Search NASA⌕ Search

SEARCH · Search NASA

Results for “Propellant Transfer”

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 775 records · Page 43

Measurements of Aerodynamic Heat Transfer and Boundary-Layer Transition on a 10 deg Cone in Free Flight at Supersonic Mach Numbers up to 5.9

Measurements of aerodynamic heat transfer have been made at six stations on the 40-inch-long 10 deg. total-angle conical nose of a rocket- propelled model which was flight tested at Mach numbers up to 5.9. are presented for a range of local Mach number just outside the bound- ary layer on the cone from 1.57 to 5.50, and a range of local Reynolds number from 6.6 x 10(exp 6) to 55.2 x 10(exp 6) based on length from the nose tip.

Rumsey, Charles B.↗

Low Gravity Issues of Deep Space Refueling

This paper discusses the technologies required to develop deep space refueling of cryogenic propellants and low cost flight experiments to develop them. Key technologies include long term storage, pressure control, mass gauging, liquid acquisition, and fluid transfer. Prior flight experiments used to mature technologies are discussed. A plan is presented to systematically study the deep space refueling problem and devise low-cost experiments to further mature technologies and prepare for full scale flight demonstrations.

Chato, David J.↗

Vacuum Deployment and Testing of a 4-Quadrant Scalable Inflatable Solar Sail System

Solar sails reflect photons streaming from the sun and transfer momentum to the sail. The thrust, though small, is continuous and acts for the life of the mission without the need for propellant. Recent advances in materials and ultra-low mass gossamer structures have enabled a host of useful missions utilizing solar sail propulsion. The team of L'Garde, Jet Propulsion Laboratories, Ball Aerospace, and Langley Research Center, under the direction of the NASA In-Space Propulsion office, has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. The baseline design currently in development and testing was optimized around the 1 AU solar sentinel mission. Featuring inflatably deployed sub-T(sub g), rigidized beam components, the 10,000 sq m sail and support structure weighs only 47.5 kg, including margin, yielding an areal density of 4.8 g/sq m. Striped sail architecture, net/membrane sail design, and L'Garde's conical boom deployment technique allows scalability without high mass penalties. This same structural concept can be scaled to meet and exceed the requirements of a number of other useful NASA missions. This paper discusses the interim accomplishments of phase 3 of a 3-phase NASA program to advance the technology readiness level (TRL) of the solar sail system from 3 toward a technology readiness level of 6 in 2005. Under earlier phases of the program many test articles have been fabricated and tested successfully. Most notably an unprecedented 4-quadrant 10 m solar sail ground test article was fabricated, subjected to launch environment tests, and was successfully deployed under simulated space conditions at NASA Plum Brook s 30m vacuum facility. Phase 2 of the program has seen much development and testing of this design validating assumptions, mass estimates, and predicted mission scalability. Under Phase 3 a much larger 20 m square test article including subscale vane has been fabricated and tested. A 20 m system ambient deployment has been successfully conducted after enduring Delta-2 launch environment testing. The program will culminate in a vacuum deployment of a 20 m subscale test article at the NASA Glenn s Plum Brook 30 m vacuum test facility to bring the TRL level as close to 6 as possible in 1 g. This focused program will pave the way for a flight experiment of this highly efficient space propulsion technology.

Lichodziejewski, David↗

Analysis of Integrated Spacecraft Performance Using A Rotating Detonation Rocket Engine

