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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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Forced Convection Boiling and Critical Heat Flux of Ethanol in Electrically Heated Tube Tests

Electrically heated tube tests were conducted to characterize the critical heat flux (transition from nucleate to film boiling) of subcritical ethanol flowing at conditions relevant to the design of a regeneratively cooled rocket engine thrust chamber. The coolant was SDA-3C alcohol (95% ethyl alcohol, 5% isopropyl alcohol by weight), and tests were conducted over the following ranges of conditions: pressure from 144 to 703 psia, flow velocities from 9.7 to 77 ft/s, coolant subcooling from 33 to 362 F, and critical heat fluxes up to 8.7 BTU/in(exp 2)/sec. For the data taken near 200 psia, critical heat flux was correlated as a function of the product of velocity and fluid subcooling to within +/- 20%. For data taken at higher pressures, an additional pressure term is needed to correlate the critical heat flux. It was also shown that at the higher test pressures and/or flow rates, exceeding the critical heat flux did not result in wall burnout. This result may significantly increase the engine heat flux design envelope for higher pressure conditions.

Meyer, Michael L.↗
NASA NTRS2003

Improvement in diastolic intraventricular pressure gradients in patients with HOCM after ethanol septal reduction

We sought to validate measurement of intraventricular pressure gradients (IVPG) and analyze their change in patients with hypertrophic obstructive cardiomyopathy (HOCM) after ethanol septal reduction (ESR). Quantitative analysis of color M-mode Doppler (CMM) images may be used to estimate diastolic IVPG noninvasively. Noninvasive IVPG measurement was validated in 10 patients undergoing surgical myectomy. Echocardiograms were then analyzed in 19 patients at baseline and after ESR. Pulsed Doppler data through the mitral valve and pulmonary venous flow were obtained. CMM was used to obtain the flow propagation velocity (Vp) and to calculate IVPG off-line. Left atrial pressure was estimated with the use of previously validated Doppler equations. Data were compared before and after ESR. CMM-derived IVPG correlated well with invasive measurements obtained before and after surgical myectomy [r = 0.8, P < 0.01, Delta(CMM - invasive IVPG) = 0.09 +/- 0.45 mmHg]. ESR resulted in a decrease of resting LVOT systolic gradient from 62 +/- 10 to 29 +/- 5 mmHg (P < 0.001). There was a significant increase in the Vp and IVPG (from 48 +/- 5to 74 +/- 7 cm/s and from 1.5 +/- 0.2 to 2.6 +/- 0.3 mmHg, respectively, P < 0.001 for both). Estimated left atrial pressure decreased from 16.2 +/- 1.1 to 11.5 +/- 0.9 mmHg (P < 0.001). The increase in IVPG correlated with the reduction in the LVOT gradient (r = 0.6, P < 0.01). Reduction of LVOT obstruction after ESR is associated with an improvement in diastolic suction force. Noninvasive measurements of IVPG may be used as an indicator of diastolic function improvement in HOCM.

NASA Program Biomedical Research and Countermeasur↗
NASA NTRS2005

Protection of 2-(3-Thienyl)ethanol with 3-Thienylacetic Acid and Hard Cross- Linked Conducting Films by Electropolymerization of the Ester

The ester (compound 1) of 2-(3-thienyl)ethanol (T-etOH) with 3-thienylacetic acid was synthesized as a monomer whose two thiophene groups could be electropolymerized independently, becoming members of different polymer chains in a highly-crosslinked highly-insoluble polymer. Indeed, 1 was electropolymerized successfully alone and together with 3-methylthiophene (3MeT). Films of poly(1) are hard (3H, as opposed to less than 6B for poly(3MeT)), and the close proximity of the polymeric strands creates pi-stacking interactions. The behavior of 1 suggests that by: (a) limiting the potential used for the oxidation of monomeric esters of T-etOH at the foot of their oxidation waves (less than 1.8 V vs. Ag/AgCl); and, (b) compensating for the decrease in the electrogenerated radical concentration by increasing the monomer concentration, practically all esters of T-etOH should be electropolymerizable. This was confirmed by durable film formation from the archetypical ester of T-etOH, the 2-(3-thienyl)ethyl acetate (T-etOAc), whose homo-electropolymerization is reported for the first time.

