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Viewing 1 to 21 of 21
1998-07-13
Technical Paper
981669
Siraj A. Jalali, Richard G. Stinson
In this investigation, analytical models were developed to predict the performance characteristics of axisymmetric single jet ejector. The ejector is divided into four parts, jet, mixer, nozzle, and diffuser. Basic flow equations were combined to calculate end to end flow characteristics for each of the four ejector components. Different jets and mixer combination were tested using three jet and three mixers. Characteristics curves have been drawn to predict flow characteristics of the ejector. Different configuration of jet and mixer incorporated different loss coefficient. Hence to get correct flow characteristics of the ejector right loss coefficient should be used.
1998-07-13
Technical Paper
981670
Siraj A. Jalali, Scott J. Andrea
An experimental study has been made of compressible jet mixing in an axisymmetric ejector of converging-diverging geometry. Three different jet sizes, 0.01, 0.0235, and 0.045 in. diameter were tested with three different mixer sizes, 0.25, 0.286, and 0.36 in. diameter. Jet and mixer combination were tested along with varying jet to mixer distances. The jet pressure varied from 20 to 200 psig, jet mass varied from 0.3 lbm/hr to 10 lbm/hr., and jet temperature varied from 21 to 24 deg. F. The secondary loop pressure varied from 3.7 to 25 psia, secondary mass flow varied from 1 to 70 lbm/hr, secondary loop pressure drop varied from 4 inH20 to 10 inH20, and secondary loop temperature varied same as jet temperature. The mass flow ratio was in the range of 2 to 14. The results were analyzed and compared with the Hickman and Nuckols and Sexton prediction models. The loss factor in Nuckols and Sexton model was adjusted to match the test results.
2006-09-12
Technical Paper
2006-01-3179
R. J. Bucci, M. A. James, H. Sklyut, M. B. Heinimann, D. L. Ball, J. K. Donald
Significant system efficiency gains can be achieved in high-performance aircraft via a unitized structure that reduces parts count. For instance, reduced parts count leads to substantial engineering logistic cost savings through higher levels of subsystem and mounting hardware integration. It also creates performance benefits by eliminating structural connections. Residual stress management, however, remains a major obstacle to capturing full benefits and broadening the application of unitized structure solutions. This paper describes how Alcoa and others are developing tools to overcome limitations in current testing, evaluation, and design practices attributed to residual stress effects. The authors present recent advancements in fracture toughness and fatigue crack growth characterization, along with a new, integrated approach for improved accounting of residual stress effects during fracture critical component design, manufacturing planning, and life management.
2007-07-09
Technical Paper
2007-01-3223
James F. Russell, Robyn L. Carrasquillo
Spacecraft hardware trade studies compare options primarily on mass while considering impacts to cost, risk, and schedule. Historically, other factors have been considered in these studies, such as reliability, technology readiness level (TRL), volume and crew time. In most cases, past trades compared two or more technologies across functional and TRL boundaries, which is an uneven comparison of the technologies. For example, low TRL technologies with low mass were traded directly against flight-proven hardware without consideration for requirements and the derived architecture. To provide for even comparisons of spacecraft hardware, trades need to consider functionality, mission constraints, integer vs. real number of flight hardware units, and mass growth allowances by TRL.
2008-11-11
Journal Article
2008-01-2863
Keith Bridger, Arthur Cooke, Walter Schulze, James Weigner, Scott Sentz, Mike Stewart, Frank Duva
This paper describes the development of a lead free, high temperature ceramic capacitor material having the base composition of (Na0.5 Bi0.5) TiO3. The goal is to modify this structure to create a material that has the relative permittivity of barium titanate with extended X7R-like properties to 250°C - an X14R. After an extensive compositional and theoretical modeling investigation a composition was selected and capacitors developed. The dielectric has a 1-kHz relative permittivity of ∼1200 with <±15% variation from -25 to +250°C and <5% loss from -55 to +250°C. These capacitors also have very low voltage coefficients, indeed they are positive at the low end of the temperature range, resulting in a combined TC-Vc capacitance variation 0%/-25% of nominal from -55 to +200°C with applied voltage stress from 20 to 260 V/mil.
