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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.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Measuring Combustion Advance in Solid Propellants

Set of gauges on solid-propellant rocket motor with electrically insulating case measures advance of combustion front and local erosion rates of propellant and insulation. Data furnished by gauges aid in motor design, failure analysis, and performance prediction. Technique useful in determining propellant uniformity and electrical properties of exhaust plum. Gauges used both in flight and on ground. Foilgauge technique also useful in basic research on pulsed plasmas or combustion of solids.

Yang, L. C.↗
NASA NTRS1976

Advanced combustion techniques for controlling NO sub x emissions of high altitude cruise aircraft

An array of experiments designed to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere was discussed. Of particular concern are the oxides of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

Rudey, R. A.↗
NASA NTRS1976

Advanced combustion techniques for controlling NO/x/ emissions of high altitude cruise aircraft

An array of experiments have been and continue to be sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere. Of particular concern are the oxides of nitrogen (NO/x/) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NO/x/ emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

Rudey, R. A.↗
NASA NTRSDate not supplied

Advanced Combustion via Microgravity Experiments (ACME) on the International Space Station (ISS)

Experimental studies of laminar, non-premixed flames of gaseous fuels are underway on the International Space Station (ISS) as part of NASA’s Advanced Combustion via Microgravity Experiments(ACME) project. The research is primarily focused on improving practical terrestrial combustion through fundamental microgravity research, where a secondary objective is spacecraft fire safety. Example goals are to improve understanding of flame stability and extinction limits, soot control and reduction, oxygen-enriched combustion which could enable practical carbon sequestration, combustion at fuel lean conditions where both optimum performance and low emissions can be achieved, the use of electric fields for combustion control, cool flame chemical kinetics, and materials flammability. The microgravity environment avoids buoyancy-induced flicker and enables the creation of spherical flames, allowing numerical models to focus computational power on transport phenomena and chemical kinetics. Compared to normal gravity, microgravity also provides longer residence times and larger length scales, yielding a broad range of flame conditions which are beneficial for simplified analysis, e.g., of limit behavior where chemical kinetics are important. Using modular hardware, research for six independent investigations is being carried out within the station’s Combustion Integrated Rack (CIR). While the ISS crew members set up the experimental hardware, the tests are remotely commanded with investigator input from the NASA Glenn Research Center. Over a thousand flames have been ignited since ACME operations began in Sept. 2017 and selected results from the first five experiments are summarized.

laminar flames↗
NASA NTRS2005

Advanced Combustion Modeling for Complex Turbulent Flows

The next generation of aircraft engines will need to pass stricter efficiency and emission tests. NASA's Ultra-Efficient Engine Technology (UEET) program has set an ambitious goal of 70% reduction of NO(x) emissions and a 15% increase in fuel efficiency of aircraft engines. We will demonstrate the state-of-the-art combustion tools developed a t Stanford's Center for Turbulence Research (CTR) as part of this program. In the last decade, CTR has spear-headed a multi-physics-based combustion modeling program. Key technologies have been transferred to the aerospace industry and are currently being used for engine simulations. In this demo, we will showcase the next-generation combustion modeling tools that integrate a very high level of detailed physics into advanced flow simulation codes. Combustor flows involve multi-phase physics with liquid fuel jet breakup, evaporation, and eventual combustion. Individual components of the simulation are verified against complex test cases and show excellent agreement with experimental data.

Ham, Frank Stanford↗
NASA NTRS1982

Evaluation of advanced combustion concepts for dry NO sub x suppression with coal-derived, gaseous fuels

The emissions performance of a rich lean combustor (developed for liquid fuels) was determined for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf (7.0 to 10.3 MJ/NCM). The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher. NOx generation from NH3 is significant at ammonia concentrations significantly less than 0.5%. These levels may occur depending on fuel gas cleanup system design. CO emissions, combustion efficiency, smoke and other operational performance parameters were satisfactory. A test was completed with a catalytic combustor concept with petroleum distillate fuel. Reactor stage NOx emissions were low (1.4g NOx/kg fuel). CO emissions and combustion efficiency were satisfactory. Airflow split instabilities occurred which eventually led to test termination.

Beebe, K. W.↗
NASA NTRSDate not supplied

ACME: Advanced Combustion via Microgravity Experiments

From Nov. 2017 to Feb. 2022, the ACME project’s six independent investigations of laminar, non-premixed flames of gaseous fuels were conducted on the International Space Station (ISS) in the Combustion Integrated Rack (CIR). An exploration of flames at the extremes of high sooting and high dilution was conducted with a coaxial coflow burner, where the fuel and oxidizer velocities were typically matched. An investigation of electric-field effects also used the same coflow burner as well as a simple gas-jet burner, with a circular electrode mesh downstream of the burner, at voltages of either polarity up to 10 kV. A study focused on material flammability in a quiescent atmosphere emulated the burning of condensed-phased fuels using cylindrical burners with a flat perforated outlet instrumented to measure the heat flux to the burner, i.e., emulated fuel. Three studies of soot processes, flame dynamics, and low-temperature combustion used porous spherical burners yielding a nominally one-dimensional flame structure. The ACME research will be represented through images and text.

