SEARCH · Search NASA

Results for “Engine Ground Testing”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40

All sources NASA NTRS DOE OSTI

NASA NTRS1976

Space Shuttle noise suppression concepts for the Eastern Test Range

The basic objectives of the Space Shuttle noise suppression program for the Eastern Test Range were the definition of the acoustic environment of the Shuttle and the adjacent ground plane for both on-pad and liftoff conditions and the definition of realistic noise suppression techniques and modification of the launch facility that could reduce engine noise associated with supersonic flow. Scaling considerations for acoustic model testing based on the principle of dynamic similarity are detailed. Suppression approaches are described with emphasis placed on barriers and shields: exhaust flow trench covers, solid dividers between the SSME and SRB exhaust flows and a crossed pipe water injection system over the SSME exhaust flow trench. Graphs are presented summarizing noise data gathered for various noise sources and using different suppression approaches.

Guest, S. H.↗

NASA NTRS1984

A large-scale investigation of V/STOL ground effects

A large-scale ground-effects test of a single jet in hover was conducted as a first-case study for future tests to provide the V/STOL community with an improved data base. The objectives for this single-jet hover test were to (1) document the jet characteristics and then (2) gather the associated force data. These data are then compared with results obtained from existing prediction methods. A conically convergent nozzle was mounted to a turbojet engine, and an 8-ft-diam suckdown-plate model measured the lift-loss forces in ground effect. Jet-exit characteristics (pressure profile, temperature, turbulence, etc.) are documented for several nozzle pressure ratios. Characteristics that may give rise to scale effects are discussed. Results from this first study indicate that small-scale tests, and current prediction methods, will lead to significant errors in the lift-loss estimation of a single-jet configured aircraft, hovering in ground effect.

Christiansen, R. S.↗

NASA NTRSDate not supplied

NASA’s Quiet Electric ENgines (QUEEN): Thermal Analysis and Testing of the Electronic Speed Controller (ESC)

An electric ducted fan system was tested at the NASA Glenn Research Center. Main components of the system include a commercial-off-the-Shelf (COTS) fan and motor, electronic speed controller, and cooling system. Motor speed, voltage, current, and temperatures were measured in this static ground test of the propulsor. The thermal performance of the Electronic Speed Controller (ESC) was also measured using two different methods to cool the ESC: air cooling and cold plate cooling. This propulsor prototype is one of NASA’s Quiet Electric ENgines (QUEENs) and is designated the ‘QUEEN V1.’ The Quiet Electric Engines are being developed for the 25% scale model of the Subsonic Single Aft Engine (SUSAN) Flight Research Vehicle and are intended to explore the potential of distributed electric propulsion for large regional single-aisle aircraft. Lessons learned will be used to guide development of future QUEEN prototypes and thermal management systems.

Firas G Asfoor↗

NASA NTRS2015

Cryogenic Orbital Testbed (CRYOTE) Ground Test Article, Final Report

Liquid propulsion has been used since Robert Goddard started developing a liquid oxygen (LO2) and gasoline powered rocket and fired it in 1923 (Ref. 1). In the following decades engineers settled on the combination of liquid hydrogen (LH2) and LO2 as the most efficient propellant combination for in-space travel. Due to their low temperatures (LH2 at 20 K and LO2 at 90 K), they require special handling and procedures. General Dynamics began developing LO2 and LH2 upper stages in 1956 in the form of Centaur, these efforts were soon funded by the Department of Defense in conjunction with NASA (beginning in 1958) (Ref. 2). Meanwhile NASA also worked with McDonnell Douglas to develop the SIV-B stage for the Saturn V rocket. In the subsequent years, the engineers were able to push the Centaur to up to 9 hr of orbital lifetime and the SIV-B to up to 6 hr. Due to venting the resultant boil-off from the high heat loads through the foam insulation on the upper stages, both vehicles remained in a settled configuration throughout the flights, thus the two phases of propellant (liquid and vapor) were separated at a known location. The one exception to this were the Titan/Centaur missions, which thanks to the lower boil-off using three layers of multilayer insulation (MLI), were able to coast unsettled for up to 5.25 hr during direct geosynchronous orbit insertion missions. In the years since there has been a continuous effort to extend the life of these upper stages from hours to days or even months.

