Search NASA⌕ Search

SEARCH · Search NASA

Results for “METALLIZED PROPELLANTS”

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.

At least 91 records · Page 5

Aerodynamic Characteristics of Twenty-Four Airfoils at High Speeds

The aerodynamic characteristics of 24 airfoils are given for speeds of 0.5, 0.65, 0.8, 0.95, and 1.08 times the speed of sound, as measured in an open-jet air stream 2 inches in diameter, using models of 1-inch chord. The 24 airfoils belong to four general groups. The first is the standard R. A. F. family in general use by the Army and Navy for propeller design, the members of the family differing only in thickness. This family is represented by nine members ranging in thickness from 0.04 to 0.20 inch. The second group consists of five members of the Clark Y family, the members of the family again differing only in thickness. The third group, comprising six members, is a second R. A. F. Family in which the position of the maximum ordinate is varied. Combined with two members of the first R.A.F. family, this group represents a variation of maximum ordinate position from 30 to 60 percent of the chord in two camber ratios, 0.08 and 0.16. The fourth group consists of three geometrical forms, a flat plate, a wedge, and a segment of a right circular cylinder. In addition one section used in the reed metal propeller was included. These measurements form a part of a general program outlined at a Conference on Propeller Research organized by the National Advisory Committee for Aeronautics and the work was carried out with the financial assistance of the committee (author)

Brigg, L J↗

The MPD thruster program at JPL

The main topics covered include: (1) the Space Exploration Initiative (SEI) context; (2) critical issues of MPD Thruster design; and (3) the Magnetoplasmadynamic (MPD) Thruster Program at JPL. Under the section on the SEI context the nuclear electric propulsion system and some electric thruster options are addressed. The critical issues of MPD Thruster development deal with the requirements, status, and approach taken. The following areas are covered with respect to the MPD Thruster Program at JPL: (1) the radiation-cooled MPD thruster; (2) the High-Current Cathode Test Facility; (3) thruster component thermal modeling; and (4) alkali metal propellant studies.

Barnett, John↗

Liquid-Metal-Fed Pulsed Electromagnetic Thrusters For In-Space Propulsion

We describe three pulsed electromagnetic thruster concepts, which span four orders of magnitude in power processing capability (100 W to >100 kW), for in-space propulsion applications. The primary motivation for using a pulsed system is to is to enable high (instantaneous) power operation, which provides high acceleration efficiency, while using considerably less (continuous) power from the spacecraft power system. Unfortunately, conventional pulsed thrusters require failure-prone electrical switches and gas-puff valves. The series of thrusters described here directly address this problem, through the use of liquid metal propellant, by either eliminating both components or providing less taxing operational requirements, thus yielding a path toward both efficient and reliable pulsed electromagnetic thrusters. The emphasis of this paper is to conceptually describe each of the thruster concepts; however, initial test results with gallium propellant in one thruster geometry are presented. These tests reveal that a greater understanding of gallium material compatibility, contamination, and wetting behavior will be necessary before a completely functional thruster can be developed. Initial experimental results aimed at providing insight into these issues are presented.

Markusic, T. E.↗

Mechanical Data for Use in Damage Tolerance Analyses

This report describes the results of a research program to determine the damage tolerance properties of metallic propeller materials. Three alloys were selected for investigation: 2025-T6 Aluminum, D6AC Steel and 4340 Steel. Mechanical response, fatigue (S-N) and fatigue crack growth rate data are presented for all of the alloys. The main conclusions that can be drawn from this study are as follows. The damage tolerant design of a propeller system will require a complete understanding of the fatigue crack growth threshold. There exists no experimental procedure to reliably develop the fatigue crack growth threshold data that is needed for damage tolerant design methods. Significant research will be required to fully understand the fatigue crack growth threshold. The development of alternative precracking methods, evaluating the effect of specimen configuration and attempting to identify micromechanical issues are simply the first steps to understanding the mechanics of the threshold.

