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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 37 records · Page 2

Aerothermodynamic Testing and Boundary Layer Trip Sizing of the HIFiRE Flight 1 Vehicle

An experimental wind tunnel test was conducted in the NASA Langley Research Center s 20-Inch Mach 6 Air Tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this report is focused on the Flight 1 configuration, the first in a series of flight experiments. This report documents experimental measurements made over a range of Reynolds numbers and angles of attack on several scaled ceramic heat transfer models of the Flight 1 payload. Global heat transfer was measured using phosphor thermography and the resulting images and heat transfer distributions were used to infer the state of the boundary layer on the vehicle windside and leeside surfaces. Boundary layer trips were used to force the boundary layer turbulent, and a brief study was conducted to determine the effectiveness of the trips with various heights. The experimental data highlighted in this test report were used to size and place the boundary layer trip for the flight test vehicle.

Berger, Karen T.↗

Aerothermodynamic Testing and Boundary Layer Trip Sizing of the HIFiRE Flight 1 Vehicle

An experimental wind tunnel test was conducted in the NASA Langley Research Center s 20-Inch Mach 6 Air Tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this article is focused on the Flight 1 configuration, the first in a series of flight experiments. The article documents experimental measurements made over a Reynolds numbers range of 2.1x10(exp 6)/ft to 5.6x10(exp 6)/ft and angles of attack of -5 to +5 deg on several scaled ceramic heat transfer models of the Flight 1 configuration. Global heat transfer was measured using phosphor thermography and the resulting images and heat transfer distributions were used to infer the state of the boundary layer on the vehicle windside and leeside surfaces. Boundary layer trips were used to force the boundary layer turbulent and the experimental data highlighted in this article were used to size and place the boundary layer trip for the flight vehicle. The required height of the flight boundary layer trip was determined to be 0.079 in and the trip was moved from the design location of 7.87 in to 20.47 in to ensure that augmented heating would not impact the laminar side of the vehicle. Allowable roughness was selected to be 3.2x10(exp -3) in.

Berger, Karen T.↗

Aerothermodynamic Characteristics of Boundary Layer Transition and Trip Effectiveness of the HIFiRE Flight 5 Vehicle

An experimental wind tunnel test was conducted in the NASA Langley Research Center s 20-Inch Mach 6 Tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this report is focused on the Flight 5 configuration, one in a series of flight experiments. This report documents experimental measurements made over a range of Reynolds numbers and angles of attack on several scaled ceramic heat transfer models of the Flight 5 vehicle. The heat transfer rate was measured using global phosphor thermography and the resulting images and heat transfer rate distributions were used to infer the state of the boundary layer on the windside, leeside and side surfaces. Boundary layer trips were used to force the boundary layer turbulent, and a study was conducted to determine the effectiveness of the trips with various heights. The experimental data highlighted in this test report were used determine the allowable roughness height for both the windside and side surfaces of the vehicle as well as provide for future tunnel-to-tunnel comparisons.

Berger, Karen T.↗

Understanding the setting and hardening process of wollastonite-based brushite cement. Part 2: Influence of the boron and aluminum concentrations in the mixing solution

The mixing solution of wollastonite-based brushite cement is a phosphoric acid solution containing metallic cations and borax. This work complements a previous study devoted to the influence of the H{sub 3}PO{sub 4} concentration, Ca/P and liquid-to-solid (l/s) ratios on the setting and hardening process of the binder by providing new insight into the role of aluminum and boron. Boron retards the setting and decreases the heat released during the process. It also contributes to reduce the macroporosity of the hardened material but yields to poor compressive strength. With aluminum in the mixing solution, the mechanical properties are greatly improved thanks to the precipitation of an amorphous aluminophosphate which increases the density of the cement matrix. But aluminum alone leads to fast setting. A joint addition of boron and aluminum to the mixing solution makes it possible to get a material with optimized properties both in fresh and hardened states.

36 MATERIALS SCIENCE↗

Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel

An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

Liechty, Derek S.↗

Phosphor thermometry device for synchronized acquisition of luminescence lifetime decay and intensity on thermal barrier coatings

A phosphor thermometry device includes a laser that generates a laser pulse onto a thermal barrier coating (TBC) applied onto a substrate. A metallic bond coat layer is on the substrate. A ceramic top coat layer is on the bond coat layer and includes an undoped layer and a doped sensing layer having co-doped first and second rare-earth luminescent dopants that emit respective first and second different emission wavelengths upon excitation by the laser pulse. A detector receives reflected, convoluted luminescence signals from the TBC. First and second photomultiplier devices detect respective first and second different emission wavelengths of the convoluted luminescence signals. A controller receives and processes signals generated from respective first and second photomultiplier devices and determines luminescence lifetime decay and intensity variations for each of the respective first and second rare-earth luminescent dopants for temperature monitoring of the TBC.