Joule-Thompson Effect↗

DOE OSTI2020

HEMP Testing of Substation Yard Circuit Breaker Control and Protective Relay Circuits

There are concerns about the effects of High-Altitude Electromagnetic Pulses (HEMP) on the electric power grid. Activities to date tested and analyzed vulnerability of digital protective relays (DPRs) used in power substations, but the effect of HEMP on the greater substation environment is not well known. This work establishes a method of testing the vulnerability of circuit breaker control and protective relay circuits to the radiated E1 pulse associated with HEMP based on coupling to the cables in a substation yard. Two DPRs from Schweitzer Engineering Laboratories, Inc. were independently tested. The test setup also included a typical cable in a substation yard with return plane to emulate the ground grid and other ground conductors near the yard cable, cabinetry housing the installed DPRs, station battery and battery charger, terminal block elements, and a breaker simulator to emulate a substation yard configuration. The DPRs were powered from the station battery and the transformer inputs energized with a three-phase source to maintain typical operating conditions during the tests. Vulnerability testing consisted of a conducted E1 pulse injected into the center of the yard cable of the DPR circuits. Current measurements on the yard cable and DPR inputs indicated significant attenuation of the conducted pulse arriving at the control house equipment from the emulated substation yard. This reduction was quantified with respect to the equivalent open-circuit voltage on the yard cable. No equipment damage or undesired operation occurred on the tested circuits for values below 180 kV, which is significantly higher than the anticipated coupling to a substation yard cable.

24 POWER TRANSMISSION AND DISTRIBUTION↗

NASA NTRSDate not supplied

Lunar Proving Grounds Definition

The Lunar Surface Innovation Consortium (LSIC) is hosting a hybrid Lunar Proving Grounds Definition Workshop, July 12-13,2023, at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and on Zoom. The topic of facilities needed for testing hardware destined for the Moon and the need for Earth-based ‘Lunar Proving Grounds’ for testing systems has come up across all six Focus Areas of LSIC. While facilities exist for component- and instrument- level technology maturation (e.g., up to system/subsystem demo in relevant environments), and there are potential flight opportunities for component maturation to flight-qualified and even flight-proved systems, the Artemis Program vision for a sustained presence and transition to industry (e.g., the Moon to Mars Objectives and the LSIC “Path to an Enduring Lunar Presence” white paper) suggests an architecture of integrated systems and systems of systems more complex than Apollo or the International Space Station. Some questions we aim to address through this workshop include: (1) How will validation and verification of these systems and interactions, including human-robotic operations, be accomplished? (2) What metrics need to be tested, and thus what capabilities will such a facility or facilities need? (3) Which functionalities can be tested separately and which need to synergize? What can be the role of digital engineering?

Proving Grounds↗

NASA NTRS1991

Ground test program for a full-size solar dynamic heat receiver

Test hardware, facilities, and procedures were developed to conduct ground testing of a full-size, solar dynamic heat receiver in a partially simulated, low earth orbit environment. The heat receiver was designed to supply 102 kW of thermal energy to a helium and xenon gas mixture continuously over a 94 minute orbit, including up to 36 minutes of eclipse. The purpose of the test program was to quantify the receiver thermodynamic performance, its operating temperatures, and thermal response to changes in environmental and power module interface boundary conditions. The heat receiver was tested in a vacuum chamber using liquid nitrogen cold shrouds and an aperture cold plate. Special test equipment was designed to provide the required ranges in interface boundary conditions that typify those expected or required for operation as part of the solar dynamic power module on the Space Station Freedom. The support hardware includes an infrared quartz lamp heater with 30 independently controllable zones and a closed-Brayton cycle engine simulator to circulate and condition the helium-xenon gas mixture. The test article, test support hardware, facilities, and instrumentation developed to conduct the ground test program are all described.

Sedgwick, L. M.↗

NASA NTRS1974

MSFC Skylab airlock module, volume 2

System design and performance of the Skylab Airlock Module and Payload Shroud are presented for the communication and caution and warning systems. Crew station and storage, crew trainers, experiments, ground support equipment, and system support activities are also reviewed. Other areas documented include the reliability and safety programs, test philosophy, engineering project management, and mission operations support.