For spacecraft with especially stringent mass fraction constraints, the use of a rotating detonation rocket engine (RDRE) may yield potentially significant system mass savings. The pressure gain combustion inherent to RDREs provides higher thrust than traditional rocket engines for a given supply pressure and throat area. This opens multiple avenues for reducing system mass via higher specific impulse, reduced gravity losses, and reduced feed pressures. To highlight the potentially weight-saving characteristics of RDRE systems, the integrated performance of representative spacecraft designs using either a conventional rocket engine or an RDRE was assessed. This paper details the assumptions, methods, and results of this trade study. Two representative spacecraft were assessed. The first is a Liquid Mars Ascent Vehicle (MAV). This spacecraft was designed by NASA in 2011 for the Mars Sample Return Campaign but was not selected for flight due in part to it exceeding the mass requirements by 119 lbm. The second is MIURA-1, a kerolox sounding rocket developed by Payload Aerospace S.L.. The Liquid MAV assessment showed that an RDRE powered design met the mass requirements with a total vehicle mass 46 lbm below the limit. The MIURA-1 assessment showed that wall heat transfer and regenerative cooling are significant challenges for kerolox RDREs, but these challenges may be mitigated by reducing mixture ratio and using both propellants to cool the chamber. The assessment showed that an RDRE powered sounding rocket could achieve 12% more microgravity time than a conventional sounding rocket with the same payload and total vehicle mass. Alternately, if the payload mass and target apogee are held constant, then an RDRE powered sounding rocket can be 8% shorter and 11% lighter than a conventional sounding rocket. These results suggest that the advent of RDREs for in-space propulsion may unlock new missions for which conventional propulsion is not feasible.

Rotating Detonation Rocket Engine↗

Analysis of Integrated Spacecraft Performance Using Rotating Detonation Rocket Engine

For spacecraft with especially stringent mass fraction constraints, the use of a rotating detonation rocket engine (RDRE) may yield potentially significant system mass savings. The pressure gain combustion inherent to RDREs provides higher thrust than traditional rocket engines for a given supply pressure and throat area. This opens multiple avenues for reducing system mass via higher specific impulse, reduced gravity losses, and reduced feed pressures. To highlight the potentially weight-saving characteristics of RDRE systems, the integrated performance of representative spacecraft designs using either a conventional rocket engine or an RDRE was assessed. This paper details the assumptions, methods, and results of this trade study. Two representative spacecraft were assessed. The first is a Liquid Mars Ascent Vehicle (MAV). This spacecraft was designed by NASA in 2011 for the Mars Sample Return Campaign but was not selected for flight due in part to it exceeding the mass requirements by 119 lbm. The second is MIURA-1, a kerolox sounding rocket developed by Payload Aerospace S.L.. The Liquid MAV assessment showed that an RDRE powered design met the mass requirements with a total vehicle mass 46 lbm below the limit. The MIURA-1 assessment showed that wall heat transfer and regenerative cooling are significant challenges for kerolox RDREs, but these challenges may be mitigated by reducing mixture ratio and using both propellants to cool the chamber. The assessment showed that an RDRE powered sounding rocket could achieve 12% more microgravity time than a conventional sounding rocket with the same payload and total vehicle mass. Alternately, if the payload mass and target apogee are held constant, then an RDRE powered sounding rocket can be 8% short and 11% lighter than a conventional sounding rocket. These results suggest that the advent of RDREs for in-space propulsion may unlock new missions for which conventional propulsion is not feasible.

Rotating Detonation Rocket Engine↗

Dynamic condensation model of rolling droplets for high-performance heat transfer

Condensation is a critical process during vapor-liquid phase change in relation to heat transfer. To achieve a high heat transfer coefficient, the classical model for dropwise condensation requires a low contact angle and low contact angle hysteresis, failing to align with experimental observations on a hydrophobic and slippery quasi-liquid surface (QLS). Here, we report a dynamic condensation model that incorporates high-frequency condensate removal by emphasizing the role of timescale during droplet growth and shedding. Our model agrees well with the experimental result that a surface with high contact angle and low contact angle hysteresis promotes condensation, particularly during rolling-propelled condensate removal. Particle image velocimetry reveals that rolling droplets on a hydrophobic QLS exhibit 4-fold higher shedding speeds than the sliding droplets on a hydrophilic QLS, leading to significant heat transfer enhancement. This work deepens our theoretical understanding of condensation heat transfer and provides advanced physics-informed design rationales for water and energy systems.

42 ENGINEERING↗

A reexamination of the laser supported combustion wave

Kantrowitz (1972) and Minovitch (1972) have proposed the use of laser sustained plasmas as a means to heat a rocket propellant. Recent studies of laser-powered propulsion have been directed toward the application of high-specific-impulse space propulsion systems for orbital transfer missions. Analyses of rocket performance relied heavily on the concept of the laser-supported combustion (LSC) wave. Raizer (1971) first drew the analogy between laser-sustained plasmas and combustion waves in an analysis. The Raizer model was later applied to hydrogen by Kemp and Root (1979). In connection with certain problems arising with the approach considered by Kemp and Root, the present investigation is concerned with a reexamination of the Raizer model. Attention is given to a numerical approach for the entire LSC wave in hydrogen, taking into account the incorporation of the proper boundary conditions far downstream of the wave.