Forth, Scott C.↗

Unibody Composite Pressurized Structure

An integrated, generic unibody composite pressurized structure (UCPS) combined with a positive expulsion device (PED), consisting of an elastomeric bladder for monopropellant hydrazine, has been quasi-standardized for spacecraft use. The combination functions as an all-composite, non-metallic, propellant tank with bladder. The integrated UCPS combines several previous innovations - specifically, the linerless, all-composite cryogenic tank technology; all-composite boss; resin formulation; and integrated stringer system. The innovation combines the UCPS with an integrated propellant management device (PMD), the PED or bladder, to create an entirely unique system for in-space use. The UCPS is a pressure vessel that incorporates skirts, stringers, and other structures so that it is both an in-space hydrazine tank, and also a structural support system for a spacecraft in a single, all-composite unit. This innovation builds on the progress in the development of a previous SBIR (Small Business Innovation Research) Phase I with Glenn Research Center and an SBIR III with Johnson Space Center that included the fabrication of two 42-in. (≈107-cm) diameter all-composite cryogenic (LOX and liquid methane) UCPS test tanks for a lunar lander. This Phase II provides hydra zine compatibility testing of the elastomeric bladder, a see-through PED to validate the expulsion process and model, and a complete UCPS-based PED with stringers and skirts that will be used to conduct initial qualification and expulsion tests. This extends the UCPS technology to include hydrazine-based, in-space pro - pulsion applications and can also be used for electric propulsion. This innovation creates a system that, in comparison to the traditional approach, is lower in weight, cost, volume, and production time; is stronger; and is capable of much higher pressures. It also has fewer failure modes, and is applicable to both chemical and electric propulsion systems.

Rufer, Markus↗

Unibody Composite Pressurized Structure (UCPS) for In-Space Propulsion

Microcosm, Inc., in conjunction with the Scorpius Space Launch Company, is developing a UCPS (Unibody Composite Pressurized Structure )for in-space propulsion. This innovative approach constitutes a clean break from traditional spacecraft design by combining what were traditionally separate primary and secondary support structures and metal propellant tanks into a single unit.

Rufer, Markus↗

Flight Metal Plasma Thruster (MPT) Development, Qualification, and Thrust Measurement Campaign

A torsional thrust stand, calibrated for impulse bits in the range of 0.1mNs -0.5 mNs, was used to measure impulse bits during two campaigns at the NASA/GRC VF-3 Vacuum test Facility. Metal Plasma Thrusters (MPTs) with targets of Molybdenum, Copper and Stainless Steel (as used in upper stages of launch vehicles that are abandoned in LEO) were tested. This paper describes data from Mo targets (called pucks). The Cu and ss data will be presented elsewhere. Model predictions (based on a simple circuit model and published plasma parameters) were validated by data from the calibrated torsional thrust stand. The Metal Plasma Thruster uses solid metal propellant, hence requires no liquids, gases, flow valves or flow controls and has no moving parts. Total impulse ~5000Ns/U provides orbit raising and drag compensation capability.

Electric Propulsion↗

Flight MPT Development, Qualification and Thrust Measurement Campaign

A torsional thrust stand, calibrated for impulse bits in the range of 0.1mNs -0.5 mNs, was used to measure impulse bits during two campaigns at the NASA/GRC VF-3 Vacuum test Facility. Metal Plasma Thrusters (MPTs) with targets of Molybdenum, Copper and Stainless Steel (as used in upper stages of launch vehicles that are abandoned in LEO) were tested. This paper describes data from Mo targets (called pucks). The Cu and ss data will be presented elsewhere. Model predictions (based on a simple circuit model and published plasma parameters) were validated by data from the calibrated torsional thrust stand. The Metal Plasma Thruster uses solid metal propellant, hence requires no liquids, gases, flow valves or flow controls and has no moving parts. Total impulse ~5000Ns/U provides orbit raising and drag compensation capability.