Source record↗

NASA NTRSDate not supplied

Physics and Modeling of Quasi-Steady and Forced Shock Trains

The dual-mode scramjet is a propulsive concept for contemporary hypersonic vehicles promising flight cruise speeds upwards of Mach 5. Despite decades of development and a recent resurgence in interest, such engines are not routinely deployed for commercial or military purposes. Instead, they have been confined to the realm of ground-test research and limited one-off flight test missions. One of the key stumbling blocks on the critical path to deployment of a dual-mode scramjet is the optimal design and stable operation of the isolator, a typically constant area duct that separates the scramjet inlet from the combustor. During ramjet mode at Mach numbers from 3 to 5 and during the transition to scramjet mode at higher Mach numbers, the isolator contains the pseudo-shock. Necessary to meet the back-pressure in the combustor, the pseudo-shock is typically divided into a shock dominated shock train region followed by a turbulence driven mixing region. Fluctuations in combustor pressure due to vehicle maneuvering, throttling, or combustion instabilities drive the shock train to shift streamwise within the isolator. In response to sharp pressure fluctuations, the shock train is unable to stabilize within the isolator, and the scramjet unstarts by ejecting the shock train out the inlet. This work addresses three key gaps in understanding of the isolator pseudo-shock. The phenomenon is studied in three experimental facilities to investigate the quasi-steady and unsteady fluid dynamics of the shock train in fueled and un-fueled test conditions. The strong link between boundary layer morphology and shock train structure is studied in detail and used as a tool to evaluate the state-of-the-art definitions and models of the pseudo-shock. Identifying the limitations of these models, a new process driven flux-conserved pseudo-shock model is proposed. This provides a computationally efficient model grounded in the fluid dynamic mechanisms of the pseudo-shock with better predictive capability than the current state-of-the-art across all facilities tested. The unsteady behavior of the shock train is further investigated to identify and understand two distinct forced dynamic modes: mechanically induced, low-rate forcing and high-rate combustion driven unsteadiness that sheds upstream propagating shocks. The proposed process driven model is found to be effective in the the limiting case of high-rate combustion driven unsteadiness by evaluating the model in a shock stationary reference frame. Further analysis identifies the approximately rigid chain motion of the shock train structure to mechanically induced forcing. The time delay between the onset of forced dynamics is found to saturate to a constant value and maximum shock train speed along the isolator with respect to the perturbation rate of change. The result of this work provides dual-mode scramjet designers with improved tools and physical understanding to develop more efficient, robust, and capable propulsion systems for hypersonic vehicles.

JAXA↗

NASA NTRS1981

The development and flight test evaluation of an integrated propulsion control system for the HiMAT research airplane

The Highly Maneuverable Aircraft Technology airplane is a .44-scale version of an advanced fighter design. It is remotely piloted from a ground cockpit and is powered by a J85-GE-21 turbojet engine. The engine is electronically controlled by a digital computer onboard the airplane to operate at selected engine operation modes. The HiMAT design and development philosophy emphasized high-risk, low-cost and minimum testing, and also required that no single failure would cause loss of the vehicle. This philosophy generated unique requirements for design, computer simulation methods, specialized test techniques, and support systems which are discussed in this paper.

Baer-Riedhart, J. L.↗

NASA NTRS2006

Characterization of Hollow Cathode Performance and Thermal Behavior

Hollow cathodes are one of the main life-limiting components in ion engines and Hall thrusters. Although state-of-the-art hollow cathodes have demonstrated up to 30,352 hours of operation in ground tests with careful handling, future missions are likely to require longer life, more margin and greater resistance to reactive contaminant gases. Three alternate hollow cathode technologies that exploit different emitter materials or geometries to address some of the limitations of state-of-the-art cathodes are being investigated. Performance measurements of impregnated tungsten-iridium dispenser cathodes at discharge currents of 4 to 15 A demonstrated that they have the same operating range and ion production efficiency as conventional tungsten dispenser cathodes. Temperature measurements indicated that tungsten-iridium cathodes also operate at the same emitter temperatures. They did not exhibit the expected reduction in work function at the current densities tested. Hollow cathodes with lanthanum hexaboride emitters operated over a wide current range, but suffered from lower ion production efficiency at currents below about 12.4 A because of higher insert heating requirements. Differences in operating voltages and ion production rates are explained with a simple model of the effect of cathode parameters on discharge behavior.

