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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

PPI DataHub Project Data Package: S. elongatus PCC 7942 Limited Proteolysis and Thermal Proteome Profiling Structural Proteomics (JM-PB-DP3)

The purpose of this experiment was to investigate structural alterations in proteins involved in central carbon metabolism and photosynthetic electron transfer pathways in Synechococcus elongatus PCC 7942. Sample data was obtained from S. elongatus cell lysates using three complementary mass spectrometry (MS) techniques using limited proteolysis (LiP-MS), thermal proteome profiling (TPP-MS), and redox enrichment (Redox-MS) in evaluating alterations solvent accessibility and structural stability caused by light perturbation at the molecular level. Experimentally processed sample data for LiP and TPP proteomic datasets were derived from the same cell culture stock, prepared simultaneously in parallel, and acquired by mass spectrometry. Processed datasets are openly accessible from the download button and contain secondary processed proteomic results files, computed outputs, and supporting metadata materials. Experimental samples processed for LiP-MS label-free quantification (LFQ) or TPP-MS tandem mass tag (TMT) 10-plex were acquired using a Q-Exactive HF-X mass spectrometer and processed/compiled using either MSGF+ (v2024.03.26) or ​​​​PlexedPiper for proteome evaluation. Additional software supporting downstream proteomic analysis include FragPipe (v.4.0), MSFragger (v.22.1), and an adapted Microbial Isolate LiP Analysis Workflow (located at Zenodo). Processed proteomic data downloads include a sample naming key, normalized quantification results files, and processed protein annotated abundance files.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1975

Aerodynamic analysis of several high throat Mach number inlets for the quiet clean short-haul experimental engine

The results of an analytical study to investigate internal and external surface Mach numbers on several inlet geometries for possible application to the nacelle of the Quiet Clean Short-Haul Experimental Engine (QCSEE) are presented. The effects of external forebody geometry and internal lip geometry were illustrated at both low-speed and cruise conditions. Boundary-layer analyses were performed on several geometries to determine if lip flow separation might exist. The results indicated that inner-surface Mach number level and gradient could be reduced with inlets at a 50 deg incidence angle by blunting the external forebody geometry. The external Mach numbers at cruise conditions indicated that a compromise in the external forebody bluntness might be required to satisfy both low-speed and cruise conditions. For a fixed value of bluntness parameter, no lip flow separation was indicated for the 1.46- and 1.57-area-contraction-ratio inlets at low-speed conditions. However, a lip separation condition was obtained with the 1.37-contraction-ratio inlet. The QCSEE nacelle design takeoff operating condition (incidence angle of 50 deg and free-stream Mach number of 0.12) resulted in higher peak surface Mach numbers than the design crosswind (incidence angle of 90 deg and free-stream Mach number of 0.05) or static condition.

Albers, J. A.↗
NASA NTRS1976

Microcraters formed in hot glass by hypervelocity projectiles

Microcraters were formed in heated soda-lime glass by the normal incidence of spheres of plastic or fused silica with diameters between 0.8 and 4.5 microns and velocities between 2.5 and 10 km/s. The morphology of the craters in targets at temperatures up to 800 C is little different from those formed in unheated glass. Spallation still occurs to the same extent and above the same velocity threshold, but the spalls sag and sharp edges become dull in a few seconds at temperatures above the softening point. There is a small increase in the flow of glass from the central pit into a narrow lip at the higher temperatures, but this lip is often removed by spallation, especially at the higher velocities of impact. There is no evidence of a splashed lip with strings of melt overlying the spalled area. The results in conjunction with other evidence suggest that most lunar craters of micrometer size with a smooth central pit, splashed lip, and a spallation zone are the result of primary impacts.