Keefer, D.↗

Megawatt level electric propulsion perspectives

For long range space missions, deliverable payload fraction is an inverse exponential function of the propellant exhaust velocity or specific impulse of the propulsion system. The exhaust velocity of chemical systems are limited by their combustion chemistry and heat transfer to a few km/s. Nuclear rockets may achieve double this range, but are still heat transfer limited and ponderous to develop. Various electric propulsion systems can achieve exhaust velocities in the 10 km/s range, at considerably lower thrust densities, but require an external electrical power source. A general overview is provided of the currently available electric propulsion systems from the perspective of their characteristics as a terminal load for space nuclear systems. A summary of the available electric propulsion options is shown and generally characterized in the power vs. exhaust velocity plot. There are 3 general classes of electric thruster devices: neutral gas heaters, plasma devices, and space charge limited electrostatic or ion thrusters.

Jahn, Robert G.↗

Performance Capability of Single-Cavity Vortex Gaseous Nuclear Rockets

An analysis was made to determine the maximum powerplant thrust-to-weight ratio possible with a single-cavity vortex gaseous reactor in which all the hydrogen propellant must diffuse through a fuel-rich region. An assumed radial temperature profile was used to represent conduction, convection, and radiation heat-transfer effects. The effect of hydrogen property changes due to dissociation and ionization was taken into account in a hydrodynamic computer program. It is shown that, even for extremely optimistic assumptions of reactor criticality and operating conditions, such a system is limited to reactor thrust-to-weight ratios of about 1.2 x 10(exp -3) for laminar flow. For turbulent flow, the maximum thrust-to-weight ratio is less than 10(exp -3). These low thrusts result from the fact that the hydrogen flow rate is limited by the diffusion process. The performance of a gas-core system with a specific impulse of 3000 seconds and a powerplant thrust-to-weight ratio of 10(exp -2) is shown to be equivalent to that of a 1000-second advanced solid-core system. It is therefore concluded that a single-cavity vortex gaseous reactor in which all the hydrogen must diffuse through the nuclear fuel is a low-thrust device and offers no improvement over a solid-core nuclear-rocket engine. To achieve higher thrust, additional hydrogen flow must be introduced in such a manner that it will by-pass the nuclear fuel. Obviously, such flow must be heated by thermal radiation. An illustrative model of a single-cavity vortex system employing supplementary flow of hydrogen through the core region is briefly examined. Such a system appears capable of thrust-to-weight ratios of approximately 1 to 10. For a high-impulse engine, this capability would be a considerable improvement over solid-core performance. Limits imposed by thermal radiation heat transfer to cavity walls are acknowledged but not evaluated. Alternate vortex concepts that employ many parallel vortices to achieve higher hydrogen flow rates offer the possibility of sufficiently high thrust-to-weight ratios, if they are not limited by short thermal-radiation path lengths.

Ragsdale, Robert G.↗

High-Area-Ratio Rocket Nozzle at High Combustion Chamber Pressure: Experimental and Analytical Validation

