4,675 research outputs found
Automatic controls and regulators: A compilation
Devices, methods, and techniques for control and regulation of the mechanical/physical functions involved in implementing the space program are discussed. Section one deals with automatic controls considered to be, essentially, start-stop operations or those holding the activity in a desired constraint. Devices that may be used to regulate activities within desired ranges or subject them to predetermined changes are dealt with in section two
Design and development of the quad redundant servoactuator for the space shuttle solid rocket booster thrust vector control
The design and theory of operation of the servoactuator used for thrust vector control of the space shuttle solid rocket booster is described accompanied by highlights from the development and qualification test programs. Specific details are presented concerning major anomalies that occurred during the test programs and the corrective courses of action pursued
Hydrogen-methane fuel control systems for turbojet engines
Design, development, and test of a fuel conditioning and control system utilizing liquid methane (natural gas) and liquid hydrogen fuels for operation of a J85 jet engine were performed. The experimental program evaluated the stability and response of an engine fuel control employing liquid pumping of cryogenic fuels, gasification of the fuels at supercritical pressure, and gaseous metering and control. Acceptably stable and responsive control of the engine was demonstrated throughout the sea level power range for liquid gas fuel and up to 88 percent engine speed using liquid hydrogen fuel
Space Transportation System solid rocket booster thrust vector control system
The Solid Rocket Booster, Thrust Vector Control (TVC) system was designed in accordance with the following requirements: self-contained power supply, failsafe operation, 20 flight uses after exposure to seawater landings, optimized cost, and component interchangeability. Trade studies were performed which led to the selection of a recirculating hydraulic system powered by Auxiliary Power Units (APU) which drive the hydraulic actuators and gimbal the solid rocket motor nozzle. Other approaches for the system design were studied in arriving at the recirculating hydraulic system powered by an APU. These systems must withstand the imposed environment and be usable for a minimum of 20 Space Transportation System flights with a minimum of refurbishment. The TVC system completed the required qualification and verification tests and is certified for the intended application. Substantiation data include analytical and test data
An approach to high speed ship ride quality simulation
The high speeds attained by certain advanced surface ships result in a spectrum of motion which is higher in frequency than that of conventional ships. This fact along with the inclusion of advanced ride control features in the design of these ships resulted in an increased awareness of the need for ride criteria. Such criteria can be developed using data from actual ship operations in varied sea states or from clinical laboratory experiments. A third approach is to simulate ship conditions using measured or calculated ship motion data. Recent simulations have used data derived from a math model of Surface Effect Ship (SES) motion. The model in turn is based on equations of motion which have been refined with data from scale models and SES of up to 101 600-kg (100-ton) displacement. Employment of broad band motion emphasizes the use of the simulators as a design tool to evaluate a given ship configuration in several operational situations and also serves to provide data as to the overall effect of a given motion on crew performance and physiological status
Apollo docking test device design study final report
Docking simulation system for confirming Apollo probe design and drogue docking mechanisms under simulated space condition
The Effect of Dissolved Water on the Tribological Properties of Polyalkylene Glycol and Polyolester Oils
The effect of water dissolved in polyalkylene glycol and polyolester oils on the
tribological behavior of two material contact pairs in three test environments is evaluated. The
material contact pairs are M2 tool steel against 390 aluminum and M2 tool steel against gray
cast iron. The three oils are a polyalkylene glycol (PAG) and two polyolester (PEl and PE2)
oils. The test environments are R134a, air and argon. The tests are conducted in a specially
designed high pressure tribometer which provides an accurate control of the test variables.
The results indicate that the P AG oil performed better than the esters for both material
contact pairs. The wear on the aluminum plates for the tests conducted with the P AG oil in all
three environments is greatest at the lowest moisture content levels. From the stand point of
friction and wear, it is beneficial to have a water content level of 5000 ppm or greater in the
PAG oil when the plate material is 390 aluminum. The wear on the cast iron plates, when using
a PAG oil as the lubricant showed a slight increase with water content in a R134a environment.
This trend is opposite when air is the test environment.
Both ester oils lubricated aluminum much better than the cast iron . The difference in
the amount of wear can be as high as two orders of magnitude. This is probably due to the
ability of the esters to form bidentate bonds with aluminum. Esters do not form such bonds
with iron. The plate wear is greater for the PEl tests than for the PE2 tests for both material
contact pairs. This is most likely due to the difference in the viscosity of the oils. In PE2 oil,
water does not seem to affect the friction and wear of both aluminum/steel and cast iron/steel
contacts when R134a is the test environment. On the contrary, for the aluminum/steel contacts,
the water content significantly influences wear when argon or air is the test environment. For
the cast iron/steel contacts, the wear is strongly influenced by the water content when the test is
conducted in argon, but it is not influenced by the water content when the test is conducted in
air.Air Conditioning and Refrigeration Center Project 0
A plasma arc jet facility for extraterrestrial atmospheric entry studies
Test facility for simulating thermodynamic environments of planetary atmospheric entr
Hydraulic fluid interaction servovalves Monthly technical report, 1 Feb. - 1 Mar. 1966
Hydraulic fluid interaction servovalves - valve design, torque motor specification, environment tests, and vortex valve test
Electronic/electric technology benefits study
The benefits and payoffs of advanced electronic/electric technologies were investigated for three types of aircraft. The technologies, evaluated in each of the three airplanes, included advanced flight controls, advanced secondary power, advanced avionic complements, new cockpit displays, and advanced air traffic control techniques. For the advanced flight controls, the near term considered relaxed static stability (RSS) with mechanical backup. The far term considered an advanced fly by wire system for a longitudinally unstable airplane. In the case of the secondary power systems, trades were made in two steps: in the near term, engine bleed was eliminated; in the far term bleed air, air plus hydraulics were eliminated. Using three commercial aircraft, in the 150, 350, and 700 passenger range, the technology value and pay-offs were quantified, with emphasis on the fiscal benefits. Weight reductions deriving from fuel saving and other system improvements were identified and the weight savings were cycled for their impact on TOGW (takeoff gross weight) and upon the performance of the airframes/engines. Maintenance, reliability, and logistic support were the other criteria
- …