ion engines↗

NASA NTRS1984

Control system testing

A three stage process of ground testing of the Space Telescope Pointing Control System is used for verification prior to on-orbit operation. First, development tests are conducted in a laboratory environment using flight/engineering model control sensor and actuators configured with an engineering model of the flight computer and data management system breadboards. These development tests validate the results of computer simulations predicting control system performance. Integration tests bring together flight system elements and software interfaced to a software simulation of vehicle dynamics to confirm closed loop performance. The final ground test phase, flight systems testing, is conducted on the fully assembled Space Telescope, verifies interfaces with the Fine Guidance Sensors and includes a thermal vacuum testing period. During the final test phase, the Point Control System is exercised with the dynamics simulator running in real time.

Whittler, W. H.↗

NASA NTRSDate not supplied

Status of Mars Retropropulsion Testing in the Langley Unitary Plan Wind Tunnel

Future Mars human landings will be enabled by a powered descent phase starting at supersonic conditions, something which has never been done before on a Mars mission. Significant aerosciences challenges exist due to jet interactions between the retrorocket engine plumes, freestream flow, and vehicle that will affect the aerodynamic behavior during powered descent. Historically, wind tunnel tests have been used to study the interactions with inert gas exhaust simulants in place of rocket engines. On the computational side, flowfield simulations have been completed at full-scale conditions, but the available ground and flight data are not appropriate for calibrating computational uncertainties for aerodynamic interference on proposed Mars descent vehicles, due to insufficient data, dissimilar vehicle geometries, and disparate operating conditions. A wind tunnel test has been designed to begin addressing powered descent aerodynamics risks for large-scale human Mars entry concepts and to identify gaps in computational predictive capabilities. The test will be conducted in the NASA Langley Unitary Plan Wind Tunnel and is designed with improvements in model design and data products over past tests. The test campaign will be run using sub-scale model geometries derived from NASA powered descent reference vehicles: a blunt low lift-to-drag vehicle and a more slender geometry that generates higher unpowered lift. Both models have been fabricated and are ready for testing. The blunt model is equipped with the flexibility to examine the effects of nozzle pointing direction, number, location, size, and area ratio. The main measurements are heatshield aerodynamic interference forces and moments with a custom flow-through balance, discrete and distributed heatshield pressure, and high-speed flowfield visualization. This paper covers the test objectives, facility, models and instrumentation, and planned test matrix.

Mars↗

NASA NTRSDate not supplied

Status of Mars Retropropulsion Testing in the Langley Unitary Plan Wind Tunnel

Supersonic Retropropulsion↗

NASA NTRS2015

Subscale Validation of the Subsurface Active Filtration of Exhaust (SAFE) Approach to NTP Ground Testing

Brief History of NTP: Project Rover Began in 1950s by Los Alamos Scientific Labs (now Los Alamos National Labs) and ran until 1970s Tested a series of nuclear reactor engines of varying size at Nevada Test Site (now Nevada National Security Site) Ranged in scale from 111 kN (25 klbf) to 1.1 MN (250 klbf) Included Nuclear Furnace-1 tests Demonstrated the viability and capability of a nuclear rocket engine test program One of Kennedys 4 goals during famous moon speech to Congress Nuclear Engines for Rocket Vehicle Applications (NERVA) Atomic Energy Commission and NASA joint venture started in 1964 Parallel effort to Project Rover was focused on technology demonstration Tested XE engine, a 245-kN (55-klbf) engine to demonstrate startup shutdown sequencing. Hot-hydrogen stream is passed directly through fuel elements potential for radioactive material to be eroded into gaseous fuel flow as identified in previous programs NERVA and Project Rover (1950s-70s) were able to test in open atmosphere similar to conventional rocket engine test stands today Nuclear Furance-1 tests employed a full scrubber system Increased government and environmental regulations prohibit the modern testing in open atmosphere. Since the 1960s, there has been an increasing cessation on open air testing of nuclear material Political and national security concerns further compound the regulatory environment