Experimental data were obtained on an optimally contoured nozzle with an area ratio of 1025:1 and on a truncated version of this nozzle with an area ratio of 440:1. The nozzles were tested with gaseous hydrogen and liquid oxygen propellants at combustion chamber pressures of 1800 to 2400 psia and mixture ratios of 3.89 to 6.15. This report compares the experimental performance, heat transfer, and boundary layer total pressure measurements with theoretical predictions of the current Joint Army, Navy, NASA, Air Force (JANNAF) developed methodology. This methodology makes use of the Two-Dimensional Kinetics (TDK) nozzle performance code. Comparisons of the TDK-predicted performance to experimentally attained thrust performance indicated that both the vacuum thrust coefficient and the vacuum specific impulse values were approximately 2.0-percent higher than the turbulent prediction for the 1025:1 configurations, and approximately 0.25-percent higher than the turbulent prediction for the 440:1 configuration. Nozzle wall temperatures were measured on the outside of a thin-walled heat sink nozzle during the test fittings. Nozzle heat fluxes were calculated front the time histories of these temperatures and compared with predictions made with the TDK code. The heat flux values were overpredicted for all cases. The results range from nearly 100 percent at an area ratio of 50 to only approximately 3 percent at an area ratio of 975. Values of the integral of the heat flux as a function of nozzle surface area were also calculated. Comparisons of the experiment with analyses of the heat flux and the heat rate per axial length also show that the experimental values were lower than the predicted value. Three boundary layer rakes mounted on the nozzle exit were used for boundary layer measurements. This arrangement allowed total pressure measurements to be obtained at 14 different distances from the nozzle wall. A comparison of boundary layer total pressure profiles and analytical predictions show good agreement for the first 0.5 in. from the nozzle wall; but the further into the core flow that measurements were taken, the more that TDK overpredicted the boundary layer thickness.

Jankovsky, Robert S.↗

Modular Growth NTR Space Transportation System for Future NASA Human Lunar, NEA and Mars Exploration Missions

The nuclear thermal rocket (NTR) is a proven, high thrust propulsion technology that has twice the specific impulse (I(sub sp) approx.900 s) of today's best chemical rockets. During the Rover and NERVA (Nuclear Engine for Rocket Vehicle Applications) programs, twenty rocket reactors were designed, built and ground tested. These tests demonstrated: (1) a wide range of thrust; (2) high temperature carbide-based nuclear fuel; (3) sustained engine operation; (4) accumulated lifetime; and (5) restart capability - everything required for affordable human missions beyond LEO. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, the NTR was selected as the preferred propulsion option because of its proven technology, higher performance, lower IMLEO, versatile vehicle design, and growth potential. Furthermore, the NTR requires no large technology scale-ups since the smallest engine tested during the Rover program - the 25 klb(sub f) "Pewee" engine is sufficient for human Mars missions when used in a clustered engine configuration. The "Copernicus" crewed Mars transfer vehicle developed for DRA 5.0 was an expendable design sized for fast-conjunction, long surface stay Mars missions. It therefore has significant propellant capacity allowing a reusable "1-year" round trip human mission to a large, high energy near Earth asteroid (NEA) like Apophis in 2028. Using a "split mission" approach, Copernicus and its two key elements - a common propulsion stage and integrated "saddle truss" and LH2 drop tank assembly - configured as an Earth Return Vehicle / propellant tanker, can also support a short round trip (approx.18 month) / short orbital stay (60 days) Mars reconnaissance mission in the early 2030's before a landing is attempted. The same short stay orbital mission can be performed with an "all-up" vehicle by adding an "in-line" LH2 tank to Copernicus to supply the extra propellant needed for this higher energy, opposition-class mission. To transition to a reusable Mars architecture, Copernicus' saddle truss / drop tank assembly is replaced by an in-line tank and "star truss" assembly with paired modular drop tanks to further increase the vehicle's propellant capacity. Shorter "1-way" transit time fast-conjunction Mars missions are another possibility using this vehicle configuration but, as with reusability, increased launch mass is required. "Scaled down" versions of Copernicus (sized to a SLS lift capability of approx.70 t - 100 t) can be developed initially allowing reusable lunar cargo delivery and crewed landing missions, easy NEA missions (e.g., 2000 SG344 also in 2028) or an expendable mission to Apophis. Mission scenario descriptions, key vehicle features and operational characteristics are provided along with a brief discussion of NASA's current activities and its "pre-decisional" plans for future NTR development.