Electric Propulsion↗

Advanced chemical propulsion at NASA Lewis: Metallized and high energy density propellants

Two of the programs at the NASA Lewis Research Center investigating advanced systems for future space missions are the Metallized Propellant Program and the Advanced Concepts Program. Each program includes both experimental and theoretical studies of future propellants and the associated vehicle impacts and significant payload benefits for many types of space transportation. These programs are described.

Palaszewski, Bryan A.↗

Effect of silicone oil on nozzle heat transfer in solid propellant rockets

The feasibility of reducing heat transfer rates to inert nozzle walls in solid rockets by addition of silicone oil as a propellant ingredient is explored experimentally. A metallized control propellant and its counterpart with 1% silicone oil are fired in a 2 1/2-in. diameter end burning all-metal burner. Pressure-time histories are obtained; temperature-time data at the nozzle throat are obtained in some of the runs. The heat loss by the product gases to the cold inert walls of the nozzle lower the temperature of the gases leading to the condensation of aluminum oxide on the walls. This condensation is used as an index of the heat transfer rate to the nozzle. On a statistical basis it is found that the silicone propellant gives practically no condensation in 70% of the firings contrasted with 21% for its counterpart with no silicone oil in it. The gas temperature at the nozzle throat is experimentally seen to be generally higher with the silicone propellant than with its counterpart; this higher temperature is consistent with a preliminary analysis that is used here to relate the nozzle surface temperature to the heat transfer from the product gases.

Ramohalli, K.↗

Qualification of a Pulsed, Millinewton Class Metal Plasma Thruster for Broad Mission Applications

In the field of low power (<100W) electric propulsion, all thruster options demand significant trade-offs between operating parameters, reliability and scalable cost. With many systems on the market there are concerns with reliability, the need for extra considerations such as electron neutralizers for pure ion plumes, and the cost or craft compatibility of propellants. The Metal Plasma Thruster (MPT) is a new type of electric propulsion technology intended for low power applications. The system imparts momentum using inert, solid metal pucks as a propellant by using pulsed power to convert the metal into high velocity (~17km/s for Mo) jets of quasi-neutral plasma. The MPT technology does not require gas or liquid propellants, neutralizers, standby heaters, high voltage electronics, high electric or magnetic fields to operate. This comparatively simple pulsed operation is amenable to closed loop control, which provides for fine thrust control and S/C directed impulse on demand. Furthermore, the technology can use any metal as propellant, opening up unique opportunities for In-Situ Resource Utilization (ISRU) as well as customizability of performance for meeting specific mission needs. This paper describes implementation and direct measurement of this closed loop control mode as well as impulse measurement of multiple metals consistent with the aim of ISRU at NASA Glenn Research Center (GRC).

Electric Propulsion↗

Qualification of a Pulsed, Millinewton Class Metal Plasma Thruster for Broad Mission Applications

In the field of low power (<100W) electric propulsion, all thruster options demand significant trade-offs between operating parameters, reliability and scalable cost. With many systems on the market there are concerns with reliability, the need for extra considerations such as electron neutralizers for pure ion plumes, and the cost or craft compatibility of propellants. The Metal Plasma Thruster (MPT) is a new type of electric propulsion technology intended for low power applications. The system imparts momentum using inert, solid metal pucks as a propellant by using pulsed power to convert the metal into high velocity (~17km/s for Mo) jets of quasi-neutral plasma. The MPT technology does not require gas or liquid propellants, neutralizers, standby heaters, high voltage electronics, high electric or magnetic fields to operate. This comparatively simple pulsed operation is amenable to closed loop control, which provides for fine thrust control and S/C directed impulse on demand. Furthermore, the technology can use any metal as propellant, opening up unique opportunities for In-Situ Resource Utilization (ISRU) as well as customizability of performance for meeting specific mission needs. This paper describes implementation and direct measurement of this closed loop control mode as well as impulse measurement of multiple metals consistent with the aim of ISRU at NASA Glenn Research Center (GRC).

Electric Propulsion↗