Vedder, J. F.↗
NASA NTRS1976

Inlets for high angles of attack

Different inlet designs for high angle of attack STOL and VTOL applications were tested in a subsonic wind tunnel. Three removable entry lips having contraction ratios of 1.30, 1.34 and 1.38 were tested with a single diffuser. The internal contour of each entry lip was an ellipse with a major to minor axis of 2.0. Each lip and diffuser assembly was tested to determine its tolerance to angle of attack, first with a conventional centerbody and then with an extended centerbody. Results indicate that a large improvement in separation angle (determined as a function of lip contraction ratio and inlet flow) was obtained for the extended centerbody for all contraction ratios. Improved inlet tolerance to angle of attack was obtained by reducing the adverse pressure gradient downstream of the throat.

Miller, B. A.↗
NASA NTRS1977

Aeroacoustic performance of a scoop inlet

A low speed wind tunnel test demonstrated the aerodynamic and acoustic performance of a scoop inlet. Engine noise is directed upward by the extended lower lip of the scoop inlet. In addition, more of the scoop airflow comes in from above the inlet than below, leading to relatively higher surface velocities on the upper lip and lower surface velocities on the lower lip. These lower velocities on the lower lip result in a higher attainable angle of attack before internal flow separation occurs.

Abbott, J. M.↗
NASA NTRS1977

Aeroacoustic performance of a scoop inlet

Results of a low speed wind tunnel test program are presented which demonstrate the aerodynamic and acoustic performance of a scoop inlet. Engine noise that would normally propagate toward the ground is directed upward by the extended lower lip of the scoop inlet. In addition, more of the scoop airflow comes in from above the inlet than below, leading to relatively higher surface velocities on the upper lip and lower surface velocities on the lower lip. These lower velocities on the lower lip result in a higher attainable angle of attack before internal flow separation occurs.

Abbott, J. M.↗
NASA NTRS1978

Effect of design changes on aerodynamic and acoustic performance of translating-centerbody sonic inlets

An experimental investigation was conducted to determine the effect of design changes on the aerodynamic and acoustic performance of translating centerbody sonic inlets. Scale model inlets were tested in the Lewis Research Center's V/STOL wind tunnel. The effects of centerbody position, entry lip contraction ratio, diffuser length, and diffuser area ratio on inlet total pressure recovery, distortion, and noise suppression were investigated at static conditions and at forward velocity and angle of attack. With the centerbody in the takeoff position (retracted), good aerodynamic and acoustic performance was attained at static conditions and at forward velocity. At 0 deg incidence angle with a sound pressure level reduction of 20 dB, the total pressure recovery was 0.986. Pressure recovery at 50 deg was 0.981. With the centerbody in the approach position (extended), diffuser flow separation occurred at an incidence angle of approximately 20 deg. However, good performance was attained at lower angles. With the centerbody in the takeoff position the ability of the inlet to tolerate high incidence angles was improved by increasing the lip contraction ratio. However, at static conditions with the centerbody in the approach position, an optimum lip contraction ratio appears to exist, with both thinner and thicker lips yielding reduced performance.

Miller, B. A.↗
NASA NTRS1991

The spatial characteristics of the B helical mode for a choked axisymmetric nozzle

An acoustic near-field study was performed for an axisymmetric conical nozzle operated at a fully expanded Mach number of 1.3. The acoustic measurements were performed in the nozzle exit plane using multiple sensors arranged around the periphery of the nozzle. The acquired data were simultaneously digitized. The acoustic spatial characteristics, describing the large scale structure associated with the preferred shear layer instability mode, were determined for the dominant B screech mode. The nozzle was fitted with a lip thickening device to determine the effect of this geometric variable on the spatial structure of the jet. For the thin-lipped configuration, the flapping structure of the B screech mode was found to precess in a time-dependent manner about the jet axis. An increasing of the nozzle exit lip thickness altered the spatial characteristics of this mode from a flapping to a time-dependent flapping or spinning. Using the auto-bicoherence spectrum, frequency dependencies were found to exist in the acoustic data of the thick-lipped configuration. These dependencies may be related to the nonlinearity of the jet and/or the time-dependent nature of the B mode spatial structure.

