Download or read book High Specific Impulse Thermal Arc Jet Thrustor Technology written by G. L. Cann and published by . This book was released on 1965 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thrustor was tested in a high vacuum (.0000001 torr) with lithium as a propellant, an identical thrustor was evaluated with potassium as the propellant with a wide variation of operating parameters, and improvements were made to the alkali metal feed system and the thrust measurement system. The high-vacuum tests essentially duplicated the performance of the lithium thrustor (Isp = 5000 sec, eta sub T = 53%) measured at the higher pressure of .001 torr during a 10-hour endurance test. The efficiency and maximum specific impulse of the thrustor with potassium were lower than with lithium. (Author).
Download or read book High Specific Impulse Thermal Arc Jet Thrustor Technology Part Ii Performance of Hall Arc Jets with Lithium Propellant written by Gordon L. Cann and published by . This book was released on 1967 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this program is to develop efficient electric arcjet thrustors for high specific impulse and long life. Power levels between 10 and 50 kW, specific impulse between 1500 and 6500 seconds are sought with power input-to-thrust ratios less than 190 kW/lb for durations up to 100 hours. The approach combines analytical and experimental research to investigate and develop thrustors using lithium and other alkali metals as propellants. The present approach has relied predominantly on Hall current interactions with an applied magnetic field. Thrustors of this type have been designated ALPHA (Alkali Plasma Hall Accelerator). During the second phase of the program the following advances have been made. The effects of the testing environment upon the measured performance have been investigated. Two major modifications to the design of the engine have been made: (1) the cylindrical cathode has been replaced by a buffered cathode with separate propellant injection, thereby increasing the thrust per unit current, decreasing the cathode power loss per unit current, increasing the insulator lifetime, and helping to separate the ionization and acceleration processes; (2) the region of strong magnetic field has been extended downstream by placin g a second coil on the engine, reducing magnet power requirement by a factor of almost five. Thrust balance has been improved. A new feed system has been designed to provide continuous operation for periods over 100 hours at levels around 10 mg/sec. A theory has been developed for the operation of ALPHA. Calculations based on this theory indicate that significant improvements can be made over present performance. (Author).
Download or read book High Sprcific Impulse Thermal Arc Jet Thrustor Technology Part I Performance of Hall Arc Jets with Lithium Propellant written by R. A. Moore and published by . This book was released on 1965 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this program is to develop the technology of efficient electric arc jet thrustors for high Isp and long life. It is aimed particularly at power levels up to 300 kW, Isp between 1500 and 4000 sec, and overall efficiency greater than 60% for durations of 500 hrs. The use of lithium in this Isp range requires energies per particle which are not achievable by the electrothermal arc-heating process. Thus, it is necessary to employ, in addition, electromagnetic acceleration processes. The present approach has relied predominantly on Hall current interactions with an applied magnetic field. Lithium thrustors have been tested at power levels up to 40 kW. Thrust efficiencies (neglecting power dissipated in the magnet coil) of 70% at Isp of 5000 sec, 60% at 4000 sec, 45% at 3000 sec and 30% at 2000 sec have been measured in a test chamber at pressures of the order of .01 mm Hg. Other tests demonstrated that test chamber pressures between .01 and .00001 mm Hg have little effect on performance. A 10-hr endurance test was made with a 10-kW thrustor operating at an Isp of about 5000 sec with an efficiency of 53%. (Author).
Download or read book Arc jet Thrustor for Space Propulsion written by Lewis E. Wallner and published by . This book was released on 1965 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The arc-jet thrustor represents an engine for potential space applications requiring a specific impulse in the range from 1000 to 2000 seconds. As such it was originally thought that missions for the engine would fit somewhere between those suitable for the high thrust chemical and the very low thrustion propulsion systems. The considerable effort expended to develop the arc thrustor has resulted in operation in the power range from 1 to 200 kilowatts, at specific impulse levels between 1000 and 2000 seconds, and for continuous running as long as 500 hours with overall efficiency up to 55 percent. Progress has been made on many of the early operating problems such as electrode-erosion, nozzle-cooling, and propellant-feed systems. In addition, theories have been advanced to explain, at least partially, the electric-arc operation In substance then, the thermal arc-jet thrustor is now fairly well developed. Because of several factors unrelated to impulse and efficiency levels, however, the mission application of the arc thrustor is somewhat doubtful at the present time. These factors, for the larger arc-jet thrustor, include biological shielding, hardware availability, excessive electric generator weight, and reliability, for example.