Borowski, Stanley K.↗

Project Genesis: Mars in situ propellant technology demonstrator mission

Project Genesis is a low cost, near-term, unmanned Mars mission, whose primary purpose is to demonstrate in situ resource utilization (ISRU) technology. The essence of the mission is to use indigenously produced fuel and oxidizer to propel a ballistic hopper. The Mars Landing Vehicle/Hopper (MLVH) has an Earth launch mass of 625 kg and is launched aboard a Delta 117925 launch vehicle into a conjunction class transfer orbit to Mars. Upon reaching its target, the vehicle performs an aerocapture maneuver and enters an elliptical orbit about Mars. Equipped with a ground penetrating radar, the MLVH searches for subsurface water ice deposits while in orbit for several weeks. A deorbit burn is then performed to bring the MLVH into the Martian atmosphere for landing. Following aerobraking and parachute deployment, the vehicle retrofires to a soft landing on Mars. Once on the surface, the MLVH begins to acquire scientific data and to manufacture methane and oxygen via the Sabatier process. This results in a fuel-rich O2/CH4 mass ratio of 2, which yields a sufficiently high specific impulse (335 sec) that no additional oxygen need be manufactured, thus greatly simplifying the design of the propellant production plant. During a period of 153 days the MLVH produces and stores enough fuel and oxidizer to make a 30 km ballistic hop to a different site of scientific interest. At this new location the MLVH resumes collecting surface and atmospheric data with the onboard instrumentation. Thus, the MLVH is able to provide a wealth of scientific data which would otherwise require two separate missions or separate vehicles, while proving a new and valuable technology that will facilitate future unmanned and manned exploration of Mars. Total mission cost, including the Delta launch vehicle, is estimated to be $200 million.

Acosta, Francisco Garcia↗

Low thrust chemical propulsion for orbit transfer of large space structures

For transporting Large Space Structures (LSS) from Low Earth Orbit (LEO) to Geosynchronous Equatorial Orbit (GEO), a variety of low thrust engine cycles have been evaluated for oxygen/hydrogen and oxygen/hydrocarbon propellants. The engine cycles included conventional propellant turbine drives (gas generator, expander, and staged-combustion cycles), turboalternator/electric motor pump drive, and fuel-cell/electric motor pump drive, as well as pressure-fed engines. The thrust chamber cooling limits and the engine cycle limits were established for a range of thrust levels. The candidate engine cycles were analyzed, screened, rated, and two engine cycle/configurations were selected for preliminary engine design. Preliminary engine designs for these two engines were formulated and engine design layouts prepared and parametric engine data generated.

Shoji, J. M.↗

Prediction of the ullage gas thermal stratification in a NASP vehicle propellant tank experimental simulation using FLOW-3D

As part of the National Aero-Space Plane (NASP) project, the multi-dimensional effects of gravitational force, initial tank pressure, initial ullage temperature, and heat transfer rate on the 2-D temperature profiles were studied. FLOW-3D, a commercial finite difference fluid flow model, was used for the evaluation. These effects were examined on the basis of previous liquid hydrogen experimental data with gaseous hydrogen pressurant. FLOW-3D results were compared against an existing 1-D model. In addition, the effects of mesh size and convergence criteria on the analytical results were investigated. Suggestions for future modifications and uses of FLOW-3D for modeling of a NASP tank are also presented.

Hardy, Terry L.↗

High performance N2O4/amine elements blowapart

Hypergolic earth-storable N2O4/Amine propellants are used for a wide range of liquid propulsion system applications. These propellants are highly reactive and can experience reactive stream separation (RSS, i.e., blowapart) which can inhibit intraelement mixing, hence reducing the overall spray mixture ratio and mass distribution, which can result in altered combustion efficiency, gas-side heat transfer coefficient, and stability. An experimental and analytical program was conducted to develop an understanding of the mechanisms controlling RSS. The program and product was development of design criteria for coping with RSS to allow the design of high performing, stable injectors. RSS mechanisms were identified using high speed color photography to observe reactive stream mixing of single element injectors tested with N2O4/MMH, N2O4/A-50, and N2O4/N2H4 propellants. The parametric characterization included modeling of the Space Shuttle Orbital Maneuvering System and Reaction Control System engine injectors.