Leventis, Nicholas↗
NASA NTRS2017

Spontaneous Ignition of Hydrothermal Flames in Supercritical Ethanol Water Solutions

Results are reported from recent tests where hydrothermal flames spontaneously ignited in a Supercritical Water Oxidation (SCWO) Test Cell. Hydrothermal flames are generally categorized as flames that occur when appropriate concentrations of fuel and oxidizer are present in supercritical water (SCW); i.e., water at conditions above its critical point (218 atm and 374 C). A co-flow injector was used to inject fuel, comprising an aqueous solution of 30-vol to 50-vol ethanol, and air into a reactor held at constant pressure and filled with supercritical water at approximately 240 atm and 425 C. Hydrothermal flames auto-ignited and quickly stabilized as either laminar or turbulent diffusion flames, depending on the injection velocities and test cell conditions. Two orthogonal views, one of which provided a backlit shadowgraphic image, provided visual observations. Optical emission measurements of the steady state flame were made over a spectral range spanning the ultraviolet (UV) to the near infrared (NIR) using a high-resolution, high-dynamic-range spectrometer. Depending on the fuel air flow ratios varying degrees of sooting were observed and are qualitatively compared using light absorption comparisons from backlit images.

hydrothermal flame↗
NASA NTRSDate not supplied

Hydrogen Peroxide-Water-Ethanol-Monopropellant Blend for CubeSat Propulsion

Monopropellant propulsion that provides high performance and low hazards compared to state-of-art hydrazine are being investigated under NASA, DOD and commercially sponsored green propellant research and development programs. This NASAeffort looks at phosphate stabilized 50% hydrogen peroxide/water –ethanol blends to evaluate their stability and combustion behavior in submillimeter diameter microtube combustion apparatus for cubesat propulsion applications. Exploratory 7-day stabilitytests find no pressure rise in a sealed test tube environment at room temperature indicating at least short term stability of the mixture. Temperature rise during combustion testing in resistively heated nickel microtube apparatus shows that micro-combustion is achieved in the tube. Propellant density is approximately 1.2 g/cm3compared to 1.0 g/cm3for hydrazine. Theoretical specific impulse of the stoichiometric blend is 219 s at a chamber pressure of 20 psia and an area ratio of 30:1. Density-specific impulseof this blendis263 swhile hydrazine is only about 215-220 sin small reaction control system thrusters. This provides about 20-22% more density-specific impulse for the cubesat compared to hydrazine. The theoreticalcombustion temperature is2168°F, whichis thermally compatible with stainless steel materials of constructionand the nickel catalystused in the tests. Combustion test results are given for stoichiometric, as well as fuel-leanand fuel-richpropellant formulations. Thesetests focus on thermally and catalytically supported combustionin the microtube, whichrequires a microtube preheat temperature of about 900°F and sufficient residence time to achieve combustion that is stable and anchored in the tubewithout blowing through the tube unreacted. Thrust class is expected to be in the 10 mN range based on flow rate and estimated specific impulse.Power requirements are generally below 25 Wto heat the tube. Steady state combustion testing is typically conducted for 3 minutes and shows littledegradation of the hardware over multiple test cyclesindicating thatthere is little catalyst degradation over time and littlecatalyst deactivation due tothe phosphate stabilizer inthe hydrogen peroxide.