2001-06-26
Technical Paper
2001-01-2099
James C. Maida, L. Javier Gonzalez, Sudhakar Rajulu, Erica Miles
To work outside a space craft, humans must wear a protective suit. The required suit pressurization creates additional resistance for the wearer while performing work. How much does the suit effect work and fatigue? To answer these questions, dynamic torque was collected for the shoulder, elbow and wrist for six subjects in an Extra-vehicular Mobility Unit (EMU). In order to quantify fatigue, the subjects were to exert maximum voluntary torque for five minutes or until their maximum fell below 50% of their initial maximum for three consecutive repetitions. Using the collected torque and time data, logarithmic based functions were derived to estimate torque decay to within an absolute error of 20%. These results will be used in the development of a generalized tool for prediction of maximum available torque over time for humans using the current EMU.
2010-07-26
Article
Goodrich Corp. signed a memorandum of agreement (MOA) with Lockheed Martin Aeronautics to design and develop polymer matrix composite (PMC) landing-gear drag braces for the F-35 Lightning II. In addition, Goodrich signed an MOA with Netherlands-based Fokker Landing Gear for the supply of PMC drag braces for the F-35's main landing gear.
2010-04-23
Article
The Lockheed Martin-led team developing the Orion crew exploration vehicle has completed fabrication of the world’s largest heat shield structure. The high-temperature composite material system, which is also suitable for commercial applications such as automobiles and heavy vehicles, was developed by the Lockheed Martin Orion thermal protection system team in partnership with TenCate Advanced Composites.
2009-09-14
Article
The Helicopters Division of Kaman Aerospace Corp. has been awarded a five-year contract with a potential value of $53 million to build composite helicopter blade skins and skin core assemblies for Bell Helicopters.
2008-06-30
Article
Lockheed Martin is drawing upon its experience in the practical use of advanced metals to make a number of significant improvements to the manufacturability and supportability of its three most important aircraft: the C-130J, F-22, and F-35.
2008-06-30
Article
Lockheed Martin signed an exclusive international rights agreement to integrate and market Electrical Energy Storage Units (EESUs) from Cedar Park, TX-based EEStor for military and homeland-security applications.
2017-06-10
Article
Metamaterial Technologies looks to enter the solar power market by providing advanced photovoltaic technology to the aerospace and defense industry.
2013-03-08
Article
Lockheed Martin and Singapore's Nanyang Technological University (NTU) signed a memorandum of understanding (MOU) to explore the science of nanotechnology, with special focus on nanocopper and related technologies for the commercial market.
2010-06-08
Article
Applied NanoStructured Solutions LLC (ANS), a subsidiary of Lockheed Martin Corp., and Owens Corning signed a joint development agreement to combine the carbon infusion technology of ANS with Owens Corning's reinforcements expertise to create a family of next-generation composite materials.
2010-05-07
Article
Lockheed Martin awarded Alliant Techsystems (ATK) a contract in excess of $240 million to produce additional composite components for low-rate initial production (LRIP) lots 4-8 of the F-35 Lightning II.
2010-04-26
Article
A. M. Castle & Co., a global distributor of specialty metal and plastic products, value-added services, and supply chain solutions, signed a memorandum of agreement with Lockheed Martin to enter into a six-year contract extension for the F-35 Joint Strike Fighter (JSF) program.
2011-05-04
Article
ATK has received a $110 million contract from Lockheed Martin to produce composite components for low rate initial production (LRIP) Lots 5 through 9 of the F-35 Lightning II—Joint Strike Fighter. The contract includes production of multiple components through the LRIP 9 phase of the program.
2012-01-06
Article
Insulating films and tapes supplied by Dunmore Corp. are providing protection from thermal damage and magnetic interference for the electronic systems on board NASA’s Juno probe, which was launched from Cape Canaveral Air Force Station in Florida on Aug. 5.
2008-06-30
Article
Breaking the mold is the USAF’s newest X-plane, the Advanced Composite Cargo Aircraft (ACCA). Lockheed Martin will build the ACCA, which will be based on a Fairchild Dornier 328J regional jet that will have its aluminum mid/aft fuselage and empennage replaced by sections built of advanced composites.
2010-01-27
Article
The success of the initial flight demonstrations of the Advanced Composite Cargo Aircraft (ACCA) prompted the U.S. Air Force late last year to officially designate the ACCA as the X-55A. In June 2009, the Air Force Research Laboratory and Lockheed Martin completed the first flight demonstration of the X-55A, establishing basic handling qualities and monitoring structural performance and response to load maneuvering—assessments relying on a network of approximately 600 sensors (strain gauges and accelerometers) integrated within the airframe. 
2010-08-20
Article
Lockheed Martin has signed a nonexclusive licensing agreement with Ceradyne Inc. for the development, manufacture, and application of the Lockheed Martin-developed TekShield lightweight, opaque ceramic armor.
Viewing 1 to 21 of 21

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