flames↗
NASA NTRS1995

Advanced Subsonic Combustion Rig Developed

The Advanced Subsonic Combustion Rig (ASCR), a unique, state-of-the-art facility for conducting combustion research, is located at the NASA Lewis Research Center in Cleveland, Ohio. The ASCR, which was nearing completion at the close of 1995, will be capable of simulating the very high pressure and high temperature conditions that are expected to exist in future, advanced subsonic gas turbine (jet) engines. Future environmental regulations will require much cleaner burning (more environmentally friendly) aircraft engines. The ASCR is critical to the development of these cleaner engines. It will allow NASA and U.S. aircraft engine industry researchers to identify and test promising clean-burning gas turbine engine combustion concepts under the pressure and temperature conditions that are expected for those future engines. Combustion processes will be investigated for a variety of next-generation aircraft engine sizes, including engines for large, long-range aircraft (with typical trip lengths of about 3000 mi) and for regional aircraft (with typical trip lengths of about 400 mi). The ASCR design was conceived and initiated in 1993, and fabrication and construction of the rig, including the buildup of an advanced control room, took place throughout 1994 and 1995. In early 1996, the ASCR will be operational for obtaining research data. The ASCR is an intricate part of the NASA Advanced Subsonic Technology Propulsion Program, which is aimed at developing technologies critical to the next generation of gas turbine engines. This effort is in collaboration with the U.S. aircraft gas turbine engine industry. A goal of the Advanced Subsonic Technology Propulsion Program is to develop combustion concepts and technologies that will result in gas turbine engines that produce 50 percent less nitrous oxide (NO_x) pollutants than current engines do. This facility is unique in its capability to simulate advanced subsonic engine pressure, temperature, and air flow rate conditions. Specifically, it will provide operating temperatures up to 3000 F and pressures up to 60 atm. Under these conditions, researchers will obtain detailed combustion temperatures, pressures, and flow velocities as well as the chemical compositions of the combustion exhaust. Researchers also will be able to obtain data by using nonintrusive laser diagnostic techniques. The ASCR facility will be used to test fundamental combustion configurations (flametubes) for detailed study of combustion processes, to test sectors of gas turbine combustors to study the process in configurations more like those of aircraft engines, and in some cases to test full annular combustors.

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NASA NTRS1992

Design of a prototype Advanced Main Combustion Chamber for the Space Shuttle Main Engine

Development of a prototype advanced main combustion chamber is underway at NASA Marshall Space Flight Center. The Advanced Main Combustion Chamber (AMCC) project is being approached utilizing a 'concurrent engineering' concept where groups from materials, manufacturing, stress, quality, and design are involved from the initiation of the project. The AMCC design has been tailored to be compatible with the investment casting process. Jacket, inlet/outlet manifolds, inlet/outlet neck coolant flow splitters, support ribs, actuator lugs, and engine controller mounting bracket will all be a part of the one-piece AMCC casting. Casting of the AMCC in a one-piece configuration necessitated a method of forming a liner in its structural jacket. A method of vacuum plasma spraying the liner is being developed. In 1994, the AMCC will be hot-fired on the Technology Test Bed Space Shuttle Main Engine.

Lackey, J. D.↗
NASA NTRS1993

Advanced Main Combustion Chamber structural jacket strength analysis

The structural analysis of the Advanced Main Combustion Chamber (AMCC) is presented. The AMCC is an advanced fabrication concept of the Space Shuttle Main Engine main combustion chamber (MCC). Reduced cost and fabrication time of up to 75 percent were the goals of the AMCC with cast jacket with vacuum plasma sprayed or platelet liner. Since the cast material for the AMCC is much weaker than the wrought material for the MCC, the AMCC is heavier and strength margins much lower in some areas. Proven hand solutions were used to size the manifolds cutout tee areas for combined pressure and applied loads. Detailed finite element strength analyses were used to size the manifolds, longitudinal ribs, and jacket for combined pressure and applied local loads. The design of the gimbal actuator strut attachment lugs were determined by finite element analyses and hand solutions.

Johnston, L. M.↗
NASA NTRS1998

Advanced Subsonic Combustion Rig

Researchers from the NASA Lewis Research Center have obtained the first combustion/emissions data under extreme future engine operating conditions. In Lewis' new world-class 60-atm combustor research facility--the Advanced Subsonic Combustion Rig (ASCR)--a flametube was used to conduct combustion experiments in environments as extreme as 900 psia and 3400 F. The greatest challenge for combustion researchers is the uncertainty of the effects of pressure on the formation of nitrogen oxides (NOx). Consequently, U.S. engine manufacturers are using these data to guide their future combustor designs. The flametube's metal housing has an inside diameter of 12 in. and a length of 10.5 in. The flametube can be used with a variety of different flow paths. Each flow path is lined with a high-temperature, castable refractory material (alumina) to minimize heat loss. Upstream of the flametube is the injector section, which has an inside diameter of 13 in. and a length of 0.5-in. It was designed to provide for quick changeovers. This flametube is being used to provide all U.S. engine manufacturers early assessments of advanced combustion concepts at full power conditions prior to engine production. To date, seven concepts from engine manufacturers have been evaluated and improved. This collaborated development can potentially give U.S. engine manufacturers the competitive advantage of being first in the market with advanced low-emission technologies.