Source record↗

Nodal Numerical Modeling of Submerged Helium Injection in a Cryogenic Propellant Tank

Subcooling of cryogenic propellant by helium injection is one of the most effective methods for suppressing bulk boiling and keeping subcooled propellant conditions for pre-launch, launch, and post-launch pressurization applications. For tank pressurization, submerged helium injection can substantially reduce helium consumption by infusing gaseous propellant into the tank ullage. This paper presents a mathematical model of the helium bubbling process in liquid oxygen to estimate the amount of oxygen vapor absorbed by the rising helium bubbles and the amount of subcooling of liquid oxygen due to evaporative heat and mass transfer. This mathematical model was incorporated in a simulation model of tank pressurization built with Generalized Fluid System Simulation Program (GFSSP), a general-purpose flow network code developed at NASA/Marshall Space Flight Center. The numerical predictions of subcooling have been compared with the experimental data of Cho et al. which investigated the propellant subcooling effect as a function of system pressure, helium injection temperature, and flowrate for a non-drained submerged injection system. The numerical predictions of helium consumption have been compared with the test data from a NASA Centaur test vehicle which included both direct and submerged injection with draining of propellants. The numerical model developed with GFSSP has been validated against two sets of experimental data and has been shown to predict both propellant subcooling and helium consumption to within 30% in most cases. The test data used for the model validation were taken in 1-g, but the mass diffusion model was developed to be applied in both 1-g and micro-g environments.

Cryogenics↗

Microwave Driven Magnetic Plasma Accelerator Studies (CYCLOPS)

A microwave-driven cyclotron resonance plasma acceleration device was investigated using argon, krypton, xenon, and mercury as propellants. Limited ranges of propellant flow rate, input power, and magnetic field strength were used. Over-all efficiencies (including the 65% efficiency of the input polarizer) less than 10% were obtained for specific impulse values between 500 and 1500 sec. Power transfer efficiencies, however, approached 100% of the input power available in the right-hand component of the incident circularly polarized radiation. Beam diagnostics using Langmuir probes, cold gas mapping, r-f mapping and ion energy analyses were performed in conjunction with an engine operating in a pulsed mode. Measurements of transverse electron energies at the position of cyclotron resonant absorption yielded energy values more than an order of magnitude lower than anticipated. The measured electron energies were, however, consistent with the low values of average ion energy measured by retarding potential techniques. The low values of average ion energy were also consistent with the measured thrust values. It is hypothesized that ionization and radiation limit the electron kinetic energy to low-values thus limiting the energy which is finally transferred to the ion. Thermalization by electron-electron collision was also identified as an additional loss mechanism. The use of light alkali metals, which have relatively few low lying energy levels to excite, with the input power to mass ratio selected so as to limit the electron energies to less than the second ionization potential, is suggested. It is concluded, however, that the over-all efficiency for such propellants would be less than 40 per cent.

CYCLOPS PLASMA ACCELERATOR↗

SmallSat missions enabled by paired low-thrust hybrid rocket and low-power long-life Hall thruster

The capabilities of a SmallSat-class spacecraft targeting the outer solar system and using a combined chemical and electric propulsion system are explored. The development of compact hybrid rockets has enabled high-thrust engines to be packaged tightly enough to fit on cubesat and SmallSat spacecraft. These hybrid rockets provide 10’s-100 N of thrust depending on the propellant load & >300 s of specific impulse and have been demonstrated in both ambient and vacuum environments. Advancements in low-power long-life Hall thruster technologies have provided the potential for significantly greater propellant throughputs, enabling their use as a primary propulsion element on interplanetary spacecraft. In a recent characterization test campaign, the MaSMi-DM Hall thruster demonstrated power throttling from 150 – 1000 W with >1500 s of specific impulse available at >500 W and >40% total thrust efficiency available at >300 W; peak values of 1940 s and 53% were observed. A notional low-mass spacecraft employing a combined hybrid rocket and low-power electric propulsion system was designed and used for mission concept analysis targeting the outer solar system. Using an imposed wet mass limit of 400 kg, mission trajectories to Saturn and Uranus were generated. Orbit capture with >40% of the launch mass was shown to be possible at either target, with mission transfer times of 7.5 years and 13.5 years for Saturn and Uranus, respectively. Significant follow-on mission activities near Saturn (e.g. to Titan & Enceladus) were also possible by carrying extra propellant mass while remaining under the total wet mass limit.

Karp, Ashley C.↗