Fouliard, Quentin↗

Development of sensors for ceramic components in advanced propulsion systems

The 'Development of Sensors for Ceramics Components in Advanced Propulsion Systems' program was divided into two phases. The objectives of Phase 1 were to analyze, evaluate and recommend sensor concepts for the measurement of surface temperature, strain and heat flux on ceramic components for advanced propulsion systems. The results of this effort were previously published in NASA CR-182111. As a result of Phase 1, three approaches were recommended for further development: pyrometry, thin-film sensors, and thermographic phosphors. The objectives of Phase 2 were to fabricate and conduct laboratory demonstration tests of these systems. A summary report of the Phase 2 effort, together with conclusions and recommendations for each of the categories evaluated, has been submitted to NASA. Emittance tests were performed on six materials furnished by NASA Lewis Research Center. Measurements were made of various surfaces at high temperature using a Thermogage emissometer. This report describes the emittance test program and presents a summary of the results.

Atkinson, William H.↗

Development of Sensors for Ceramic Components in Advanced Propulsion Systems: Temperature Sensor Systems Evaluation - Phase 2

The 'development of sensors for ceramic components in advanced propulsion systems' program is divided into two phases. The objectives of Phase 1 were to analyze, evaluate and recommend sensor concepts for the measurement of surface temperature, strain and heat flux on ceramic components for advanced propulsion systems. The results of this effort were previously published in NASA CR-182111. As a result of Phase 1, three approaches were recommended for further development: pyrometry, thin-film sensors, and thermographic phosphors. The objective of Phase 2 were to fabricate and conduct laboratory demonstration tests of these systems. Six materials, mutually agreed upon by NASA and Pratt & Whitney, were investigated under this program. This report summarizes the Phase 2 effort and provides conclusions and recommendations for each of the categories evaluated.

Atkinson, W. H.↗

Rare-earth doped thermal barrier coating bond coat for thermally grown oxide luminescence sensing

A thermal barrier coated component, such as a turbine blade formed from a superalloy substrate, includes a thermal barrier coating applied onto the substrate. A metallic bond coat layer is on the substrate and includes rare-earth luminescent dopants. A ceramic top coat layer is on the bond coat layer. A temperature sensing thermally grown oxide (TGO) layer is formed at the interface of the bond coat layer and ceramic top coat layer. The temperature sensing TGO layer includes grown rare-earth luminescent ions migrated from the metallic bond coat layer in an amount sufficient to enable luminescence sensing of the TGO layer for real-time phosphor thermometry temperature measurements at the TGO layer.

Fouliard, Quentin↗

Method for forming a temperature sensing layer within a thermal barrier coating

A thermal barrier coated component, such as a turbine blade formed from a superalloy substrate, includes a thermal barrier coating applied onto the substrate. A metallic bond coat layer is on the substrate and includes rare-earth luminescent dopants. A ceramic top coat layer is on the bond coat layer. A temperature sensing thermally grown oxide (TGO) layer is formed at the interface of the bond coat layer and ceramic top coat layer. The temperature sensing TGO layer includes grown rare-earth luminescent ions migrated from the metallic bond coat layer in an amount sufficient to enable luminescence sensing of the TGO layer for real-time phosphor thermometry temperature measurements at the TGO layer.

Fouliard, Quentin↗

SXI prototype mirror mount

The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve the design, assembly and alignment of the telescope. Finally, a high level assembly and alignment plan for the entire telescope was prepared by UAH. This plan addresses the sequence of assembly, the required assembly and alignment tolerances, and the methods to verify the alignment at each step during the assembly process. This assembly and alignment plan will be used to assemble and integrate the engineering model (EM) of the telescope. Later on, based on this plan more detailed assembly and alignment procedures will be developed for the lower-level assemblies of SXI.

Source record↗

Distributed Sand-Grain Roughness Effects on Blunt Body Hypersonic Transition and Heating

An experimental investigation of distributed sand-grain surface roughness effects on boundary-layer transition and convective heating has been performed. Two representative entry vehicle geometries, a spherical-cap aeroshell and a sphere-cone aeroshell, were considered. Multiple cast ceramic wind tunnel models of each geometry were fabricated with various roughness heights to simulate an ablated thermal protection system. Wind tunnel testing was performed at Mach 6 over a range of Reynolds numbers sufficient to produce laminar, transitional, and turbulent flow. Aeroheating and boundary-layer transition onset data were obtained using global phosphor thermography. The experimental heating data are presented herein, as are comparisons to laminar and turbulent smooth-wall heat transfer distributions from computational flow field simulations.