Lee, Chi-Ming↗
NASA NTRS1993

Adaptation of the Advanced Spray Combustion Code to Cavitating Flow Problems

A very important consideration in turbopump design is the prediction and prevention of cavitation. Thus far conventional CFD codes have not been generally applicable to the treatment of cavitating flows. Taking advantage of its two-phase capability, the Advanced Spray Combustion Code is being modified to handle flows with transient as well as steady-state cavitation bubbles. The volume-of-fluid approach incorporated into the code is extended and augmented with a liquid phase energy equation and a simple evaporation model. The strategy adopted also successfully deals with the cavity closure issue. Simple test cases will be presented and remaining technical challenges will be discussed.

Liang, Pak-Yan↗
NASA NTRS1983

Study of advanced rotary combustion engines for commuter aircraft

Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

Berkowitz, M.↗
NASA NTRS2004

NASA Glenn's Advanced Subsonic Combustion Rig Supported the Ultra-Efficient Engine Technology Project's Emissions Reduction Test

The Advanced Subsonic Combustor Rig (ASCR) is NASA Glenn Research Center's unique high-pressure, high-temperature combustor facility supporting the emissions reduction element of the Ultra-Efficient Engine Technology (UEET) Project. The facility can simulate combustor inlet test conditions up to a pressure of 900 psig and a temperature of 1200 F (non-vitiated). ASCR completed three sector tests in fiscal year 2003 for General Electric, Pratt & Whitney, and Rolls-Royce North America. This will provide NASA and U.S. engine manufacturers the information necessary to develop future low-emission combustors and will help them to better understand durability and operability at these high pressures and temperatures.

Beltran, Luis R.↗
NASA NTRS1992

Combustion synthesis of advanced materials

The combustion synthesis of ceramic-metal composites using an in-situ liquid infiltration technique is described. The effect of varying the reactants and their stoichiometry to provide a range of reactant and product species i.e. solids, liquids and gases, with varying physical properties e.g. thermal conductivity, on the microstructure and morphology of synthesized products is also described. Alternatively, conducting the combustion synthesis reaction in a reactive gas environment is also discussed, in which advantages can be gained from the synergistic effects of combustion synthesis and vapor phase transport. In each case, the effect of the presence or absence of gravity (density) driven fluid flow and vapor transport is discussed as is the potential for producing new and perhaps unique materials by conducting these SHS reactions under microgravity conditions.

Moore, J. J.↗
NASA NTRS2000

Gravitational Effects on Combustion Synthesis of Advanced Porous Materials

Combustion Synthesis (self-Propagating high-temperature synthesis-(SHS)) of porous Ti-TiB(x), composite materials has been studied with respect to the sensitivity to the SHS reaction parameters of stoichiometry, green density, gasifying agents, ambient pressure, diluents and gravity. The main objective of this research program is to engineer the required porosity and mechanical properties into the composite materials to meet the requirements of a consumer, such as for the application of bone replacement materials. Gravity serves to restrict the gas expansion and the liquid movement during SHS reaction. As a result, gravitational forces affect the microstructure and properties of the SHS products. Reacting these SHS systems in low gravity in the KC-135 aircraft has extended the ability to form porous products. This paper will emphasize the effects of gravity (low g, 1g and 2g) on the SHS reaction process, and the microstructure and properties of the porous composite. Some of biomedical results are also discussed.

Zhang, X.↗
NASA NTRS1990

Thermal analysis simulation for a spin-motor used in the advanced main combustion chamber vacuum plasma spray project using the SINDA computer program

One of the many design challenges of this project is predicting the thermal effects due to the environment inside the vacuum chamber on the turntable and spin motor spindle assembly. The objective of the study is to model the spin motor using the computer program System Improved Numerical Differencing Analyzer (SINDA). By formulating the appropriate input information concerning the motor's geometry, coolant flow path, material composition, and bearing and motor winding characteristics, SINDA should predict temperatures at various predefined nodes. From these temperatures, hopefully, one can predict if the coolant flow rate is sufficient or if certain mechanical elements such as bearings, O ring seals, or motor windings will exceed maximum design temperatures.

Mcdonald, Gary H.↗
NASA NTRS1991

Advanced main combustion chamber program

The topics presented are covered in viewgraph form and include the following: investment of low cost castings; usage of SSME program; usage of MSFC personnel for design effort; and usage of concurrent engineering techniques.

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