Monopropellant↗
NASA NTRSDate not supplied

Hydrogen Peroxide-Water-Ethanol Monopropellant Blend for CubeSat Propulsion

Monopropellant propulsion that provides high performance and low hazards compared to state-of-art hydrazine are being investigated under NASA, DOD and commercially sponsored green propellant research and development programs. This NASA effort looks at phosphate stabilized 50% hydrogen peroxide/water –ethanol blends to evaluate their stability and combustion behavior in submillimeter diameter microtube combustion apparatus for cubesat propulsion applications. Exploratory 7-day stability tests find no pressure rise in a sealed test tube environment at room temperature indicating at least short term stability of the mixture. Temperature rise during combustion testing in resistively heated nickel microtube apparatus shows that micro-combustion is achieved in the tube. Propellant density is approximately 1.2 g/cu.cm compared to 1.0 g/cu.cm for hydrazine. Theoretical specific impulse of the stoichiometric blend is 219 s at a chamber pressure of 20 psia and an area ratio of 30:1. Density-specific impulse of this blend is 263 s while hydrazine is only about 215-220 s in small reaction control system thrusters. This provides about 20-22% more density-specific impulse for the cube sat compared to hydrazine. The the oretical combustion temperature is 2168°F, which is thermally compatible with stainless steel materials of construction and the nickel catalyst used in the tests. Combustion test results are given for stoichiometric, as well as fuel-lean and fuel-rich propellant formulations. These tests focus on thermally and catalytically supported combustion in the microtube, which requires a microtube preheat temperature of about 900°F and sufficient residence time to achieve combustion that is stable and anchored in the tube without blowing through the tube unreacted. Thrust class is expected to be in the 10 m N range based on flow rate and estimated specific impulse. Power requirements are generally below 25 W to heat the tube. Steady state combustion testing is typically conducted for 3 minutes and shows little degradation of the hardware over multiple test cycles indicating that there is little catalyst degradation over time and little catalyst deactivation due to the phosphate stabilizer in the hydrogen peroxide.

Monopropellant↗
NASA NTRS2020

Determination of Autogenous Ignition Temperature for Isopropyl Alcohol and Ethanol

As part of a recent liquid rocket engine shutdown investigation, a commercial partner requested that NASA provide the autogenous ignition (or autoignition) temperature (AIT) of isopropyl alcohol (IPA). NASA provided the available data, but the data were somewhat scattered, likely due to test configuration and test technique differences. NASA Engineering and Safety Center (NESC) support was requested to experimentally determine the AIT of IPA and ethanol, both of which are extensively applied to propulsion systems. This report contains the outcome of the NESC assessment.

Autoignition Temperature; Isopropyl Alcohol; Comme↗
DOE OSTI2020

Method of converting ethanol to higher alcohols

A method and catalyst for forming higher alcohols from lower alcohol feedstocks. In one application a highly selective and stable copper pseudo-single-atom supported on MgO—Al2O3 catalyst is provided which provides ethanol condensation to higher alcohols at ˜50% yields and ˜85% selectivity is demonstrated with stable catalyst lifetime over 500 hours in a continuous flow system. In some applications a Guerbet condensation process is further utilized to yield a higher alcohol at a selectivity of near ˜90%.

09 BIOMASS FUELS↗
DOE OSTI2020

System and method for extracting ethanol from a fermentation broth

The present invention is directed to a system and method for producing an organic compound using fermentation wherein multiple components of the system are recycled within the system. The system and method allow for extraction of a high concentration of the organic compound from the fermentation broth in a continuous system that allows recycling of the biomass, aqueous fermentation broth and extraction solvents. The system and method are particularly well adapted for producing and extracting ethanol.

09 BIOMASS FUELS↗
DOE OSTI2024

System and method for extracting ethanol from a fermentation broth

The present invention is directed to a system and method for producing an organic compound using fermentation wherein multiple components of the system are recycled within the system. The system and method allow for extraction of a high concentration of the organic compound from the fermentation broth in a continuous system that allows recycling of the biomass, aqueous fermentation broth and extraction solvents. The system and method are particularly well adapted for producing and extracting ethanol.

Abbas, Charles↗
DOE OSTI2023

Low-Temperature Plasma Assisted Kinetics Study of Ethanol

Abstract: Non- equilibrium plasma assisted kinetics of ethanol at 0.5 atm over a temperature range of 523-1203 K were studied at stoichiometric conditions by using a plasma flow reactor (PFR). The effects of plasma chemistry on fuel and its influence on neutral chemistry is decoupled with both experimental and modelling efforts. Enhanced reactivity was observed experimentally in both plasma-assisted oxidation and pyrolysis cases with fuel consumption beginning at temperatures as low as 523 K. Absolute fuel consumption was observed at temperatures nearly 200 K earlier than pure thermal reactions highlighting the effectiveness of non-equilibrium plasma to promote reactivity. Modelling results illustrated the effect of electron impact reactions towards accelerating fuel consumption and promoting low temperature chemistry by generating excited state N2 and reactive O and OH radicals.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