Brian R. Hollis↗

X-33 Experimental Aeroheating at Mach 6 Using Phosphor Thermography

The goal of the NASA Reusable Launch Vehicle (RLV) technology program is to mature and demonstrate essential, cost effective technologies for next generation launch systems. The X-33 flight vehicle presently being developed by Lockheed Martin is an experimental Single Stage to Orbit (SSTO) demonstrator that seeks to validate critical technologies and insure applicability to a full scale RLV. As with the design of any hypersonic vehicle, the aeroheating environment is an important issue and one of the key technologies being demonstrated on X-33 is an advanced metallic Thermal Protection System (TPS). As part of the development of this TPS system, the X-33 aeroheating environment is being defined through conceptual analysis, ground based testing, and computational fluid dynamics. This report provides an overview of the hypersonic aeroheating wind tunnel program conducted at the NASA Langley Research Center in support of the ground based testing activities. Global surface heat transfer images, surface streamline patterns, and shock shapes were measured on 0.013 scale (10-in.) ceramic models of the proposed X-33 configuration in Mach 6 air. The test parametrics include angles of attack from -5 to 40 degs, unit Reynolds numbers from 1x106 to 8x106/ft, and body flap deflections of 0, 10, and 20 deg. Experimental and computational results indicate the presence of shock/shock interactions that produced localized heating on the deflected flaps and boundary layer transition on the canted fins. Comparisons of the experimental data to laminar and turbulent predictions were performed. Laminar windward heating data from the wind tunnel was extrapolated to flight surface temperatures and generally compared to within 50 deg F of flight prediction along the centerline. When coupled with the phosphor technique, this rapid extrapolation method would serve as an invaluable TPS design tool.

Horvath, Thomas J.↗

Experimental Investigation of Hexcomb-Pattern Roughness Effects on Transition Onset and Turbulent Heating Augmentation at Mach 6

An experimental investigation of hexcomb-patterned surface roughness effects on boundary-layer transition and turbulent heating has been performed. Two representative entry vehicle geometries, a spherical- cap aeroshell and a sphere-cone aeroshell, were considered. Multiple cast ceramic models of each geometry were fabricated with varying roughness pattern densities and depths that simulated an ablated hexcomb-structure thermal protection system. Wind tunnel testing was performed at Mach 6 over a range of Reynolds numbers sufficient to produce laminar, transitional, and turbulent flow. Aeroheating and boundary-layer transition onset data were obtained using global phosphor thermography. The experimental heating data are presented herein, as are comparisons to laminar and turbulent smooth-w ll heat transfer distributions from computational flow field simulations.

Hollis, Brian R.↗

Hexcomb Pattern Roughness Effects on Blunt Body Transition and Heating

An experimental investigation of hexcomb pattern surface roughness effects on boundary-layer transition and convective heating has been performed. Two representative entry vehicle geometries, a spherical-cap aeroshell and a sphere-cone aeroshell, were considered. Multiple cast ceramic models of each geometry were fabricated with various roughness pattern densities and depths that simulated an ablated hexcomb-structure thermal protection system. Wind tunnel testing was performed at Mach 6 over a range of Reynolds numbers sufficient to produce laminar, transitional, and turbulent flow. Aeroheating and boundary-layer transition onset data were obtained using global phosphor thermography. The experimental heating data are presented herein, as are comparisons to laminar and turbulent smooth-wall heat transfer distributions from computational flow field simulations. The experimental data were used to develop a unified boundary-layer transition correlation for both sandgrain distributed roughness and hexcomb pattern roughness.

Brian R Hollis↗

Experimental Investigation of Distributed Sand-Grain Roughness Effects on Transition Onset and Turbulent Heating at Mach 6

An experimental investigation of distributed sand-grain surface roughness effects on hypersonic boundary-layer transition and turbulent heating has been performed. Two representative entry vehicle geometries, a sphere-cone aeroshell and a spherical-cap aeroshell, were considered. Cast ceramic models of each geometry were fabricated with distributed sand-grain roughness patterns of different heights that simulated an ablated thermal protection system. Wind tunnel testing was performed at Mach 6 over a range of Reynolds numbers sufficient to produce laminar, transitional, and turbulent flow. Aeroheating and boundary-layer transition onset data were obtained using global phosphor thermography. The experimental heating data are presented herein, as are comparisons to laminar and turbulent smooth-wall heat transfer distributions from computational flow field simulations. The boundary-layer transition data were found to correlate with a functional representation developed in prior roughness studies, although the data scatter was greater owing to the height variability of distributed sand-grain roughness.

Brian R Hollis↗

Aerothermodynamic Testing of the Crew Exploration Vehicle in the LaRC 20-Inch Mach 6 and 31-Inch Mach 10 Tunnels

An experimental wind tunnel program is being conducted in support of a NASA wide effort to develop a Space Shuttle replacement and to support the Agency s long term objective of returning to the Moon and Mars. This article documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle Crew Module. The experimental data highlighted in this article are to be used to assess numerical tools that will be used to generate the flight aerothermodynamic database. Global heat transfer images and heat transfer distributions were obtained over a range of freestream Reynolds numbers and angles of attack with the phosphor thermography technique. Heat transfer data were measured on the forebody and afterbody and were used to infer the heating on the vehicle as well as the boundary layer state on the forebody surface. Several model support configurations were assessed to minimize potential support interference. In addition, the ability of the global phosphor thermography method to provide quantitative heating measurements in the low temperature environment of the capsule base region was assessed. While naturally fully developed turbulent levels were not obtained on the forebody, the use of boundary layer trips generated fully developed turbulent flow. Laminar and turbulent computational results were shown to be in good agreement with the data. Backshell testing demonstrated the ability to obtain data in the low temperature region as well as demonstrating the lack of significant model support hardware influence on heating.

Berger, Karen T.↗