Test Facilities↗

NASA NTRS1999

CVD Rhenium Engines for Solar-Thermal Propulsion Systems

Solar-thermal upper-stage propulsion systems have the potential to provide specific impulse approaching 900 seconds, with 760 seconds already demonstrated in ground testing. Such performance levels offer a 100% increase in payload capability compared to state-of-the-art chemical upper-stage systems, at lower cost. Although alternatives such as electric propulsion offer even greater performance, the 6- to 18- month orbital transfer time is a far greater deviation from the state of the art than the one to two months required for solar propulsion. Rhenium metal is the only material that is capable of withstanding the predicted thermal, mechanical, and chemical environment of a solar-thermal propulsion device. Chemical vapor deposition (CVD) is the most well-established and cost-effective process for the fabrication of complex rhenium structures. CVD rhenium engines have been successfully constructed for the Air Force ISUS program (bimodal thrust/electricity) and the NASA Shooting Star program (thrust only), as well as under an Air Force SBIR project (thrust only). The bimodal engine represents a more long-term and versatile approach to solar-thermal propulsion, while the thrust-only engines provide a potentially lower weight/lower cost and more near-term replacement for current upper-stage propulsion systems.

Williams, Brian E.↗

NASA NTRSDate not supplied

Maryland Space Weather UnderGround (SWUG) Educational Outreach Program for Solar Eclipse Study

Space Weather UnderGround (SWUG) is an educational outreach program that provides hands-on experiences in Science, Technology, Engineering, and Mathematics (STEM) to high school and undergraduate students. It has three ultimate goals: 1. Educating the future STEM workforce. 2. Building a cost-effective, research-capable ground 3. magnetometer array across the United States. Collecting geomagnetic field data at high spatial resolution for heliophysics research. SWUG students build, test, and deploy the Simple Aurora Monitor (SAM)-III kit, purchased by Reeve Engineers. The SAM-III kit is a fluxgate magnetometer that measures geomagnetic field changes at a resolution of 1 nT/sec. Dr. Charles Smith initiated the SWUG program at the University of New Hampshire, and it has since expanded to Alaska and Maryland. This presentation introduces the Maryland SWUG activities. The MD-SWUG program was started in the Fall of 2022 with the goal of deploying magnetometers to the solar eclipse sites in 2023 and 2024. Two student-built magnetometers were deployed to the Southwest Research Institute and the Los Alamos National Laboratory for the 2023 annular solar eclipse, with plans to deploy at least four magnetometers to the 2024 total solar eclipse sites, including the University of Texas at Dallas. During a solar eclipse, reduced solar irradiance weakens ionospheric currents and reduces geomagnetic fields by up to 30 nT at the eclipse sites. A recent study suggested that solar eclipses impact geomagnetic fields not only along the eclipse path but also at their magnetic conjugate locations. The SWUG program will help us understand this electrodynamic coupling between the conjugate locations during a solar eclipse by providing better data coverage along the solar eclipse path.

Hyunju Connor↗

NASA NTRS1994

U.S. In-Space Electric Propulsion Experiments

Arcjet and ion propulsion offer potentially significant reductions in the mass of propulsion systems required for Earth orbiting satellites and planetary spacecraft. For this reason, they have been the subject of validation and demonstration programs. After examining the benefits of electric propulsion, this paper discusses the technology base for the Electric propulsion Space Experiment (ESEX) arcjet demonstration experiment and the NASA SEP Technology Application Readiness (NSTAR) ion propulsion validation program. As part of the Advanced Research and Global Observation Spacecraft (ARGOS), ESEX will perform ten 15-minute firings of a 30 kW ammonia arcjet. NASA's validation program, NSTAR, consists of two major elements: a ground-test element and an in-space experiment. The ground-test element will validate the life, intergrability, and performance of low-power ion propulsion. The in-space element will demonstrate the feasibility of integrating and flying an ion propulsion system. The experiment will measure the interactions among the ion propulsion system, the host spacecraft, and the surrounding space plasma; and it will provide a quantitative assessment of the ability of ground testing to replicate the in-space performance of ion thrusters. By involving industry in NSTAR, a commercial source for this technology will be ensured. Furthermore, the successful completion of the NSTAR validation program will stimulate commercial and government (both civilian and military) uses of this technology.

arcjet↗