Ponton, Michael K.↗
NASA NTRS1992

Application of computational fluid dynamics to the design of the film cooled STME subscale nozzle for the National Launch System

The status of computational fluid dynamics (CFD) calculations for the Space Transportation Main Engine (STME) film/dump cooled nozzle design is presented, with an emphasis on the timely impact of CFD on the design of the sub-scale nozzle coolant system. The following aspects of the sub-scale coolant delivery system were analyzed with CFD: 1) a design trade study of a mechanical flow splitting device for uniform distribution of the subsonic cavity flow, 2) a design trade study of the subsonic cavity lip to achieve film integrity, and 3) an analysis of the primary flow interaction with the core/secondary coolant streams. All design calculations were performed with the Generalized Aerodynamic Simulation Program (GASP), a 3-D, multi-block, generalized Navier-Stokes code capable of solving with frozen, finite-rate or equilibrium chemical kinetics. The initial design of the subsonic cavity flow used square posts to distribute the sonic orifice jets into a uniform flow. Calculations for this design indicated that an unacceptable mal-distribution of film occurred. Design modifications involving curved and slotted posts were computed in an effort to uniformly distribute the secondary coolant flow. Analysis of these configurations showed that although the flowfield improved in uniformity, it was still unacceptable, especially at higher feed pressures. Results from these studies were then incorporated into a design that resulted in the insertion of a porous metal ring into the subsonic cavity. Subsequent water flow model studies showed that this concept was successful in uniformly distributing flow exiting the cavity. In addition to the design of the subsonic cavity, CFD was also used to analyze the secondary coolant lip and the primary flow interaction with the core/secondary coolant streams. A series of calculations were first performed to modify the subsonic cavity lip contour. The flow over the modified lip was then computed simultaneously with the primary injectors to determine the impact of the subsonic coolant stream on the primary slot jets. Pressure, temperature, velocity, and coolant mass fraction contours are presented for these configurations. Information is given in viewgraph form.

Garrett, Joseph L.↗
NASA NTRS1992

Shock interference prediction using direct simulation Monte Carlo

The shock interaction produced when an incident shock impinges on an inlet cowl lip is investigated for a cowl lip radius of 0.1 in. and flight conditions of Mach 15 and 35-km altitude. This problem is of interest in the design of hypersonic flight vehicles because the interference heating at the cowl lip surface from such a shock interaction is expected to be very high and the design of adequate thermal protection in this region will be challenging. Noncontinuum effects may be significant at this combination of altitude and small dimensions. If this is so, a computational solution based on the Navier-Stokes equations could significantly overpredict the surface heating on the cowl lip. Therefore, a kinetic theory solution technique, direct simulation Monte Carlo (DSMC), is used to predict the flowfield and surface heating. The details of modeling this problem and some preliminary results are presented. The same qualitative flow patterns are seen with DSMC and a continuum solution of the shock interference case, but the peak heating predicted with DSMC is somewhat lower.

Carlson, Ann B.↗
NASA NTRS1995

Acoustic Study of B Helical Mode for Choked Axisymmetric Nozzle

An acoustic near-field study was performed for an axisymmetric conical convergent nozzle operating at a pressure ratio corresponding to a fully expanded Mach number of 1.3. The acoustic measurements were performed in the nozzle exit plane using multiple sensors arranged around the periphery of the nozzle. The acquired data were simultaneously digitized. The acoustic spatial characteristics, describing the large-scale structure associated with the preferred shear layer instability mode, were determined for the dominant B screech mode. The nozzle was fitted with a lip thickening device to determine the effect of this geometric variable on the spatial structure of the jet. For the thin-lipped configuration, the flapping structure of the B screech mode was found to precess in a time- dependent manner about the jet axis. Increasing of the nozzle exit lip thickness altered the spatial characteristics of this mode from a flapping to a time-dependent flapping or spinning. Using the autobicoherence spectrum, frequency dependencies were found to exist in the acoustic data of the thick-lipped configuration. These dependencies may be related to the nonlinearity of the jet and/or the time-dependent nature of the B mode spatial structure.

