanning and in additional crew time.
Watkins, Bobby J.↗
MSR Curation Technology Development – Developing Protocols for Pre-Basic Characterization Measurements
The joint NASA/ESA Mars Sample Return (MSR) campaign could deliver to Earth the first pristine Mar-tian rock and regolith samples, collected by the Mars2020 science mission, Perseverance. In preparation for their arrival, the NASA/ESA Joint Curation Office (JCO) within the Sample Receiving Project (SRP) is developing curation technology needed to perform initial characterization of the samples while isolating samples from the Earth’s biosphere and protecting the samples from terrestrial contamination. (RSTA; Fig. 1). The Mars Sample Return Planning Group 2 (MSPG2) identified methods for achieving an array of potential science objectives for MSR outlined by the International MSR Objectives and Samples Team (iMOST) [1]. One category of methods, called Pre-Basic Characterization, recommends potential analyses that would happen before the Returnable Sample Tube Assemblies (RSTA; Figure 1) are opened: 1) Magnetometer & Magnetic Susceptibility; 2) X-ray Computed Tomography (XCT) Scanner [2]. To be in compliance with planetary protection requirements, and to limit the amount of time sample tubes are out-side of an isolated contamination-controlled environment, secondary containment is necessary. A Sample Tube Isolation Container (STIC) and Secondary Outer Containment Case (SOCC) is currently being developed at NASA JPL under the direction of the SRP JCO.
V Tu↗
Further Characterization of CELSS Wastes: A Review of Solid Wastes Present to Support Potential Secondary Biomass Production
Controlled ecological life support systems (CELSS) may one day play an essential role in extraterrestrial colonies. Key to the success of any CELSS will be the system's ability to approach a self-supporting status through recovery and reuse of basic resources. Primary CELSS solid wastes with potential to support secondary biomass production will be inedible plant biomass and metabolic human wastes. Solid waste production is summarized and reported as 765 g N per day per person, including 300 g C and 37 g N per day per person. One Resource Recovery configuration using the bioprocessing of solid wastes into a Tilapia feed stream is examined. Based on estimated conversion efficiencies, 12 g of protein per day per person is produced as a nutrition supplement. The unique tissue composition of crops produced at the Kennedy Space Center CELSS Program highlights the need to evaluate Resource Recovery components with data generated in the CELSS environment.
Muller, Matthew S.↗