Download or read book High Specific Impulse Performance of a 100 KW Radiation Cooled Thermal Arcjet Thruster written by Thomas M. Golz and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Electric Propulsion written by Dan M. Goebel and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout most of the twentieth century, electric propulsion was considered the technology of the future. Now, the future has arrived. This important new book explains the fundamentals of electric propulsion for spacecraft and describes in detail the physics and characteristics of the two major electric thrusters in use today, ion and Hall thrusters. The authors provide an introduction to plasma physics in order to allow readers to understand the models and derivations used in determining electric thruster performance. They then go on to present detailed explanations of: Thruster principles Ion thruster plasma generators and accelerator grids Hollow cathodes Hall thrusters Ion and Hall thruster plumes Flight ion and Hall thrusters Based largely on research and development performed at the Jet Propulsion Laboratory (JPL) and complemented with scores of tables, figures, homework problems, and references, Fundamentals of Electric Propulsion: Ion and Hall Thrusters is an indispensable textbook for advanced undergraduate and graduate students who are preparing to enter the aerospace industry. It also serves as an equally valuable resource for professional engineers already at work in the field.
Download or read book Development of a High Specific 1 5 to 5 KW Thermal Arcjet written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-31 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research and development project on the experimental study of a 1.5-5 kW thermal arcjet thruster was started in 1992 at the IRS. Two radiation cooled thrusters were designed, constructed, and adapted to the test facilities, one at each end of the intended power range. These thrusters are currently subjected to an intensive test program with main emphasis on the exploration of thruster performance and thruster behavior at high specific enthalpy and thus high specific impulse. Propelled by simulated hydrazine and ammonia, the thruster's electrode configuration such as constrictor diameter and cathode gap was varied in order to investigate their influence and to optimize these parameters. In addition, test runs with pure hydrogen were performed for both thrusters. Riehle, M. and Glocker, B. and Auweter-Kurtz, M. and Kurtz, H. NASA-CR-193133, NAS 1.26:193133, IRS-93-P7 NAGW-1736...
Download or read book Arcjet Thruster Research and Technology written by and published by . This book was released on 1988 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Note written by and published by . This book was released on 1970 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by Defense Documentation Center (U.S.) and published by . This book was released on 1967 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Arcjet Thruster Research and Technology Phase 1 written by and published by . This book was released on 1987 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Arcjet Thruster Research and Technology Phase 1 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-25 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The principal objective of this two phase program is to conduct the development research required to make the low power arcjet a flight ready technology. Many important results were obtained during Phase 1 to move closer to this objective. Fundamental analyses were performed of the arcjet nozzle, the gas kinetic reaction effects, the thermal environment, and the arc stabilizing vortex. These aided the conceptual understanding of the arcjet and guided design work. A hydrazine (N2H4) arcjet was designed that combined a flight qualified catalyst bed with a modular arcjet. Extensive testing was performed which demonstrated the feasibility of using this propellant in an arcjet for the first time. Startup techniques were developed, stability maintained, material compatibility tests conducted, and performance mapping tests performed. Specific impulse values from 400 to 730 seconds were produced with a non-optimized design. These levels are higher than were originally thought possible and proved that extremely high enthalpy values can be obtained with constricted arc technology. Erosion rate data are promising for lifetime extensions to meet flight application requirements. Power control unit (PCU) development was started with the design and fabrication of a laboratory high switching frequency supply. Valuable data were obtained on PCU operation and on the interaction with the dynamic arc. Phase 2 efforts presently underway are resolving key issues for multi-hundred hour lifetimes, are continuing to investigate arcjet/PCU interactions, and will demonstrate duty cycle N2H4 arcjet/PCU operation in a simulated flight mode for lifetimes consistent with initial applications. Unspecified Center NASA-CR-182106, NAS 1.26:182106 NAS3-24631
Download or read book Axisymmetric Hall arc Jet Wind Tunnel Driver Study written by Robert Richter and published by . This book was released on 1967 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DEVELOPMENT OF A THERMAL ARC ENGINE written by PLASMADYNE SANTA ANA CA. and published by . This book was released on 1964 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a 30 KW electrothermal (arc-jet) engine for space propulsion is described. An experimental 30 KW DC thruster was redesigned to increase life and decrease propellant leakage while maintaining the high level of performance (I sub sp = 1000 sec.; eta> or = 50%) obtained during that research program. Concurrently, other components of the engine, including a hydrogen propellant storage and feed unit, starter and engine controls, and mounting structure were designed, procured or fabricated, and assembled as a demonstration engine. The major accomplishments during this program were (1) operation of a thruster at a nominal specific impulse of 1000 seconds for twenty-five hours with negligible erosion; (2) development of a cryogenic hydrogen propellant storage and feed unit and engine controls suitable for unattended engine stand-by and operation; and (3) demonstration of a high level of thruster performance (efficiency values above 50 percent at a specific impulse of 1000 seconds) in a flight-type thruster. This type of engine is now ready for an advanced development phase, which is necessary to insure the reliability of such a propulsion device during prospective space missions. (Author).
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Jet Technology written by P. R. Dennis and published by . This book was released on 1965 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance and Diagnostics of a Water cooled Magnetoplasmadynamic Arc Thruster written by D. J. Connolly and published by . This book was released on 1970 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