Ponton, Michael K.↗
NASA NTRS1947

Tests of Submerged Duct Installation on the Ryan FR-1 Airplane in the Ames 40- by 80-Foot Wind Tunnel

An investigation of an NACA submerged intake installation on the Ryan FR-1 was conducted to determine the full-scale aerodynamic characteristics of this installation. In addition, tests were conducted on the submerged inlet with revised entrance lips and deflectors to determine the configuration which would result in the best dynamic pressure recovery measured at the inlet for this installation without a major rework of the entrance. Stalling of the air flow over the inner lip surface created excessive dynamic pressure losses with the original entrance. The revised entrance produced a 12-percent increase in dynamic pressure recovery at the design high-speed inlet-velocity ratio and resulted in an improvement of thte critical-speed characteristics of the entrance lip. A complete redesign of the entrance including a decrease in ramp angle and adjustment of lip camber is necessary to secure optimum results from this submerged duct installation.

Martin, Norman J.↗
NASA NTRS2008

Transient Three-Dimensional Startup Side Load Analysis of a Regeneratively Cooled Nozzle

The objective of this effort is to develop a computational methodology to capture the startup side load physics and to anchor the computed aerodynamic side loads with the available data from a regeneratively cooled, high-aspect-ratio nozzle, hot-fired at sea level. The computational methodology is based on an unstructured-grid, pressure-based, reacting flow computational fluid dynamics and heat transfer formulation, a transient 5 s inlet history based on an engine system simulation, and a wall temperature distribution to reflect the effect of regenerative cooling. To understand the effect of regenerative wall cooling, two transient computations were performed using the boundary conditions of adiabatic and cooled walls, respectively. The results show that three types of shock evolution are responsible for side loads: generation of combustion wave; transitions among free-shock separation, restricted-shock separation, and simultaneous free-shock and restricted shock separations; along with the pulsation of shocks across the lip, although the combustion wave is commonly eliminated with the sparklers during actual test. The test measured two side load events: a secondary and lower side load, followed by a primary and peak side load. Results from both wall boundary conditions captured the free-shock separation to restricted-shock separation transition with computed side loads matching the measured secondary side load. For the primary side load, the cooled wall transient produced restricted-shock pulsation across the nozzle lip with peak side load matching that of the test, while the adiabatic wall transient captured shock transitions and free-shock pulsation across the lip with computed peak side load 50% lower than that of the measurement. The computed dominant pulsation frequency of the cooled wall nozzle agrees with that of a separate test, while that of the adiabatic wall nozzle is more than 50% lower than that of the measurement. The computed teepee-like formation and the tangential motion of the shocks during lip pulsation also qualitatively agree with those of test observations. Moreover, a third transient computation was performed with a proportionately shortened 1 s sequence, and lower side loads were obtained with the higher ramp rate.

Wang, Ten-See↗
NASA NTRS2011

A Zero-Gravity Cup for Drinking Beverages in Microgravity

To date, the method for astronauts to drink liquids in microgravity or weightless environments is to suck the liquid from a bag or pouch through a straw. A new beverage cup works in microgravity and allows astronauts to drink liquids from a cup in a manner consistent with that on Earth. The cup is capable of holding beverages with an angled channel running along the wall from the bottom to the lip. In microgravity, a beverage is placed into the cup using the galley dispenser. The angled channel acts as an open passage that contains only two sides where capillary forces move the liquid along the channel until it reaches the top lip where the forces reach an equilibrium and the flow stops. When one sips the liquid at the lip of the channel, the capillary force equilibrium is upset and more liquid flows to the lip from the reservoir at the bottom to re-establish the equilibrium. This sipping process can continue until the total liquid contents of the cup is consumed, leaving only a few residual drops about the same quantity as in a ceramic cup when it is drunk dry on Earth.

Pettit, Donald R.↗
NASA NTRS2019

Scale–Resolving Simulations of a Fundamental Trailing–Edge Cooling Slot Using a Discontinuous–Galerkin Spectral–Element Method

The accurate prediction of turbulent mixing in high-pressure turbines that incorporate various airfoil surface-cooling strategies is becoming increasing critical to the design of modern gas turbine engines where the quest for improved efficiency is driving compressor overall pressure ratios and turbine inlet temperatures to much higher levels than ever before. In the present paper, a recently developed computational capability for accurate and efficient scale–resolving simulations of turbomachinery is extended to study the turbulent mixing mechanism of a simplified abstraction of an airfoil trailing-edge cooling slot - a plane wall jet with finite lip thickness discharging into an ambient flow. The computational capability is based on an entropy– stable, discontinuous–Galerkin approach that extends to arbitrarily high orders of spatial and temporal accuracy. The numerical results show that the present simulations capture the trends observed in the experiments. Discrepancies between the simulations and experiments are believed to be due to differences in the inflow profiles and tunnel side–wall effects. The thick lip configuration leads to a thicker wake and higher unsteadiness in the wall jet compared to the thin lip. A detailed comparison of the turbulent flowfields is presented to highlight differences arising due to lip thickness variations.

Scale Resolving↗
DOE OSTI2020

U-Pb zircon age constraints on the earliest eruptions of the Deccan Large Igneous Province, Malwa Plateau, India

Climate instability driven by emission of volatiles during emplacement of large igneous provinces (LIPs) is frequently invoked as a potential cause of mass extinctions. However, documenting this process in the geologic record requires a holistic understanding of eruption rates, the location of eruptive centers, and potential sources of climate-changing volatiles. We present new chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon geochronology from Malwa Plateau basalts on the northern margin of the Deccan LIP, India. These basalts have been previously interpreted as either an extension of the province's main volcanic stratigraphy or as an independent eruptive center active up to millions of years prior to the main eruptive phase. Our data instead demonstrate that the lower Malwa Plateau basalts are temporally correlative with the first pulse of Deccan volcanism and provide new constraints on its initiation and duration. Paleomagnetic data further indicate that upper Malwa Plateau basalts may be age-equivalent to the second, third, and fourth pulses of Deccan volcanism. The relative thicknesses of age-equivalent packages of basalt are consistent with eruption of the Deccan LIP from a southward-migrating eruptive center. The first eruptive pulse is coeval with a ~200 kyr Late Maastrichtian warming event preserved globally in contemporaneous stratigraphic sections. We propose that the first pulse of Deccan magmatism was more voluminous in the north, where it erupted through organic-rich sedimentary rocks of the Narmada-Tapti rift basin. Thermal metamorphism of these sediments could have been a source of sufficient CO 2 to drive the Late Maastrichtian warming event, which if true would reconcile the apparent dampened warming signals associated with later Deccan eruptive pulses.

58 GEOSCIENCES↗
DOE OSTI2025

Size-Selective Nanoporous Atomically Thin Graphene Separators for Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are extensively researched for their high energy densities but are hindered by the lithium polysulfide (LiPS) shuttling effect, which results in poor cyclability. A popular mitigation strategy is separator modification, where a LiPS trapping material is slurry-coated onto a conventional microporous polypropylene (PP) separator. This additional mass and volume unfortunately compromise the overall energy density of the LSB. This study aims to take a separator modification approach that avoids this issue. Nanoporous atomically thin membranes (NATMs) made of graphene are gaining attention for their scalable synthesis, tunable pore size, and negligible pore length. Herein, we apply a well-characterized graphene NATM for reasons similar to those of a size-selective interlayer in LSBs. The tailored pore size of ∼0.7–1.0 nm and atomic thinness facilitate the passage of Li + (solvated ionic diameters ∼0.54–1.26 nm) and blockage of larger LiPS (solvated ionic diameters ∼0.81–1.69 nm) without adding significant impedances or mass. The sulfur confinement is confirmed through scanning electron microscopy and energy-dispersive X-ray spectroscopy elemental analysis of the Li anode. An LSB with a NATM@PP separator shows virtually no capacity loss over 150 cycles, demonstrating efficacy of size-selective molecular sieving using NATMs in LSBs.

battery separator↗